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PROGRESS REPORT<br />

Euratom–<strong>ENEA</strong> Association<br />

fusion activities<br />

2010<br />

ITALIAN NATIONAL AGENCY FOR NEW TECHNOLOGIES ENERGY AND SUSTAINABLE<br />

ECONOMIC DEVELOPMENT<br />

Nuclear Fusion Unit


This report was prepared by the Scientific Publications Office from contributions provided by the scientific and technical<br />

staff of <strong>ENEA</strong>’s Nuclear Fusion Unit<br />

Scientific e<strong>di</strong>tors: Paola Batistoni, Gregorio Vlad<br />

Cover, artwork and design/composition: Marisa Cecchini<br />

English revision: Laura Bocci<br />

See http://www.fusione.enea.it for copy of this report<br />

FNG with an assembled ITER mock–up<br />

Ra<strong>di</strong>ography of a plastic<br />

foil with holes<br />

ITER <strong>di</strong>vertor IVT qualification<br />

prototype manufactured by<br />

<strong>ENEA</strong>–Ansaldo<br />

Pre-compression ring<br />

<strong>di</strong>smantling after test<br />

Published by:<br />

<strong>ENEA</strong> - Servizio Diffusione Tecnologie<br />

E<strong>di</strong>zioni Scientifiche,<br />

Centro Ricerche Frascati, Tel.: +39(06)9400 5016<br />

C.P. 65 Fax: +39(06)9400 5015<br />

00044 Frascati Rome (Italy) e-mail: marisa.cecchini@enea.it


progress report<br />

2010<br />

001<br />

2010<br />

Progress Report<br />

Euratom - <strong>ENEA</strong> Association<br />

Fusion Activities


Contents<br />

006 Preface<br />

008 Anniversary<br />

010 Magnetic Confinement<br />

010 Introduction<br />

011 FTU Facility<br />

011 Summary of the machine operation<br />

013 FTU Experimental Activity<br />

013 Lower hybrid<br />

016 Alfvén eigenmodes: modeling, experimental results<br />

and future plans<br />

017 Electron cyclotron<br />

021 Liquid lithium experiments<br />

023 Diagnostic developments<br />

029 Plasma–wall interaction<br />

Euratom–<strong>ENEA</strong><br />

Association<br />

2010annual<br />

fusion<br />

activities<br />

030 Plasma Theory<br />

030 Alfvén modes in the presence of a magnetic island<br />

031 Nonlocal theory of energetic–particle–induced<br />

geodesic acoustic mode<br />

032 Kinetic structures of shear Alfvén and acoustic wave<br />

spectra in burning plasmas<br />

032 ITPA benchmarking activity using HMGC<br />

033 TAE eigenfunctions for ITER magnetic <strong>di</strong>agnostics<br />

033 ITM–TF activities<br />

033 The new hybrid MHD–gyrokinetic code: HYMAGYC<br />

034 Applications and further implementation of the<br />

eXtended HMGC hybrid code<br />

035 Parametric form of equilibrium particle <strong>di</strong>stribution<br />

functions for implementations in HMGC<br />

035 Design of energetic particle equilibrium <strong>di</strong>stribution<br />

functions<br />

036 A new model for self–organized critical dynamics, with<br />

implication of the fishbone–like instability cycle<br />

037 Asymptotic techniques in the study of the propagation<br />

of high frequency (lower hybrid range) electromagnetic<br />

waves<br />

037 Analytical and numerical stu<strong>di</strong>es of the cold<br />

electromagnetic LH wave equation in the mode<br />

conversion regimev<br />

037 Hamiltonian perturbation theory in studying the LH<br />

wave propagation in burning plasmas<br />

038 The propagation and absorption of lower hybrid<br />

waves in H–mode plasma with very sharp density<br />

gra<strong>di</strong>ent at the pedestal<br />

038 Tritium minority heating with mode conversion of fast<br />

waves<br />

038 Stellar winds or matter–jet seeds from <strong>di</strong>sk plasma<br />

configuration


progress report<br />

2010<br />

003<br />

038 JET Collaboration<br />

039 Pellet stu<strong>di</strong>es<br />

039 High beta operation<br />

040 Dust<br />

040 L to H mode transition<br />

040 Safety factor profile determination<br />

041 Upgrade of neutron profile monitor (KN3N)<br />

041 Elaboration of JET programme for 2011<br />

041 Coor<strong>di</strong>nation of other Italian partners<br />

042 Plasma control<br />

042 References<br />

046 Fusion Advanced Stu<strong>di</strong>es Torus<br />

046 Introduction<br />

047 Physics<br />

047 Transport simulations<br />

048 Energetic particle physics in H–mode scenario with combined NNBI and ICRH<br />

049 Plasma–Wall interaction activities and optimization of the <strong>di</strong>vertor geometry<br />

049 Diagnostics<br />

050 Design Description<br />

050 Divertor design<br />

051 First wall design<br />

052 Vacuum vessel design<br />

052 Toroidal field coil system<br />

053 Toroidal field ripple reduction<br />

053 Poloidal field coil system<br />

054 Poloidal field coil system flexibility and plasma control<br />

054 Cooling system<br />

054 Remote handling<br />

055 References<br />

056 Technology Programme<br />

056 Introduction<br />

057 Divertor, First Wall, Vacuum Vessel and Shield<br />

057 Manufacturing technology for the ITER inner vertical target<br />

057 Qualification of ultrasonic non–destructrive testing method for plasma facing<br />

components<br />

058 Analysis of the ITER <strong>di</strong>vertor cassettes<br />

060 Breeder Blanket and Fuel Cycle<br />

060 European Bree<strong>di</strong>ng Blanket Test Facility design and construction<br />

060 TRIEX loop for studying technologies of tritium extraction from Pb–17Li<br />

060 Electromagnetic load analysis for the design of the blanket manifold pipe<br />

concept for ITER<br />

061 Development of method for highly tritiated water handling in ITER tritium plant<br />

061 Training activities<br />

062 Magnet and Power Supply


progress report<br />

2010<br />

004<br />

062 Optimization of the toroidal field ripple reduction system<br />

062 Three–<strong>di</strong>mensional magneto–static analyses for ITER<br />

063 Analysis of the ripple effects due to the ferromagnetic materials in the NBI<br />

magnetic shields and the test blanket modules<br />

063 Assessment of the NBI magnetic field reduction system<br />

064 Assessment of the effects of the ferromagnetic material in the ITER buil<strong>di</strong>ng<br />

structures<br />

065 Pre–compression rings final design qualification<br />

065 Remote Handling and Metrology<br />

065 ITER in vessel viewing system<br />

068 Neutronics<br />

068 Neutronics shiel<strong>di</strong>ng experiment on a mock–up of ITER: dose measurement in<br />

the magnet coils<br />

069 ITER <strong>di</strong>agnostic port integration: development of the ITER MCNP 40° model<br />

069 Neutronic calculations in support of the design of the ITER high resolution<br />

neutron spectrometer<br />

070 Three–<strong>di</strong>mensional neutronic analysis of the ITER in–vessel coils<br />

072 Neutron and gamma spectra behind ITER blanket modules and in <strong>di</strong>vertor<br />

072 Neutronic analysis of ITER <strong>di</strong>vertor rails<br />

073 Development of a high resolution compact neutron spectrometry using<br />

<strong>di</strong>amond detectors<br />

073 Measurement of Ti profiles with the ITER ra<strong>di</strong>al neutron camera<br />

074 Measurement of fuel ratio profiles with the ITER ra<strong>di</strong>al neutron camera<br />

075 Materials<br />

075 Development of a multi–scale methodology for composite structural modelling<br />

and validation of modelling procedure by mechanical testing<br />

075 Safety and Environment, Power Plant Conceptual Stu<strong>di</strong>es and Socio Economics<br />

075 Dust mobilization stu<strong>di</strong>es<br />

076 Validation of the PACTITER computer code and related fusion specific<br />

experiments in CORELE loop<br />

077 Safety analyses by hazard and operability stu<strong>di</strong>es<br />

078 Broad Approach<br />

078 JT–60SA<br />

079 International Fusion Materials Irra<strong>di</strong>ation Facility<br />

082 DEMO R&D in the Broader Approach activities<br />

083 JET Fusion Technology<br />

083 JET housekeeping wastes detritiating<br />

084 GEM–based neutron detector for 2.5 and 14 MeV<br />

084 Compact neutron spectrometer<br />

085 Cryogenics<br />

085 Liquid helium service<br />

086 References<br />

088 Superconductivity<br />

088 Introduction<br />

089 Cable–in–Conduit Conductor<br />

089 Manufacturing of ITER poloidal field conductor samples


progress report<br />

2010<br />

005<br />

089 Compaction of ITER CS empty tubes<br />

090 Feasibility verification of the superconducting proposal of the TF magnet<br />

system of FAST<br />

090 Heat exchanger design for the 30 kA current leads of <strong>ENEA</strong> CICC upgrade<br />

facility<br />

090 Study on the effect of strand ben<strong>di</strong>ng on the voltage–current characteristic of<br />

Nb 3 Sn CICC<br />

091 Role of the cross section geometry in rectangular Nb 3 Sn CICC performances<br />

091 R&D on Superconducting Materials<br />

091 Study on Nb 3 Sn strand<br />

092 Study on NbTi strands<br />

092 Quality control monitoring of NbTi strands for JT–60SA TF coils<br />

093 ITER NbTi strand benchmarking tests<br />

093 High Temperature Superconductors<br />

093 Study of Ni–Cu based alloy tapes for YBCO coated conductor application<br />

094 Oxidation behaviour of the Ni–W and CeO 2 interface: role of Pd inter–layer<br />

094 Low fluorine YBCO MOD<br />

094 Transport properties improvement in low fluorine YBCO MOD with artificial<br />

pinning sites<br />

095 Conceptual design of YBCO coil for the toroidal magnetic system of ISTTOK<br />

tokamak<br />

096 Inertial Fusion<br />

097 Fusion & Industry<br />

099 Quality Assurance<br />

100 Publications and Events<br />

100 Publications<br />

100 Articles<br />

106 Articles in course of publication<br />

109 Contributions to conferences<br />

116 Workshops and Seminars<br />

116 Workshops<br />

117 Seminars<br />

117 Patents<br />

118 Miscellaneous (*)<br />

118 The Fleischman&Pons Effect Through the Materials Science Development<br />

118 Pd–Based Membranes<br />

119 AGILE and LOFT<br />

120 Digital Phase Detector for the RF Interferometer for Mini Helicon Space Thruster<br />

121 References<br />

122 Organization Chart<br />

124 Abbreviations and Acronyms<br />

(*) Not in Association framework


progress report<br />

2010<br />

006<br />

Preface<br />

Euratom–<strong>ENEA</strong><br />

Association<br />

2010annual<br />

fusion<br />

activities


008<br />

progress report<br />

2010<br />

Anniversary<br />

50 th Anniversary EURATOM–<strong>ENEA</strong> Association on Fusion<br />

Spurred by Edoardo Amal<strong>di</strong> and with the collaboration of Enrico Persico and Franco Rasetti, starting in 1957<br />

Bruno Brunelli had gathered a small group of scientists of CNEN (today <strong>ENEA</strong>) and of Euratom who began<br />

a research activity on plasma physics and on problems related to thermonuclear fusion at the Institute of<br />

Physics of the University of Rome. In 1960 this activity was transferred to the CNEN Research Centre in<br />

Frascati where a new buil<strong>di</strong>ng was erected for the new Laboratorio Gas Ionizzati. The contract of association<br />

Euratom–CNEN was signed in the same year in attachment to the prece<strong>di</strong>ng French contract of association<br />

Euratom–CEA. In this way the Italian Fusion Program was started.<br />

After 50 years, the past and present lea<strong>di</strong>ng actors of fusion research have gathered on 8 July 2010 at <strong>ENEA</strong><br />

Centre in Frascati to celebrate this important anniversary. Under–secretary of State – Ministry of Economic<br />

Development, Stefano Saglia, <strong>ENEA</strong> Commissioner, Giovanni Lelli, and Euratom Director, Octavi Quintana<br />

Trias, attended the ceremony. In their addresses they emphasized the continuously increasing role, both in<br />

fusion physics and technology, played by Italy in the<br />

European Fusion Program, thanks to strong<br />

determination and capability to adapt to the new<br />

challenges.<br />

The volume describing the activities carried out by<br />

EURATOM–<strong>ENEA</strong>, written in the occasion of the 50th<br />

anniversary of the Association<br />

Speeches were delivered by the Italian<br />

representative in CCE–FU, Romano Toschi, the<br />

EFDA leader Francesco Romanelli, the Chairman<br />

of the Governing Board of Fusion for Energy,<br />

Carlos Varandas, the Head of ITER Department<br />

of Fusion for Energy, Maurizio Gasparotto, the<br />

President of Consorzio RFX, Giorgio Rostagni, the<br />

Director of Istituto <strong>di</strong> Fisica del Plasma – CNR,<br />

Maurizio Lontano, and by the Director of <strong>ENEA</strong><br />

Fusion Technical Unit, Aldo Pizzuto. Looking over<br />

the past 50 years, at the experiments that have<br />

marked the more significant and outstan<strong>di</strong>ng results<br />

obtained, they testified how fusion science has<br />

achieved its success through the ability to evolve<br />

from pure research activity confined in few<br />

laboratories, into a complex system involving<br />

physics, technology and engineering research, and<br />

close collaboration also with university and<br />

industrial worlds. Thanks to this capability, it has<br />

been possible to face increasingly deman<strong>di</strong>ng<br />

challenges, such as FT, FTU and RFX, and support


progress report<br />

2010<br />

009<br />

the involved industry with the necessary<br />

technological know – how. The wealth of<br />

experience acquired has proved to be<br />

extremely important in the development of<br />

JET and later in ITER, and is now the<br />

source of technological activities for the<br />

fusion carried out in <strong>ENEA</strong> today.<br />

In the recent years, as a new phase has<br />

begun with the start of ITER construction,<br />

the EURATOM – <strong>ENEA</strong> association has<br />

launched a new, high level programme for<br />

our Country to maintain its position in the<br />

forefront, based on a strengthened<br />

collaboration among the national partners,<br />

<strong>ENEA</strong>, CNR, Consorzio RFX and many<br />

Universities, and on a full integration with<br />

the activities carried out in the other<br />

European Countries. A closer relationship<br />

with the national industry has been<br />

established, with initiatives to promote its<br />

participation in ITER construction, and<br />

with provisions for participation in<br />

procurements using technologies developed<br />

in our laboratories.<br />

The celebration of 50th anniversary EURATOM-<strong>ENEA</strong> Association<br />

on Fusion at the <strong>ENEA</strong> Frascati centre on 8th July 2010<br />

The future relies on a new experiment,<br />

FAST, that can serve as a European and<br />

global research infrastructure on which to<br />

develop new knowledge of both physics and<br />

technology and to train scientists and<br />

technologists in view of ITER exploitation<br />

and the design of the demonstration<br />

reactor.<br />

1960–2010, fifty years characterized by<br />

passion and enthusiasm. The wish is that<br />

many others with enthusiasm and passion<br />

will follow with the awareness that fusion<br />

energy is a goal too important for future<br />

generations to miss.<br />

Yvan Capuet for EURATOM and Giovanni Lelli Commissioner for<br />

<strong>ENEA</strong> slicing the celebrating cake


010<br />

progress report<br />

2010<br />

chapter 1<br />

magneticconfinement<br />

The alternation of extremely scientifically productive years with technically critical ones seems to continue on FTU.<br />

Following the very productive year 2009, in 2010 the FTU time effectively used for the experimental activity has been<br />

extremely limited. The spring campaign was devastated by a series of vacuum leaks and eventually ended by a failure on<br />

the flywheel generator fee<strong>di</strong>ng the toroidal magnet. The autumn campaign was affected by several failures, mostly linked<br />

to poloidal circuits, producing at the end only a few shots useful for experimental programmes.<br />

As a consequence, during the 2010 year, more emphasis was given to completion of analyses of existing data and of new<br />

realisation on <strong>di</strong>agnostic and heating systems.<br />

However reduced in number, plasma operations were always benefitting of liquid lithium limiter, either used to limit the<br />

plasma or to con<strong>di</strong>tion the walls through depositing lithium on plasma facing surfaces. In such <strong>di</strong>scharges pellet were<br />

successfully injected for the first time, obtaining extremely peaked density profiles at very high density values as high as<br />

6×10 20 m –3 . Detailed linear microstability analysis was performed on lithized <strong>di</strong>scharges, proposing a possible mechanism<br />

for generating the density peaking. A detailed analysis has also been completed for the <strong>di</strong>scharges were, thanks to edge<br />

optimisation, it was demonstrated that lower hybrid (LH) waves can penetrate plasmas with ITER like density profile.<br />

These results, relevant for future applications of LH waves have been published in Nature Communication and have<br />

triggered a multi-machine joint experiment coor<strong>di</strong>nated by International Tokamak Physical Activity (ITPA)– Integrated<br />

Operation Scenario (IOS) group. More experiments, at higher power, are planned on FTU to quantify the LH current<br />

drive (CD) in these con<strong>di</strong>tions as well as to complete the systematic comparisons between experiments and theory of<br />

electron fishbones in the frame of the general fishbone–like <strong>di</strong>spersion relation. Looking forward to a positive decision for<br />

future application of LH to ITER, a complete revision of the system design for ITER has been also completed in<br />

collaboration with CEA Association.<br />

Experimental activities on electron cyclotron (EC) physics have been conducted at high priority on FTU. Runaway<br />

electrons have been suppressed; applying EC waves in heating scheme during the flattop phase of the <strong>di</strong>scharge, at an<br />

electric field value a factor ∼2 larger than the pre<strong>di</strong>cted collisional threshold field, E R ∼0.09×n e (10 20 m –3 ). EC on FTU<br />

has contributed to ITPA joint experiments on assisted breakdown and on MHD control in particular controlling sawteeth<br />

period through the localization of EC waves (injected in heating and CD scheme) with respect to q=1 surface. These<br />

experiments will greatly benefit from the installation of the new real time steerable antenna, that will inject 0.5 MW of<br />

EC waves through two front mirrors real time steerable poloidally and toroidally. The launcher has been fully tested in<br />

laboratory, achieving all design performances, and was ready to be installed on FTU in the 2010–2011 shutdown.<br />

By end of 2010, also two new <strong>di</strong>agnostics were completed and fully tested in laboratory. A new electro–optic probe able<br />

to simultaneously detect the electric spike and the ionization ra<strong>di</strong>ation generated by the impact of dust particles and a<br />

fast camera, which, able of up to 500000 frames/s, will allow <strong>di</strong>agnosing fast plasma evolution from breakdown to<br />

<strong>di</strong>sruptions.<br />

Plasma theory progressed along the tra<strong>di</strong>tional lines of Frascati theory team. Beta induced Alfven eigenmodes (BAE),<br />

observed on FTU during the first part of islands growth, were found to agree with theoretical pre<strong>di</strong>ctions for sufficiently<br />

low magnetic island amplitudes, consistently with perturbative theory. Significant efforts have been devoted to analysing<br />

nonlinear behaviours in burning plasmas of fusion interest, their complex dynamics and the issues that arise when<br />

modelling these phenomena with increasingly more realistic physics and equilibrium descriptions. Many of these<br />

theoretical activities significantly contributed to advancing the FAST conceptual design; the activities specifically carried<br />

out within the framework of this project are summarized in the specific FAST section.<br />

Being JET operations suspended for the installation of the new ITER like wall (ILW), <strong>ENEA</strong> scientists have focused their<br />

activity in the analysis of the data gathered during last campaigns and finalized journal papers and contribution to<br />

international conferences, such as EPS, SOFT, IAEA and others. They also actively participated in the elaboration of the<br />

JET programme for 2011


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

011<br />

1.1 FTU Facility<br />

Summary of the machine operation<br />

The first experimental campaign started at the end of March but it was imme<strong>di</strong>ately stopped due to a leak<br />

in the vacuum chamber. After that a long series of vacuum problems prevented operations from being<br />

restarted until mid–June. The experimental campaign went on until the end of June, when it was closed due<br />

to problems to the motor flywheel generator (MFG1) chiller.<br />

The restart of the machine, originally scheduled for the end of October, began mid November, but,<br />

unfortunately, the 141 pulses done (51 of which for plant tests) turned out to be useless for the experimental<br />

campaign, because of several hardware failures. The main problem encountered was a broken electronic card<br />

of the Programmable High Speed Controller (PHSC) which controls the poloidal power supplies: since it<br />

required long time for reparation, this led to the end of the experimental campaign.<br />

Therefore, the statistics considered for 2010 are those of the first experimental campaign: 320 shots were<br />

successfully completed, out of a total of 349 performed in 12.5 experimental days. The average number of<br />

successful daily pulses was 25.60. Table 1.I reports the summary data. Figure 1.1 reports the source of<br />

downtime in 2010: Power Supplies is the greatest cause of delay with 31% of the total.<br />

Control and Data Acquisition System. The project of replacing ageing hardware on Frascati Tokamak<br />

Upgrade (FTU) and improving the software infrastructure in the control and data acquisition area, is still<br />

under way. It is mainly based on the principles of the open source software and commo<strong>di</strong>ty hardware.<br />

The physical link between the lower and the me<strong>di</strong>um level in the FTU<br />

control system three–level standard model – historically relying on<br />

RS232 protocol on fiber optics – was replaced with serial<br />

communication on standard Ethernet by using a new device<br />

which provides network access to industrial instruments through<br />

a serial connection. The technology has also allowed de<strong>di</strong>cated<br />

hardware to be replaced by using machine virtualization on a<br />

single Linux host.<br />

A high multiplexed channel density and few kHz lower hybrid<br />

(LH) power data acquisition systems were developed in<br />

Compact PCI standard. Moreover, the legacy Soft–X VME<br />

data acquisition system CPU was renewed by developing at the<br />

same time a new software interface based on open source<br />

Universe II libraries, and a more user friendly management<br />

system.<br />

Figure 1.1 – Source of downtime in 2010.<br />

Power supplies is the greatest cause of delay<br />

with 31% of the total


012<br />

progress report<br />

2010<br />

Table 1.I – Summary of FTU operations in 2010<br />

Jan. Feb. March April May June July Total<br />

Total pulses (p) 11 0 0 22 0 283 33 349<br />

Successful pulses (sp) 9 0 0 19 0 262 30 320<br />

I(sp) 0.82 0.86 0.93 0.91 0.92<br />

Potential experimental days 3.5 0.0 3.5 0.0 10.0 6.0 23.0<br />

Real experimental days 0.5 0.0 1.0 0.0 10.0 1.0 12.5<br />

I(ed) 0.14 0.29 1.00 0.17 0.54<br />

Experimental minutes 134 0 287 0 4476 500 5397<br />

Delay minutes 119 0 345 0 1735 155 2354<br />

I(et) 0.53 0.45 0.72 0.76 0.70<br />

A(sp/d) 18.00 19.00 26.20 30.00 25.60<br />

A(p/d) 22.00 22.00 28.30 33.00 27.92<br />

Delay per system (minutes)<br />

Jan. Feb. MarchApril May June July Total %<br />

Machine 94 0 0 12 0 339 42 487 20.7<br />

Power supplies 10 0 0 83 0 599 33 725 30.8<br />

Ra<strong>di</strong>ofrequency 0 0 0 0 0 0 0 0 0.0<br />

Control system 0 0 0 0 0 108 0 108 4.6<br />

DAS 0 0 0 0 0 44 0 44 1.9<br />

Feedback 0 0 0 0 0 84 0 84 3.6<br />

Network 0 0 0 0 0 0 0 0 0.0<br />

Diagnostic systems 0 0 0 39 0 115 30 184 7.8<br />

Analysis 12 0 0 0 0 283 50 345 14.7<br />

Others 3 0 0 211 0 163 0 377 16.0<br />

TOTAL 119 0 0 345 0 1735 155 2354 100<br />

An upgrade of the present FTU feedback control system was started, also envisaging a possible reutilization<br />

in the proposed FAST experiment. A pre–existent framework called multithreaded application real–time<br />

executor (MARTe), already successfully used in other European tokamak devices, was adopted. MARTe has<br />

been integrated in the current control structure and pulse programming interface, thus provi<strong>di</strong>ng a common<br />

environment with other MARTe systems already running in FTU, such as the real time version of the plasma<br />

equilibrium reconstruction RT–ODIN and the satellite station that minimizes the LH reflected power.<br />

50<br />

40<br />

30<br />

20<br />

10<br />

0<br />

Figure 1.2 – 2010 ITM–TF users grouped by country<br />

F D I UK FINCH PL P S EU A CZ GR NL B DK RO CY E H IRLRUSLO US NaN<br />

ITM Task Force Gateway. The<br />

Gateway operations have continued to<br />

provide the full scale support to<br />

Integrated Tokamak Modelling–Task<br />

Force (ITM–TF) users, thus allowing<br />

them to develop ITM software and<br />

data access facilities. It has been<br />

carried out by means of the Gateway<br />

trouble ticket system and <strong>di</strong>rect<br />

support by email.<br />

A number of 223 ITM–TF users have<br />

got an account onto the Gateway in<br />

2010 as depicted in figure 1.2. The<br />

development & testing activity of the<br />

ITM–TF users is reported as CPUs


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

013<br />

% CPU usage<br />

100<br />

EFDA-ITM batch cluster yearly usage<br />

0<br />

Jan 01 Mar 01 May 01 Jul 01 Sept 01 Nov 01<br />

Total CPU load % Current: 2% Average: 9% Maximal: 100%<br />

Figure 1.3 – CPUs yearly usage of the<br />

Gateway batch cluster<br />

yearly usage of the Gateway batch cluster in 2010 and shown in figure 1.3. The upgrade activity has been<br />

carried out involving the base software (operating system, parallel filesystem, <strong>di</strong>stributed filesystem) and<br />

scientific tools as well.<br />

The Storage Data Area used in 2010 is as follow: 4.3 TB for users and software repositories stored under the<br />

<strong>di</strong>stributed filesystem, 14 TB for simulation data stored under the parallel filesystem.<br />

The RAM resources of Front–End nodes have been updated to 32 GB for each one, to take into account the<br />

heavy CPU usage due to the interactive sessions during Code Camp meeting.<br />

Several EU Code Camp 2010 meetings were supported by using hardware/software resources of the Gateway.<br />

The Inter–operability between ITM Gateway and High Performance Computing For Fusion (HPC–FF) has<br />

been implemented fully. It allows both HPC facilities to be used in a common operating environment for<br />

sharing codes, data exchange and user access, as well as joint tools and libraries to facilitate the creation of<br />

community fusion codes.<br />

1.2 FTU Experimental Activity<br />

Lower hybrid<br />

Lower hybrid current drive experiments in plasma regimes of interest for ITER. The need for non–ohmic<br />

steady–state current drive is a fundamental weakness of the tokamak as a magnetic fusion reactor. Low<br />

frequency microwaves, in the range of a few GHz, have been successfully used to drive current in tokamak<br />

core plasmas at relatively low densities [1.1–1.3], but extrapolation of these results to the higher densities of<br />

ITER and subsequent reactor grade plasmas has proved to be problematic, because the coupled LH power<br />

stubbornly localizes in the plasma edge region [1.4,1.5].<br />

A thermonuclear plant needs to maximise the bootstrap current for saving current driven by external power<br />

sources. For this reason ITER will need to operate with almost flat ra<strong>di</strong>al profiles such that high pressure<br />

gra<strong>di</strong>ent occur in the external region of the plasma column with high densities even at the edge (at normalized<br />

minor ra<strong>di</strong>us r/r LCMS<br />

∼0.9: n e_0.9<br />

≥0.7×10 20 m –3 , and in the centre: n e0<br />

≥0.8×10 20 m –3 , where r LCMS<br />

is the<br />

plasma minor ra<strong>di</strong>us at the last closed magnetic field surface (LCMS)). The operation with relatively high<br />

plasma density in the region of the periphery is thus an important constraint to be considered for designing a<br />

tool for driving actively non–inductive current in the plasma, which is essential for obtaining the necessary<br />

requirements of stability and confinement.<br />

Theoretical and experimental works have been extensively carried out on FTU, which have evidenced the role<br />

of parametric instabilities (PI) in inhibiting penetration of the lower hybrid wave to the plasma core when<br />

operating at relatively high plasma densities [1.4,1.5]. These works have produced the guidelines used in the<br />

FTU experiments, based on theoretical pre<strong>di</strong>ctions that the PI–produced spectral broadening would <strong>di</strong>minish<br />

under operations with higher electron temperatures at the periphery (T e_outer<br />

) of the plasma column [1.3]. As<br />

a result of operating in such a regime, the spectral broadening measured by ra<strong>di</strong>o–frequency (rf) probe has<br />

been indeed observed to <strong>di</strong>minish. It has also been observed that the LH power penetration into a high density<br />

core took place as expected.<br />

The following options, available on the FTU device, have been exploited for producing <strong>di</strong>fferent plasma edge<br />

temperatures in high–density plasmas, and <strong>di</strong>fferent plasma targets for LH power coupling: i) Toroidal or<br />

poloidal limiter operations. With toroidal limiter operations, a stronger plasma–wall interaction occurs due to<br />

the larger plasma–wall contact area. In these con<strong>di</strong>tions lower recycling of particles from the vessel walls and


014<br />

progress report<br />

2010<br />

relatively low temperature at the plasma periphery generally occur. Conversely, in operations with the plasma<br />

<strong>di</strong>splaced towards the poloidal limiter, the D–alpha emission level is about ten times smaller, and slightly higher<br />

electron temperatures are observed at the plasma edge than in similar experiments using the toroidal limiter.<br />

ii) Vacuum vessel covered with boron or lithium. With lithium, sprayed on the walls from the limiter, where it<br />

is present in liquid form (because of the liquid lithium limiter (LLL) available in FTU), a level of recycling<br />

significantly lower than with a boron–coated vessel is produced. iii) Plasma fuelling assisted by pellet injection.<br />

FTU has a pneumatic single stage multibarrel pellet injector, capable of firing up to eight pellets per plasma<br />

<strong>di</strong>scharge with a typical velocity of 1.3 km/s and a mass of the order of 10 20 deuterium atoms. As critical<br />

aspects of the pellet technique, in order to achieve a deep plasma core fuelling for producing high electron<br />

temperature at the plasma periphery, proper velocity and mass of pellets should be set. In ad<strong>di</strong>tion, the LH<br />

power switch-on time point should occur with some delay (of the order of 10 ms) as compared to the pellet<br />

injection, in order to prevent the ablation of pellet by the coupled rf power. iv) In order to further reduce the<br />

recycling, the technique of extra–gas fuelling in the early <strong>di</strong>scharge phase has been used. In the standard gas<br />

fuelling technique, the requested density value at the start of the lower hybrid current drive (LHCD) pulse is<br />

set by the plasma density feedback control, which generally produces a continuous gas injection during the<br />

whole plasma <strong>di</strong>scharge. Relatively high levels of recycling and low temperatures at the plasma periphery were<br />

obtained on FTU with this operation. In the technique of extra-gas fuelling in the early <strong>di</strong>scharge phase a<br />

large amount of gas should be injected in the early <strong>di</strong>scharge phase (but already during the plasma current<br />

flat–top), which transiently produces a plasma density slightly higher than the value required for the LHCD<br />

pulse. The density then falls to the required value after a delay during which a pause in the gas injection is<br />

programmed, so that low recycling occurs. By firing pellets during the gas injection pause, plasmas with very<br />

high–density and low recycling should be produced.<br />

The experiments results shown in ref. [1.4] have produced con<strong>di</strong>tions for LH current drive that are transient,<br />

and the extrapolation of the method obtained to stead–state regime would appear problematic. Further data<br />

of the FTU experiment obtained in 2009 support the conclusion that a relatively high electron temperature at<br />

the periphery of the plasma column, produced with tools useful for maintaining the edge plasma con<strong>di</strong>tions<br />

in steady–state, has the effect of reducing the spectral broadening of the signal as measured by rf probe and<br />

enhancing the hard–x ray emission from LH–generated fast electrons, i.e., the LHCD occurring in the core.<br />

Plasma <strong>di</strong>scharges have been produced with similar density profiles at me<strong>di</strong>um values of density<br />

(n e_av<br />

∼0.8×10 20 m –3 ), keeping the same ra<strong>di</strong>al profile, but with <strong>di</strong>fferent electron temperature at the plasma<br />

periphery. The behaviour of the spectral broadening measured by rf probe during FTU experiments<br />

performed in similar operating con<strong>di</strong>tions but <strong>di</strong>fferent temperatures at the edge is shown in the figure 1.4.<br />

The new important information obtained by the FTU results is that higher electron temperatures at the<br />

plasma periphery favour the occurrence of LHCD effect in the core also in case without pellet injection and<br />

during the whole phase of LH power coupling. This circumstance support the hypothesis that LHCD effects<br />

can be produced and sustained also in steady–state at high densities provided that suitable con<strong>di</strong>tions of high<br />

temperatures at the edge should be maintained by means of an active tool of local plasma heating, provided<br />

by electron cyclotron resonant heating (ECRH). Available<br />

data from simulations show that the LHCD effect, already<br />

=0.57×10 20 m –3<br />

14 obtained during the transient phase of pellet fuelling of<br />

1×10 4<br />

=0.8×10 20 m –3<br />

FTU plasmas, should be further sustained in steady-state<br />

con<strong>di</strong>tion by utilising ECRH power.<br />

LH–hard X (counts/s)<br />

1.2×10 4<br />

8000<br />

4000<br />

0<br />

0.2 0.3 0.4 0.5<br />

T e–edge (@ r/a=0.7) KeV<br />

10<br />

6<br />

Δf(@–35 dB MHz)<br />

Figure 1.4 – Hard–x ray level (curve in red) produced<br />

by LH–accelerated electrons and line frequency<br />

spectral broadening (curve in blue) plotted versus<br />

the electron temperature at normalised minor ra<strong>di</strong>us<br />

r/a=0.7, for FTU <strong>di</strong>scharges with same plasma<br />

density profiles and coupled LH power (0.35 MW)<br />

Revision of the LHCD system for ITER. In the frame of<br />

the European Fusion Development Agreement (EFDA)<br />

task WP08–HCD–03–01 "LH4IT" (WP VI–2–1): EU<br />

Contribution to the ITER LHCD Development Plan, the<br />

conceptual design of the LHCD system for ITER,<br />

elaborated in the years 2001–2002, has been revised by<br />

taking into account all the physical and technological<br />

progresses and innovations.<br />

Experimental results obtained in the last few years, such as<br />

the successful tests of a passive–active multijunction (PAM)<br />

launcher on FTU and Tore Supra, have definitely in<strong>di</strong>cated<br />

this concept as a possible can<strong>di</strong>date for the LHCD launcher<br />

for ITER. The successful development of a prototype


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

015<br />

klystron at 5 GHz with a target rf power of 500 kW continuous wave (CW) has definitely set this power as the<br />

upper limit to the present high vacuum electron tubes technology at this frequency. From the physics point of<br />

view, the ITER operational scenarios have been well defined, while the latest experiments have pointed out the<br />

effectiveness of the LHCD waves at high plasma density.<br />

Following the recommendations of the 4th meeting (19–22 May 2008) of the ITER STAC, the assigned<br />

objectives of the task were "to perform the conceptual design and to initiate the urgent R&D activities in order<br />

to bring the ITER LHCD system up to the point at which such activities could be transferred to the Fusion<br />

For Energy (F4E)".<br />

The "LH4IT" task has been performed in close collaboration between <strong>ENEA</strong> – Frascati and Commissariat à<br />

l’Energie Atomique (CEA) – Cadarache as well as with ITER Organization (IO) and several other ITER<br />

partners.<br />

A 5 GHz prototype klystron (fig. 1.5) developed by Toshiba for the LHCD system of the Korean tokamak<br />

KSTAR has demonstrated a CW output power of 350 kW, a 10s pulsed power of 455 kW, and a peak power<br />

of 510 kW for 0.5 s.<br />

These promising results confirm the possibility of realizing a 500 kW CW klystron with an operational<br />

frequency of 5 GHz in a relatively short time. On the other hand these results also demonstrate the 500 kW<br />

as the upper power limit for klystrons in this range of frequency. The required 20 MW of rf power coupled<br />

to the plasma can be therefore obtained by 48 500 kW klystrons. Each klystron feeds a PAM module (fig. 1.6)<br />

made of six toroidal rows and four toroidal columns of elemental alternated<br />

active/passive waveguides. To launch an optimum rf spectrum with N 0<br />

=1.9 with<br />

a phase shift of 270° between active waveguides, the active waveguide width is set<br />

to 10 mm, with a passive waveguide width of 8mm and separation wall thickness<br />

of 3 mm at the launcher mouth.<br />

The rf power of each klystron is carried by moderately oversized circular<br />

waveguides (the C 16 standard with inner ra<strong>di</strong>us R=67.05 mm) which transmit the<br />

TE 01<br />

circular mode. The correspon<strong>di</strong>ng evaluated transmission losses are about<br />

0.22 dB/100 m.<br />

Suitable mode filters (fig. 1.7) have been taken into consideration and stu<strong>di</strong>ed in<br />

order to suppress potentially detrimental spurious modes generated by the four 45<br />

deg and one 100 deg bends included in the main transmission lines (MTLs). These<br />

filters are based on the attenuation introduced by the perio<strong>di</strong>c corrugation of the<br />

waveguide wall, enhanced by the presence of absorbing material silicon carbide<br />

Active<br />

waveguide<br />

1st BJ<br />

Figure 1.6 – Schematic drawing of a PAM module<br />

Figure 1.5 – The<br />

500 kW prototype<br />

klystron<br />

2nd BJs<br />

d<br />

a<br />

400 mm<br />

Base circular waveguide<br />

P<br />

Corrugations<br />

SiC<br />

100 mm<br />

Passive<br />

waveguide<br />

Figure 1.7 – Longitu<strong>di</strong>nal cut of a corrugated mode<br />

filter in circular waveguide


016<br />

progress report<br />

2010<br />

Ceramic<br />

window<br />

Input WR284<br />

(72.14 x 34.04 mm)<br />

Reference plane<br />

position<br />

Short circuit<br />

WR 284<br />

Figure 1.8 – Pillbox ceramic window<br />

Output<br />

(58 x 34.04 mm)<br />

Figure 1.9 – The 3dB hybrid junction<br />

Figura 1.10 – Electric field in the<br />

TE 10 to TE 30 mode converter<br />

(SiC), on the TE mn<br />

modes (m≠0). The<br />

propagation of TE 0n<br />

modes with n>1 is<br />

avoided by an accurate <strong>di</strong>mensioning of the<br />

base waveguide <strong>di</strong>ameter.<br />

In the following figures the most critical microwave components of the transmission system are shown, as, e.g.,<br />

the 500 kW, CW pillbox ceramic window (fig. 1.8) separating the pressurized MTL from the vacuum region<br />

of the launcher; the 3 dB hybrid junction (fig. 1.9) to initially split by two the rf power generated by each single<br />

klystron; the TE 10<br />

to TE 30<br />

mode converter (fig. 1.10), which splits into three each output branch of the<br />

previous hybrid junction in order to suitably feed the upper and lower parts of a single PAM module. The final<br />

power <strong>di</strong>stribution among the four active waveguides of each row of a PAM module is obtained by classical<br />

cascaded bijunctions.<br />

Alfvén Eigenmodes: modeling, experimental results and future plans<br />

Electron–fishbones stu<strong>di</strong>es. Electron–fishbones are internal kink mode instabilities induced by supra–thermal<br />

electrons. The knowledge of the supra–thermal electron dynamics, in presence of fishbone fluctuations, is very<br />

important in burning plasmas. Indeed, energetic particles in the MeV range are present in ignited plasmas, as<br />

either fusion products (alpha particles) or supra–thermal tails induced by ad<strong>di</strong>tional heating systems. In<br />

particular, good confinement and slowing down of alpha particles (electron collisional heating) are very<br />

important issues. Perpen<strong>di</strong>cular transport of magnetically trapped supra–thermal electrons is similar to that<br />

of fusion alphas, since both have small orbit as compared to the plasma minor ra<strong>di</strong>us. Thus, the investigation<br />

of such dynamics may shed new light on physics issues related to alpha particles. The stability analysis of<br />

e–fishbones can be carried out within the framework of the so called general fishbone–like <strong>di</strong>spersion relation,<br />

which can be thought of as a kinetic energy principle. Previous experiments on e–fishbone in FTU have been<br />

conducted with lower hybrid ra<strong>di</strong>o frequency heating and q min<br />

>>1. They suggest that the level of the rf power<br />

determines the energy content of the supra–thermal electron tail and is crucial in controlling the transition<br />

from nearly steady state non–linear oscillations to bursting regime; moreover, experimental observations<br />

confirm the theoretical conjecture that the e–fishbone in the bursting regime is a continuum resonant mode<br />

[1.6]. FTU experiments, as well as experiments conducted at Tore–Supra [1.7], underline the necessity of<br />

systematic comparisons between experiments and theory by means of the general fishbone–like <strong>di</strong>spersion<br />

relation and appropriate simulations codes. MARS is a resistive–magnetohydrodynamic (MHD) stability code<br />

that can be used to this purpose to calculate the part of the plasma response entering the fishbone–like<br />

<strong>di</strong>spersion relation, i.e. the MHD potential energy contribution. With this information, systematic stability<br />

stu<strong>di</strong>es are underway, which can give insights about the FTU plasma con<strong>di</strong>tions where the kinetic response due<br />

to supra–thermal electron tails is most likely to yield the fishbone instability. In particular, q–profile sensitivity<br />

stu<strong>di</strong>es will be carried out as well, for they will clarify the role of current profile in the e –fishbone dynamics.


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

017<br />

Experimental observation of beta–induced Alfvén Eigenmodes.<br />

FTU activities in 2010 were focused on the observation of long<br />

(>200 ms) beta–induced Alfvén eigenmodes (BAEs), which are<br />

high frequency oscillations (30–70 kHz) in tokamak plasmas,<br />

identified in the spectrum of the Alfvénic modes as <strong>di</strong>screte<br />

eigenmodes located in the low frequency gap of the Alfvén<br />

continuum produced by the geodesic curvature and finite beta<br />

effect. BAEs have been first identified as waves excited by<br />

circulating fast ions, however they were also observed in ohmic<br />

plasmas with the simultaneous presence of large magnetic islands<br />

[1.8]. BAE oscillations from 30 to 50 KHz have been observed in<br />

FTU plasmas with the simultaneous occurrence of tearing modes<br />

(characterized by frequencies from 1 to 5 KHz). BAEs have<br />

intensities two order of magnitude less than tearing modes, and<br />

are characterized by two main lines, which merge in a single line<br />

when the island oscillation frequency becomes very low. Mode<br />

analysis for tearing mode shows that poloidal and toroidal mode<br />

numbers are (m, n)=(–2,–1). On the other side, the higher BAE<br />

frequency is characterized by (m, n)=(–2,–1), i.e., propagates in<br />

the same <strong>di</strong>rection as the island, while the lower BAE frequency<br />

has (m, n)=(2,1), i.e., propagates in the opposite <strong>di</strong>rection. The<br />

<strong>di</strong>fference in frequency of the two BAE lines is exactly twice the<br />

fundamental frequency of the tearing mode, and the frequency<br />

<strong>di</strong>fference can be explained by the doppler shift due to island<br />

rotation.<br />

In the following figure 1.11 the comparison between the<br />

theoretical pre<strong>di</strong>ction [1.9] of BAE frequency as a function of<br />

magnetic island amplitude δB r<br />

/B p<br />

and the experimental<br />

observations is shown. During the first part of the island growth,<br />

BAE frequency increases roughly linearly, in good agreement<br />

with theoretical pre<strong>di</strong>ctions; on the other hand, a <strong>di</strong>screpancy is<br />

found for δB r<br />

/B p<br />

>2 ×10 –3 where BAE frequency remains rather<br />

constant. Therefore, we can state that, as expected, the<br />

perturbative theory used gives consistent results only for<br />

sufficiently low magnetic island amplitudes.<br />

BAE frequency (kHZ)<br />

55<br />

45<br />

Observed frequency (N 23184)<br />

Observed frequency (N 26644)<br />

Observed frequency (N 25877)<br />

Pre<strong>di</strong>cted frequency (N 23184)<br />

Pre<strong>di</strong>cted frequency (N 26644)<br />

Pre<strong>di</strong>cted frequency (N 25877)<br />

35<br />

0.5 1.5 2.5 3.5 4.5 ×10 -3<br />

δBr(rs)/Bp(rs)<br />

Figure 1.11 – BAE frequency as a function of<br />

magnetic island amplitude δB r /B p (curves<br />

are the theoretical pre<strong>di</strong>ctions and markers<br />

are the experimental points)<br />

(V)<br />

T e (keV)<br />

n/s<br />

Counts<br />

Energy (MeV)<br />

1.5<br />

0.5<br />

0.5<br />

0<br />

4<br />

2<br />

0<br />

10 11<br />

10 10<br />

10 3<br />

10 2<br />

8<br />

4<br />

Experimental V I<br />

Collisional threshold<br />

NE213<br />

BF 3<br />

a)<br />

b)<br />

c)<br />

Total γ - counts<br />

#22472<br />

0<br />

0 0.4 0.8 1.2<br />

Time (s)<br />

d)<br />

e)<br />

Electron cyclotron<br />

Runaway electrons in FTU. Runaway electrons constitute a<br />

well–known phenomenon in tokamaks: due to the decrease in the<br />

Coulomb collision frequency with energy, electrons with energy<br />

larger than some critical value are continuously accelerated by<br />

the toroidal electric field. Calculations inclu<strong>di</strong>ng relativistic effects<br />

in<strong>di</strong>cate that below a critical or threshold electric field,<br />

E R<br />

=(n e<br />

e 3 lnΛ)/(4πε 0<br />

m e<br />

c 2 ) absolutely no runaway electrons are<br />

produced [1.10]. Experiments carried out in FTU show that<br />

Figure 1.12 – Runaway suppression in<br />

<strong>di</strong>scharge 22472: a) loop voltage; b) electron<br />

temperature (the ECRH time window is<br />

represented by the shaded area); c)<br />

comparison between neutrons (BF 3 ) and<br />

gamma & neutron detectors (NE213): when<br />

the two signals coincide runaways are<br />

suppressed; d) total counts and e) maximum<br />

measured energy from γ–ray NaI<br />

spectrometer<br />

synchrotron ra<strong>di</strong>ation losses should also be taken into account, since they lead to an increase in the critical<br />

electric field. These results are important when making pre<strong>di</strong>ctions on runaway generation and mitigation<br />

during <strong>di</strong>sruptions in next–step devices such as ITER.<br />

Suppression of runaway electrons has been achieved in FTU (fig. 1.12) by application of ECRH) during the<br />

flat–top phase of the <strong>di</strong>scharge, at electric field values substantially larger (by a factor ∼2) than the pre<strong>di</strong>cted<br />

collisional threshold field, E R<br />

∼0.09 n e<br />

(10 20 m –3 ). The parameters used in the experiments are the following:<br />

I p<br />

=0.3–0.5 MA, B t<br />

=4–6 T, central line averaged density n e<br />

=4–8×10 19 m –3 and electron cyclotron (140 GHz)<br />

input power P ECRH<br />

= 0.3–1 MW. The interpretation of these observations, based on calculations inclu<strong>di</strong>ng the<br />

electron synchrotron (ra<strong>di</strong>ation) term (fig 1.13) leads to the conclusion that the ra<strong>di</strong>ation losses are responsible


018<br />

progress report<br />

2010<br />

dW/dt (Arb. units)<br />

6<br />

5<br />

4<br />

3<br />

2<br />

Collision stopping power<br />

Ra<strong>di</strong>ative stopping power<br />

Total stopping power<br />

eE R<br />

rad νII<br />

e E II ν II<br />

1<br />

W c1<br />

W c2<br />

0<br />

0 1 2 3 4 5<br />

Energy (MeV)<br />

Figure 1.13 – Collision, ra<strong>di</strong>ation, and total stopping<br />

powers for an electron. For an energy gain below<br />

(eE ν ) no runaways can be found. Electrons with<br />

energies W c1


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

019<br />

(see fig.1.15, blue symbols). Moreover we observe that, at high ν eff<br />

values, a well detectable delay between<br />

density and temperature rise (re)appears.<br />

The interaction between ITER like plasmas and the EC heating have to be investigated also under the profile<br />

of the effect of the heating system on the particle–energy confinement time with de<strong>di</strong>cated experiments<br />

extended to H–mode regimes and in conjunction with <strong>di</strong>fferent heating systems.<br />

Sawteeth (de)stabilization by ECH and ECCD in FTU. In FTU the destabilization of sawteeth (ST) has been<br />

investigated using ECH and electron cyclotron current drive (ECCD) as a powerful tool for the shortening of<br />

ST period τ saw<br />

. This is a critical issue for the plasma confinement in fusion devices. In fact, long–period<br />

sawteeth give rise to large crashes that can trigger seed islands, thus destabilizing neoclassical tearing modes<br />

(NTM) that, on turn, degrade the plasma performances at high β. This programme was included in the work<br />

plan of the International Tokamak Physical Activity (ITPA) MHD working group on ST control for the<br />

empirical scaling of power requirement for avoi<strong>di</strong>ng the onset of NTMs. The sawteeth crash induced by ECH<br />

and co–ECCD was performed by using 500 ms of<br />

repetitive pulses (10 ms EC on, 40 ms EC off) from two<br />

12<br />

8 ×10 5<br />

gyrotrons, up 0.8 MW total power.<br />

As the ST crash happens when the local magnetic<br />

shear s=rq’/q exceeds a critical value,<br />

ECH/co–ECCD, increasing the current density inside<br />

the inversion ra<strong>di</strong>us (q=1), can shorten the ST period<br />

by sharpening the q profile and enhancing the local<br />

shear. ST destabilization has been performed in<br />

plasmas at 500 kA with toroidal field ramping from 5.1<br />

to 5.9 T in order to scan the EC absorption ra<strong>di</strong>us r abs<br />

from the plasma centre to well outside the q=1 ra<strong>di</strong>us<br />

and find the magnetic field value at which the sawteeth<br />

crash is induced by the EC trigger. Preliminary results<br />

are shown in figure 1.16, where the time delay<br />

t EC,on<br />

– t ST,crash<br />

is plotted during the EC modulation.<br />

For EC absorption inside the q=1 ra<strong>di</strong>us the ST<br />

periods are reduced from 6 ms (ohmic value) to about<br />

2–4 ms, while for EC absorption outside the q=1<br />

(t>0.8 s) the EC power plays an opposite effect, thus<br />

lengthening τ saw<br />

up to 10 ms.<br />

These results show that 0.8 MW of EC power can<br />

destabilize the ST by shortening their periods when EC<br />

absorption occurs inside the q=1 ra<strong>di</strong>us, where the<br />

ECH/co–ECCD increase the magnetic shear thus<br />

inducing the sawteeth crash. The next experiments<br />

should be devoted to investigating the EC power<br />

threshold for destabilization.<br />

Tests of the new ECRH launcher for FTU. The new<br />

EC antenna for real time control experiment on FTU<br />

tokamak was tested at the Istituto <strong>di</strong> Fisica del Plasma<br />

(IFP)–Consiglio Nazionale Ricerche (CNR) – Milano<br />

at the beginning of 2010. A series of tests concerning<br />

specific design issues and the launcher assembly were<br />

performed in order to validate the technical solutions<br />

adopted and to characterize the antenna in its final<br />

configuration, with low power measurements. A test<br />

facility was installed for the launcher tests (fig. 1.17).<br />

The mechanical tests involved the cardanic joints of<br />

the driving system, based on rotational movements,<br />

which are transferred, via vacuum–compatible<br />

rabs/rinv τsaw(ms) B t (T)<br />

10<br />

8<br />

6<br />

6 ×10 5<br />

4 ×10 5<br />

4<br />

2 ×10 5<br />

2<br />

q=1<br />

0<br />

0<br />

0.5 0.6 0.7 0.8 0.9 1<br />

Time (s)<br />

ECRH<br />

Figure 1.16 – Combined effects of ECH/co–ECCD on τ saw<br />

(green circles) in the <strong>di</strong>scharge with ramped B t (black<br />

solid line). For B t > 5.4 T the absorption is outside q=1<br />

and the ST periods are greater than the ohmic ones<br />

(dashed line). The ratio between the EC power<br />

absorption minor ra<strong>di</strong>us rabs and the inversion ra<strong>di</strong>us is<br />

also marked (red line) during the 500 ms EC power<br />

modulation (10 ms on/40 ms off, blue line)<br />

Figure 1.17 – Experimental setup used to test the plug-in<br />

launcher at IFP mm-wave laboratory. The two launching<br />

lines (symmetric as to the equatorial plane) are visible<br />

and the low power mm–wave source can be seen on the<br />

top left


020<br />

progress report<br />

2010<br />

Power<br />

(Linear amplitude)<br />

Power<br />

(Linear amplitude)<br />

1.0<br />

0.8<br />

0.4<br />

0<br />

1.0<br />

0.8<br />

0.4<br />

0<br />

W tor =18.0 mm d in =800 mm<br />

W tor =20.8 mm d in =700 mm<br />

W tor =24.5 mm d in =600 mm<br />

a)<br />

-20 0 20 60<br />

Probe position (mm)<br />

ν pol =19.2 mm d in =800 mm<br />

ν pol =22.1 mm d in =700 mm<br />

ν pol =27.6 mm d in =600 mm<br />

b)<br />

0 20 40 60 80<br />

Probe position (mm)<br />

Figure 1.18 – Output beam profiles in the toroidal a) and poloidal b) <strong>di</strong>rection,<br />

obtained with the upper antenna (W is the beam ra<strong>di</strong>us in the toroidal and poloidal<br />

<strong>di</strong>rection, respectively; d in is the input <strong>di</strong>stance between the input beam waist and<br />

the focusing mirror). Dots correspond to the acquired data, curves to the Gaussian<br />

fit of the beam profile<br />

Vertical probe position (mm)<br />

80<br />

60<br />

40<br />

20<br />

0<br />

Power (dB) - angles: α=0°, β=0°<br />

Speed ref.<br />

motor 2<br />

Speed ref.<br />

motor 1<br />

MIRROR POSITION CONTROLLER<br />

(with real–time plasma ray tracing)<br />

Plasma<br />

feedback<br />

-20 0 20 20 60<br />

Horizontal probe position (mm)<br />

Figure 1.19 – Beam amplitude pattern (dB) obtained from<br />

the upper antenna set in the reference configuration:<br />

contour levels are shown, where the –8.7 dB level<br />

corresponds to the definition of beam ra<strong>di</strong>us w<br />

PROTECTION SYSTEMS<br />

Alarm<br />

MOTOR 1 + DRIVE<br />

(speed and torque controller)<br />

MOTOR 2 + DRIVE<br />

(speed and torque controller)<br />

Position<br />

motor 1<br />

Position<br />

motor 2<br />

Figure 1.20 – Scheme of mirror control and<br />

protection systems<br />

coupling rods, to the external motors, put at the rear of<br />

the port. After these tests, a revision of the joints design<br />

was necessary. The new solution ensured better results in<br />

terms of the overall performances and reliability in the<br />

mechanical transmission of the movement, from the<br />

motor to the steering mirror unit.<br />

Low power tests were carried out after an optical<br />

alignment of the antenna, performed by using a laser<br />

mounted outside the port flange with beam aligned with<br />

the microwave beam axis and markers used to check the laser spot position on each mirror of the beam line.<br />

The tests have been made by using a 140 GHz horn–mirror antenna to launch a Gaussian beam matching a<br />

field close to the one measured at the aperture of the FTU transmission line. A vector network analyzer (VNA)<br />

was used to perform the tests, with a receiving antenna made with a properly shielded truncated waveguide.<br />

The upper and lower antennas output beams were measured. The beam zooming effect was verified by<br />

measuring the launched beam <strong>di</strong>mension (fig. 1.18) for <strong>di</strong>fferent positions of the sli<strong>di</strong>ng mounting, and<br />

comparing them with the expected values. Also 2–D beam pattern measurements and 1–D scans were<br />

acquired, to evaluate the <strong>di</strong>ffraction effects (fig. 1.19).<br />

The functionality of the brushless motors chosen for the last steering mirror movement, was tested in presence<br />

of an external magnetic field (B MAX<br />

=0.1 T) estimated at the location foreseen for the motors in the FTU hall,<br />

in real con<strong>di</strong>tions of typical plasma operations. A 3–D model provides maps of the local value of the stray<br />

field surroun<strong>di</strong>ng FTU during the shot (fig. 1.20). Such a model gave a maximum of ≈0.058 T for the stray<br />

magnetic field expected at the motors location during typical plasma <strong>di</strong>scharges. A permanent magnetic field<br />

source, able to produce 0.1 T as a maximum field in correspondence of the poles and 0.05 T in the air gap,<br />

was used for dynamical tests: they confirmed that such an external stray magnetic field does not affect the<br />

correct operations of either the brushless motors or the resolver system.<br />

The control and protection systems (shown in fig. 1.20 for one mirror) were tested in order to identify the<br />

parameters of the drive and the mechanical system. Several tests have been repeated with this open-loop<br />

configuration, with and without any mechanical load. In particular, the tests aimed to acquire the system step<br />

response, so the speed reference input was a step with finite length; <strong>di</strong>fferent step amplitudes have been used<br />

to test the linearity of the system (fig. 1.21). The responses obtained showed that the non–linearity is not


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

021<br />

relevant. Simulation results, together with the speed controller<br />

response verified experimentally, seem to confirm that the<br />

target specifications can be achieved.<br />

Liquid lithium experiments<br />

Pellet injection in lithized wall <strong>di</strong>scharges. High density<br />

<strong>di</strong>scharges were obtained through the first successful injections<br />

of D 2<br />

pellets in presence of a significant wall lithization.<br />

Density profiles, for transport analysis, were obtained from the<br />

inversion of the FTU CO 2<br />

scanning interferometer [1.12],<br />

which is a very powerful tool for studying fast evolution of<br />

density profiles and very strong gra<strong>di</strong>ents. Density profiles were<br />

taken every 62.5 μs with a spatial resolution of 1 cm and a line<br />

integrated density resolution Δn¯e/n¯e∼2%. After a prompt<br />

increase in central density, typical of pellet fuelled <strong>di</strong>scharges, a<br />

further peaking is observed following the first pellet, which<br />

suggests the existence of an inward pinch, as seen also in gas<br />

fuelled <strong>di</strong>scharges (figs. 1.22 and 1.23). A fully interpretative<br />

transport analysis of the density profile decay (1st pellet) has<br />

been performed in the region where there are no particle<br />

sources upon completion of pellet ablation (r/a


022<br />

progress report<br />

2010<br />

0.5<br />

#32552, 0.703-0.765 s, r=0.09 m<br />

a)<br />

#32552, 0.703-0.765 s b)<br />

3<br />

D<br />

V<br />

0.3<br />

0.1<br />

2<br />

Γ/n(m/s)<br />

0.1<br />

D(m2/s)<br />

1<br />

V(m/s)<br />

-0.1<br />

0<br />

0<br />

-0.3<br />

0<br />

2 4 6 8 10<br />

d log(n)/dr (1/m)<br />

0<br />

0.05 0.1 0.15<br />

Minor ra<strong>di</strong>us (m)<br />

Figure 1.24 – Experimental particle flux at r=9 cm in the post pellet phase derived from density profiles evolution a). Diffusion<br />

coefficient and pinch velocity versus minor ra<strong>di</strong>us b)<br />

γR ref /c s,D<br />

40<br />

20<br />

0<br />

t=0.3 s,with Li<br />

t=0.3 s,no Li<br />

t=0.8 s,with Li<br />

t=0.8 s,no Li<br />

#30582 r/a=0.6<br />

a)<br />

γRref/cs,D<br />

-0.5<br />

0<br />

20 40<br />

0 0.5 1 1.5 2<br />

k θ ρ D<br />

Figure 1.25 – Growth rates of FTU #30582 at t=0.3 s (crosses) and t=0.8 s (circles). a) ETG modes, b) ITG–TEM modes up to<br />

k θ ρ D =2.0 (here k θ is the wave vector in the θ <strong>di</strong>rection, ρ D is the Larmor ra<strong>di</strong>us of deuterium ions). Results with the same<br />

parameters but without Li impurity are also shown (blue dashed). A concentration of n Li /n e =15% is found to stabilize the ETG<br />

mode, ((a) crosses) and TEM modes ((b) crosses)<br />

2<br />

1<br />

0<br />

t=0.3 s,with Li<br />

t=0.3 s,no Li<br />

t=0.8 s,with Li<br />

t=0.8 s,no Li<br />

k θ ρ D<br />

#30582 r/a=0.6<br />

a)<br />

Linear microstability analysis of lithium doped ohmic plasmas. Improved energy and particle confinement in<br />

the presence of low–Z impurities has been observed in many tokamaks under various experimental con<strong>di</strong>tions.<br />

In particular, peaked electron–density profiles have been obtained in FTU ohmic plasmas where high<br />

concentrations of lithium have been detected following the installation of the LLL. A gyrokinetic study on the<br />

effects of lithium and other low–Z impurities on the linear stability of deuterium and electron temperature<br />

driven modes and their associated fluxes has been carried out for plasma parameters such as those found in<br />

the core of LLL–FTU plasmas. Simulations (fig. 1.25) show that a lithium concentration in excess of<br />

n Li<br />

/n e<br />

=15%, as estimated in the initial phase of a reference FTU <strong>di</strong>scharge, is found to have a strong<br />

stabilizing effect on the trapped electron mode (TEM) and high frequency electron temperature gra<strong>di</strong>ent<br />

(ETG) modes. A significant stabilization of the electron driven modes can still be observed when the lithium<br />

concentration is reduced to 3%. In the presence of a significant impurity concentration (n Li<br />

/n e<br />

=3%–15%) the<br />

long wavelength ion temperature gra<strong>di</strong>ent (ITG) modes drive an inward electron and deuterium flux and<br />

outward lithium flux.<br />

The microstability analysis carried out in<strong>di</strong>cates (fig. 1.26) that, as far as the plasma parameters considered are<br />

concerned, the presence of a lithium concentration of n Li<br />

/n e<br />

=3%–15% in the initial phase of the <strong>di</strong>scharge<br />

is enough to trigger an ITG–TEM driven inward flux of deuterium ions and electrons and an outward flux of<br />

the impurity ions. This dynamics eventually leads to the observed peaked electron density profile and clean<br />

plasma. The <strong>di</strong>fferent sign of the fluxes is due to the phase <strong>di</strong>fference between δn e<br />

, δn i<br />

and δφ allowed by the<br />

presence of the third plasma species (lithium) in the quasi–neutrality con<strong>di</strong>tion.


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

023<br />

×10 -3<br />

4<br />

#30582 r/a=0.6<br />

a)<br />

×10 -3<br />

12<br />

#30582 r/a= 0.6<br />

b)<br />

ΓspRref/(ρ 2 nsp vth,ref)<br />

*<br />

0<br />

−4<br />

−8<br />

ref, D<br />

ref, e −<br />

ref, Li<br />

no Li, D<br />

no Li, e −<br />

0 1 2 3 4 5<br />

k θ<br />

ρ D<br />

ΓspRref/(ρ 2 nsp vth,ref)<br />

*<br />

8<br />

4<br />

0<br />

D<br />

e −<br />

Li<br />

-4<br />

0 1 2 3 4 5<br />

k θ ρ D<br />

Figure 1.26 – Linear E × B particle flux spectrum of the species (red: deuterium, blue: electron, green: lithium) at a) t=0.3 s,<br />

(n Li /n e =15%) and b) t=0.8 s, (n Li /n e =1%) at r/a=0.6. Results with the same physical parameters but without the presence on<br />

lithium impurities are also shown (dashed). The numerical values do not correspond to the saturated flux levels<br />

Diagnostic developments<br />

Electronics equipment for the FTU<br />

bolometry. The bolometric <strong>di</strong>agnostic<br />

installed in FTU measures the total<br />

ra<strong>di</strong>ation losses and the neutral emission<br />

from the plasma, from visible ultraviolet<br />

(VUV) to soft x–rays range. The<br />

bolometer head, developed by<br />

Max–Planck–Institut für Plasmaphysik<br />

(IPP) – Garching, is constituted by two<br />

absorbers, one exposed to the ra<strong>di</strong>ation<br />

and the other one ‘blind’, inserted into a<br />

Wheastone bridge: the rising of<br />

temperature, due the incident ra<strong>di</strong>ation,<br />

causes a variation of the absorber<br />

resistance and, consequently, an<br />

unbalance of the bridge.<br />

Figure 1.27 – New layout of the system, which is extremely more<br />

compact than the original one and has increased functionality<br />

A new activity started in 2010 to<br />

completely revise, design and develop the<br />

new electronics measurement system of the FTU bolmetry, which is foreseen to be completed in 2011 year<br />

(fig.1.27).<br />

The system main characteristics are:<br />

• Reduced analog hardware. Only amplification and offset removal with high precision components<br />

• 16 bit over sampled (250 KHz) <strong>di</strong>gitalization. Each output sample assuming 1 KHz depends on 250 samples<br />

giving a noise reduction of ≈16 in the complete analog/acquisition process.<br />

• References acquisitions. Further the bridge signal also the bridge reference is acquired.<br />

• Vector voltmeter algorithm. Fully <strong>di</strong>gital and numeric algorithms, the vectorial components of the signal are<br />

evaluated. This allows the complex offset removal of the bridge avoi<strong>di</strong>ng the manual hardware<br />

compensation of the cable lenght.<br />

• Digital synthesis of bridge excitation frequencies. The excitation frequencies are <strong>di</strong>gitally synthesized with 16 bit<br />

D/A at 3 MHz rate.<br />

• 4 contemporary excitation frequency in each bolometer head to remove cross talk in cables, bridges and electronics<br />

• Compactness and network integrated acquisition system any ad<strong>di</strong>tional acquisition system is necessary<br />

• Full remote control. All the bolometer functions can be remotely operated and all the parameter can be<br />

remotely visualized.


024<br />

progress report<br />

2010<br />

New <strong>di</strong>agnostics for soft x–ray imaging and tomography. Magnetic fusion plasmas (MFP) are extended sources<br />

of x–rays and these emissions could reveal a lot of information about the processes occurring inside the<br />

plasmas.<br />

The aim of this project is the development of a 2–D detector with independent energy <strong>di</strong>scrimination<br />

capability for each pixel. Plasma <strong>di</strong>agnostics based on soft x–ray (SXR) tomography and/or imaging for<br />

magnetic confinement fusion plasmas could be greatly enhanced if <strong>di</strong>fferent energy bands (which are<br />

representative of <strong>di</strong>fferent plasma zones and their impurity content) could be selected dynamically. A gas<br />

detector with 2–D pixel read–out is being proposed for such a <strong>di</strong>agnostics.<br />

Moreover, the constraints posed by toroidal devices (highly ra<strong>di</strong>ative background, extremely high<br />

ra<strong>di</strong>ofrequency powers, high magnetic fields, optical limitations and so on) are very severe and strongly limit<br />

the possibility to install x–ray detectors <strong>di</strong>rectly into, or close to the machine. Therefore, it becomes mandatory,<br />

in particular for future burning plasma experiments, to study the possibility of transporting the SXR ra<strong>di</strong>ation<br />

far from the machine. Polycapillary lenses appear promising for these purposes and suitable to be used for<br />

x–ray imaging and tomography in MFP. All these activities have been carried out in collaboration with the<br />

National Institute of Nuclear Physics (INFN) – Frascati National Laboratory (LNF) and CEA laboratory of<br />

Cadarache, under the auspices of EFDA (Work Program 2010 (WP2010)).<br />

1) Realization and characterization of a triple GEM gas detector. A triple gas electron multiplier (GEM) detector<br />

has been designed and built by the LNF–INFN laboratory of Frascati and subsequently installed in the SXR<br />

laboratory of CEA for this preliminary characterization [1.13]. It is based on a gas detector with triple GEM<br />

as amplifying structure and with a two–<strong>di</strong>mensional read–out, coupled to the integrated front–end electronics.<br />

The energy <strong>di</strong>scrimination in bands, at the level of in<strong>di</strong>vidual pixel, has been stu<strong>di</strong>ed. The front-end<br />

electronics of the GEM detector, working in photon counting mode with a selectable threshold for pulse<br />

<strong>di</strong>scrimination, is optimized for high rates.<br />

The energy resolution of the detector has been accurately stu<strong>di</strong>ed in laboratory with continuous SXR spectra<br />

produced by an electronic tube (continuous spectra with a Moxtek 40 kV Bullet) and line emissions produced<br />

by fluorescence (K, Fe, Mo), in the range 3–17 keV (fig. 1.28). For the measurements presented, the detector<br />

has been filled with a gas mixture at atmospheric pressure with<br />

10 2 counts/s<br />

6<br />

4<br />

2<br />

K<br />

Fe<br />

Mo<br />

0<br />

0 10 20<br />

Energy (keV)<br />

Figure 1.28 – SXR fluorescence of K, Fe and Mo<br />

samples measured with the Si–PIN detector<br />

Counts (Arb. units)<br />

0.6<br />

0.4<br />

K<br />

3.3 keV<br />

6.39 keV<br />

0<br />

0 100 200 300 400<br />

Energy (mV)<br />

Figure 1.29 – Reconstructed spectra for<br />

samples of K and Fe sources<br />

Fe<br />

Ar (70%) and CO 2<br />

(30%). In order to assess the intrinsic<br />

energy resolution of the detector, the <strong>di</strong>stribution of the pulse<br />

amplitude of the signals collected on a single pixel has been<br />

in<strong>di</strong>rectly derived, for <strong>di</strong>fferent K α<br />

line ra<strong>di</strong>ations (K, Fe, Mo).<br />

The integral of all the counts whose amplitude is greater than<br />

the threshold has been measured instead of the effective<br />

<strong>di</strong>stribution of the counts as function of the peak amplitude.<br />

The <strong>di</strong>stribution of the pulse amplitude has been in<strong>di</strong>rectly<br />

derived by means of scans of the threshold and by fitting it<br />

with a guess function with three free parameters: position of<br />

maximum and half width at half maximum of the Gaussian<br />

peak and decay length of the tail (fig. 1.29). The <strong>di</strong>stribution of<br />

the pulse amplitude, in the range 3–17 keV, was found nearby<br />

a Gaussian. The best agreement is found for a total detector<br />

gain of 500 and an energy resolution of about 30% and a tail<br />

at higher energy. The pulse broadening is entirely due to the<br />

poor energy resolution of the detector. Scans in detector gain<br />

have been also performed to assess the capability of selecting<br />

<strong>di</strong>fferent energy ranges. Combining together two samples, Fe<br />

and Mo, fluorescence spectra with two lines have been<br />

generated, to investigate the sensitivity of the threshold scan to<br />

a more complex spectrum.<br />

The reconstruction, by means of a threshold scan, of the<br />

incident spectrum has been demonstrated in case of simple<br />

spectra, single or double line emissions or bell shaped features.<br />

In case of more complex spectra, with <strong>di</strong>fferent features, the<br />

only scan in threshold might be not sufficient. In this case a


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

025<br />

scan in gain should also be applied, though this technique has to be<br />

fully proven in laboratory.<br />

256<br />

Now the gas detector is at the Frascati laboratories in order to continue<br />

the characterization and prepare irra<strong>di</strong>ation tests under 2.5 MeV<br />

neutron flux using the Frascati Neutron Generator (FNG) facility and<br />

in environment with ra<strong>di</strong>ofrequency interference (the FTU’s hall).<br />

Since this detector has three GEM foils for the electron amplification,<br />

it could provide the advantage to be less sensitive to neutrons and<br />

gammas as compared with the single stage one. These tests are<br />

scheduled for February 2011.<br />

2) Feasibility stu<strong>di</strong>es of polycapillary lenses. Polycapillary lenses [1.14]<br />

have been stu<strong>di</strong>ed in laboratory for preliminary characterization, with<br />

the aim of using them in SXR <strong>di</strong>agnostics such as imaging and<br />

tomography [1.15]. The first tests were performed to characterize the<br />

polycapillary lenses (convergence, <strong>di</strong>vergence, efficiency, spectral<br />

<strong>di</strong>spersion, aberrations and so on) in the SXR range 5–25 keV and for<br />

<strong>di</strong>stances much larger than the optical focal length of the lenses, both<br />

for the detector and the source. A silicon based C–MOS imager<br />

(Me<strong>di</strong>pix 2) has been used as 2D detector and the micro focus x–ray<br />

tubes as “point–like” sources.<br />

The full lens has been characterized by using an electronic tube with a<br />

Mo anode powered at 25 kV, 150 μA (continuous spectra with the K α<br />

line of Mo at 17.4 keV in ad<strong>di</strong>tion), while the half lens by using an<br />

x–ray tube with a Cu anode and a Ni filter (K α<br />

line of Cu at 8.04 keV),<br />

powered at 15 kV, 300 μA. The images have been acquired with the<br />

Me<strong>di</strong>pix 2 [1.16]. In particular, the output focus of the full lens has<br />

been found by a scan of the <strong>di</strong>stance detector–lens. The intensity of the<br />

spot is found to be fairly Gaussian and the spot broadening is linear<br />

with the <strong>di</strong>stance (60 cm) much larger than the focal <strong>di</strong>stance (4.4 cm).<br />

The total geometry <strong>di</strong>vergence results to be approximately equal to 2.6°. The same measurement has been<br />

done with the half lens: set at 25 kV and 150 μA respectively. A ra<strong>di</strong>ography of the samples has been done at<br />

first (fig. 1.30) by putting it just in front of the detector, to check structure, contrast and <strong>di</strong>mensions and so on,<br />

as reference. The image through the lens is obtained by putting the samples just before (roughly 5 mm) the<br />

optics. These samples have been perfectly reproduced (fig. 1.31). There is only a decrease in the intensity at<br />

the edges of the lens, but it could be corrected by using an appropriate factor.<br />

Imaging properties have been therefore demonstrated for full–lens, with a resolving power at least of about<br />

100 and for <strong>di</strong>stances much longer (15 times) than the focal <strong>di</strong>stance. Efficiency is found to be progressively<br />

lower at the edge, as expected, and dependent on the energy of the x–ray photons. Half–lens revealed as an<br />

excellent light collector, having an output beam with a very low <strong>di</strong>vergence (quasi parallel).<br />

New <strong>di</strong>agnostic for dusty plasmas. The research activity on dust in tokamak plasmas during the year 2010 was<br />

in part devoted to the development of a final design and construction of a specific <strong>di</strong>agnostics for the detection<br />

of micrometer size dust particles, which impinge on the vacuum chamber wall at velocities larger than a few<br />

km/s, i.e. larger than the velocity of the compressional waves of the wall material. Such particles are particular<br />

harmful for fusion reactors because, depen<strong>di</strong>ng on their size and concentration, they may significantly<br />

contribute to the wall erosion due to the impact craters produced (the erosion rate evaluated on the basis of<br />

the FTU results is indeed of the order of 10 –4 –10 –3 mm/s). Their presence in FTU was suggested by the<br />

detection of spikes in the ion saturation current collected by an electrostatic probe, interpreted in terms of<br />

impact ionization events, and by the impact craters found on the molybdenum probe tip [1.17, 1.18]. The new<br />

<strong>di</strong>agnostics, developed to confirm and extend such observations, is based on the simultaneous detection of the<br />

spikes in the ion saturation current collected by an electrostatic, tungsten probe and the light flashes emitted<br />

by the tungsten vapour cloud formed by the impact. This coincidence allows indeed to <strong>di</strong>scriminate between<br />

events due to plasma fluctuations, which are not accompanied by line emission of tungsten, and events due to<br />

hypervelocity impacts. A detailed study of feasibility of the new electro–optical (EO) probe has been<br />

performed [1.19]. The main concern was represented by the background plasma emission, mainly due to the<br />

X<br />

1<br />

256 Y (Row number) 1<br />

0<br />

19.18 38.35 57.53 76.7<br />

Figure 1.30 – Ra<strong>di</strong>ography of a<br />

plastic foil with holes<br />

1<br />

X<br />

256<br />

1 Y (Row number)<br />

256<br />

0 36.83 73.66 110.5 147.3<br />

Figure 1.31 – Image with a full lens<br />

of a plastic foil with holes


026<br />

progress report<br />

2010<br />

S(μ W/sr nm)<br />

1.5<br />

0.5<br />

-0.5<br />

0<br />

200 400<br />

Time (ns)<br />

Figure 1.32 – Emissions observed by<br />

four spectral channels (blue 1020–1050<br />

nm, green 950–1020 nm, orange<br />

850–950 nm, cyan 670–850 nm)<br />

Bremsstrahlung ra<strong>di</strong>ation. Accurate evaluations suggest that the<br />

tungsten line emission at 401 nm (selected by an interference filter<br />

with full width at half maximum (FWHM) ≤1 nm) by the impact<br />

vapour cloud is expected to be larger than the background ra<strong>di</strong>ation<br />

by two orders of magnitude during a time interval of the order of a<br />

few hundred ns after the impact. The construction of the mechanical<br />

parts of the probe was completed in 2010. The installation of the<br />

probe in the FTU port 5, as well as the final assembly of the optical<br />

and electrical detection systems (inclu<strong>di</strong>ng data acquisition) should<br />

be completed by 2011. It is worth noticing that the project was<br />

developed with a strong support, both financial and scientific,<br />

provided by the IFP of the CNR, Milan, also in the frame of a<br />

collaboration with the University of Naples “Federico II”, the University of Molise and the Royal Institute of<br />

Technology (KTH) of Stockholm. The EO probe development was also supported by Ministero<br />

dell’Università e della Ricerca (MiUR) under grant PRIN–2007L4YEW4 and by EFDA baseline and priority<br />

supports.<br />

Another important issue considered in the framework of dust particle stu<strong>di</strong>es in tokamak environments was<br />

the detection of dust mobilized after <strong>di</strong>sruptions. Such dust particles were observed by the new high resolution<br />

Thomson scattering system on Joint European Torus (JET) [1.20]. The system consists of filter spectrometers<br />

that analyze the Thomson scattering spectrum from 670 to 1050 nm in four spectral channels. The laser source<br />

was a 5 J Q–switched Nd:YAG laser. Without a spectral channel at the laser wavelength, the dust elastic<br />

scattering cannot be observed and only dust particles that emit broadband light could be detected. The time<br />

behaviour of their emission is clearly <strong>di</strong>fferent from that expected for a Thomson scattering pulse. As shown<br />

in figure 1.32, the emission peak is actually delayed by about 10 ns as compared to the laser pulse (15 ns<br />

duration). Moreover, the typical emissions observed by the spectral channels have almost the same amplitude,<br />

consistent with a black body emission of dust particles with a <strong>di</strong>ameter of 10 μm at a temperature of 4000 K.<br />

The fast decrease of the signal after the peak (10 ns time scale) suggests the occurrence of ablation<br />

phenomena, since the ra<strong>di</strong>ative cooling is expected to be much slower. These stu<strong>di</strong>es concerning the detection<br />

of dust during <strong>di</strong>sruptions at JET are preliminary, further investigations are planned for the next JET<br />

campaigns C28 and C29.<br />

It is worth noticing that the characterisation of size, composition and origins of dust in fusion devices is the<br />

subject of a specific International Atomic Energy Agency (IAEA) Coor<strong>di</strong>nate Research Project (CRP), and the<br />

FTU group is involved in this project by provi<strong>di</strong>ng the chief scientific investigator. The report of the second<br />

research coor<strong>di</strong>nation meeting of this project has been published in November 2010 [1.21].<br />

These researches can benefit from collaboration with scientists involved in <strong>di</strong>fferent fields, such as the study of<br />

dust in laboratory or space plasmas [1.22].<br />

Ion cyclotron antennas. The collaboration between IPP – Garching and <strong>ENEA</strong>–Frascati started more than one<br />

year ago, but has been effective since spring 2010. It is essentially focused on the solution of one major open<br />

issue related to ion–cyclotron (IC) antennas, namely the capability to reach both good plasma coupling and<br />

low sheath potentials in front of the launchers. In particular, the sheath potentials are responsible for high<br />

impurity production and their reduction is still a huge challenge for the design of high power ion cyclotron<br />

resonance frequency (ICRF) antennas, with specific relevance to ITER and FAST experiments.<br />

In this context Axially Symmetric Divertor EXperiment Upgrade (Asdex–U) stands out to be one of the best<br />

can<strong>di</strong>dates to test new IC antenna solutions due to its H–modes and to the fully tungsten wall. Furthermore,<br />

the Asdex–U team has a remarkable experience in terms of antenna design and sputtering yield analysis, as<br />

proved by its long list of references and international collaborations ([1.23, 1.24] to cite only a few) on these<br />

topics.<br />

The present work is focused on two main activities, i.e. the modelling and simulation of the actual AUG IC<br />

antennas, and the design of a new launcher to be installed on the machine by mid 2012. Two main pre<strong>di</strong>ction<br />

tools are being used for this purpose, HFSS and TOPICA [1.25], whose results have been compared as far as<br />

rectified potentials are concerned (the integral of the parallel electric field component along magnetic field<br />

lines in front of the antenna).<br />

HFSS is a 3D full–wave frequency domain electromagnetic field solver based on the finite element method,


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

027<br />

Fields are predominantly real<br />

Re E II<br />

(kV/m)<br />

HFSS<br />

-0.5<br />

Rectified potentials<br />

voltage (kV)<br />

0.6<br />

0.4<br />

0.2<br />

0.0<br />

Z<br />

0.0<br />

(m)<br />

(m)<br />

0.6<br />

0.3<br />

0.0<br />

-0.3<br />

HFSS<br />

TOPICA<br />

-0.5 0 0.5<br />

Z (m)<br />

Z<br />

TOPICA<br />

-0.6<br />

0.5 -0.5 0.0 0.5<br />

(m)<br />

Figure 1.33 – Comparison<br />

between E–field <strong>di</strong>stribution<br />

and rectified potentials<br />

calculated with TOPICA and<br />

HFSS for a 2–strap flat antenna<br />

loaded with a lossy <strong>di</strong>electric.<br />

Values are normalized to 500<br />

kW per strap<br />

Figure 1.34 – Reference and broad limiter<br />

antennas together with their TOPICA<br />

models (left Faraday screen has been<br />

hidden to make the interior visible)<br />

Figure 1.35 – Preliminary CAD<br />

drawing of the 3–strap<br />

antenna<br />

while TOPICA is a 3D full–wave boundary–value<br />

problem using a hybrid spatial–spectral domain<br />

formulation. In ad<strong>di</strong>tion to the <strong>di</strong>fferent formulation<br />

and other minor <strong>di</strong>fferences, the former can only take<br />

into account <strong>di</strong>electric loa<strong>di</strong>ngs, while the latter also<br />

accounts for magnetized, inhomogeneous and hot<br />

plasmas solved in slab approximation with the finite<br />

element method.<br />

Up to now modelling and simulation of the present Asdex–U IC antennas has been following a stepwise<br />

approach. Firstly the consistency of results between HFSS and TOPICA has been successfully verified in case<br />

of <strong>di</strong>electric loaded antennas for flat approximated geometries. Good agreement has been found between the<br />

<strong>di</strong>fferent tools both in terms of coupled power and electric field <strong>di</strong>stribution (fig. 1.33) in front of the launcher.<br />

Then, the real 3D geometry of the IC antennas has been imported in TOPICA for realistic simulations. The<br />

“reference” antenna – a 2–strap antenna with narrow side limiters – has been modelled both as it is now and<br />

as it was before 2010, since the top limiter underwent some small changes between the latter and the current<br />

experimental campaigns. Furthermore, the broad limiter antenna – an antenna with broader limiters, thinner<br />

straps and two ad<strong>di</strong>tional poloidal side plates – has been modelled too (fig. 1.34). The latter is expected to<br />

achieve a moderate reduction of the rectified potentials as compared to the aforementioned reference antenna.<br />

Two further steps are presently being envisaged. First, TOPICA simulations of the flat and curved antenna<br />

geometries have to be compared for several plasma profiles. Second, an assessment of TOPICA pre<strong>di</strong>ctions<br />

as far as Asdex–U experimental data are concerned has to be performed as soon as such data become<br />

available.<br />

As far as the design of a new IC antenna is concerned, <strong>di</strong>fferent solutions have been proposed and simulated<br />

with HFSS and/or TOPICA. In quite recent times, even though at a preliminary stage, much attention has<br />

been payed to a 3–strap antenna solution (fig. 1.35), where image currents, circulating on the limiters and<br />

usually causing high rectified potentials, are strongly reduced by a compensation mechanism between central<br />

and outer straps. Unfortunately, to achieve this result, the requirements in terms of phase tuning and power<br />

balance between straps are very deman<strong>di</strong>ng and they have to cope with severe mechanical constraints.


028<br />

progress report<br />

2010<br />

Transmission and relative reference<br />

spectrum (red)<br />

1.2<br />

0.8<br />

0.4<br />

0<br />

290 GHz<br />

nominal low-pass<br />

Wire grid polariser, E ⊥ wires<br />

Fabry-Perot<br />

Mylar Mesh<br />

Reference spectrum<br />

0.4 1.2<br />

Frequency/THz<br />

WG polariser:<br />

E// wires<br />

Figure 1.36 –Spectral response of <strong>di</strong>fferent<br />

materials and components measured with the<br />

TDS–THz spectrometer. WG is short for<br />

Wire–Grid polarizers, the brown line<br />

corresponds to a 250 GHz low–pass filter. Note<br />

that the SNR in the measurements is unchanged<br />

along the spectral range under investigation,<br />

although the relative intensity of the reference<br />

spectrum (red) ranges across a factor 10<br />

2<br />

Novel approach to the submillimeter and THz plasma<br />

<strong>di</strong>agnostics. The Terahertz (THz) band of the<br />

electromagnetic spectrum is defined as the range of<br />

frequencies between microwaves and mid–infrared light,<br />

covering the region where electronic and optical technologies<br />

overlap. Recently, femtosecond laser pulses have been used to<br />

generate extremely broadband (100 GHz to 30 THz)<br />

single–cycle THz pulses. These pulses can be detected<br />

coherently with very high sensitivity, and may be used for<br />

time–domain spectroscopy (TDS) experiments on a variety of<br />

systems, with a great potential for plasma <strong>di</strong>agnostics in this<br />

area of the electromagnetic spectrum, i.e. electron cyclotron<br />

emission (ECE), reflectometry, interferometry. A<br />

Collaboration between <strong>ENEA</strong> Frascati and Oxford Terahertz<br />

Photonics Group on this subject has started in 2010, and a<br />

memorandum of understan<strong>di</strong>ng has been signed by the Head<br />

of UTFUS–MAG Frascati and the leader of Oxford<br />

Terahertz Fotonics, an excellence research group within the<br />

sub–faculty of Physics at the University of Oxford.<br />

The introduction of the reliable THz–TDS cutting–edge<br />

technology in the tokamak environment will allow high<br />

sensitivity, due to the background rejection potential of this<br />

technique. With this system background ra<strong>di</strong>ation can be<br />

rejected extremely well, to easily detect sub–micro watt average power. A great advantage will be the use of<br />

sources and detectors intrinsically broadband, like a Fourier Transform Spectrometer, but without the<br />

beamsplitter restrictions, and, not negligible, they are solid–state devices, operating at room temperature.<br />

The <strong>di</strong>agnostic potential of the existing instrumentation has been assessed at the Oxford Clarendon<br />

laboratory. Preliminary laboratory tests have been carried out, for phase measurements, windows and<br />

materials characterization, and signal to noise ratio (SNR) (fig. 1.36). A new type of THz spectrometer is being<br />

jointly developed: this system operates entirely with optical fibers, which would allow the usual <strong>di</strong>fficulties of<br />

installing receiving and transmitting antennae in a tokamak to be overcome.<br />

The conceptual design of the new plasma <strong>di</strong>agnostic system, with quantities to be measured, parameters<br />

range and measurement precision is in progress.<br />

On the same front, a complementary line of work is in progress in collaboration with General Atomics, San<br />

Diego. This action takes place under the Large Tokamak Cooperation (LTC) scheme. The use of a high<br />

resolution Fabry Perot interferometer for plasma real–time control purpose is being stu<strong>di</strong>ed, and laboratory<br />

tests took place both in Frascati and at DIII–D. Two instruments of this kind are being realised simultaneously<br />

in the two laboratories. On this front the work will merge with the THz device line of research, with the<br />

combination of quasi–optical and electronics devices, which has never been implemented in Fusion, and also<br />

offers a great range of applications in other areas.<br />

We aim to improving the <strong>di</strong>agnostic capabilities beyond the routine plasma density and temperature<br />

measurements, thus moving towards the measurement of fluctuations, charge density and conductivity, with<br />

unprecedented temporal, spatial and spectral resolution.<br />

Other <strong>di</strong>agnostics development for FTU<br />

Study of fast events. In order to study events that occur on time scales shorter than milliseconds (such as the<br />

quenching phase following plasma <strong>di</strong>sruptions, the dust behaviour, correlations between density oscillations<br />

and Marfes, etc), some upgrade of the FTU <strong>di</strong>agnostic system has been introduced:<br />

• A fast camera Photron SA4 has been installed on Port 6. The new camera can operate up to 3600 frames/s<br />

at full resolution or up to 500000 frames/sec at the smallest resolution). Image transport through the Port<br />

plasma is obtained with a high quality fibre bundle.<br />

• New spectral line monitors with fast ADC (CAEN DT5724 4 channel 14 MS/s Digitizer) allow observation<br />

of H α<br />

(6563Å, MoI (3864 Å, 5503 Å), LiI 6104 Å, BII (7031 Å), CIII (4647 Å) to be performed with time<br />

resolutions up to 10 μs.


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

029<br />

• 2 existing visible polychromators have been set on higher acquisition rates<br />

• The multichord interferometer has been upgraded to 1.5 MHz acquisition frequency.<br />

New acquisition system for magnetic probes. The new system based on analog–<strong>di</strong>gital converter (ADC) on the<br />

PXI crates is presently being tested on 16 poloidal sensors and 10 saddle coils. The final system will acquire<br />

12 bit samples at a maximum rate of 500 Hz on 192 channels.<br />

Tests of compact MHD sensors. The new sensors, low temperature co–fired ceramic technology (LTCC) coils<br />

developed by Centre de Recherches en Physique des Plasmas (CRPP) – Lausanne, are constituted by 3×3 cm 2<br />

ceramic plates, which embed the conducting coils, featuring a wide effective area and an extreme compactness.<br />

A linear response up to 500 kHz and a sensitivity 7 times higher than the conventional Mirnov coils in use on<br />

the FTU poloidal limiter have been measured. Two of these sensors have been mounted aside a conventional<br />

MHD coil on the extractable poloidal limiter, with the same orientation, in order to be tested during FTU<br />

operation. The resistance to ra<strong>di</strong>ation and thermal stresses will also be investigated.<br />

Fast equilibrium reconstruction code. A real time version of the equilibrium code ODIN is currently under<br />

implementation; among its advantages, a better behaviour of the control feedback, with ad<strong>di</strong>tional<br />

information on internal flux surfaces and the possibility to track a flux surface for ECRH heating can be<br />

counted. As a result of the optimization, the code is now able to obtain a reconstruction in 10 ms on average.<br />

Parallelization of the code is under examination; this is expected to reduce the elaboration time to about 2 ms<br />

per each time frame. The code will be tested on FTU <strong>di</strong>scharges on the next campaign.<br />

The time–of–flight refractometer with double frequencies. A pulsed double frequency refractometer, realized by<br />

the Russian company SPHERAtec, has been installed in FTU to measure the line average density from the<br />

time of flight of the wave packet through the plasma. The two frequencies employed are 51.5 GHz and 60.5<br />

GHz. The pulses alternatively produced by the two generators, each with a length of 8 ns and a repetition<br />

rate of 250 kHz, are channelled in a single waveguide and sent to the plasma. Part of the signal is spilled by<br />

a <strong>di</strong>rectional coupler for the reference signal. The oscillators are synchronized by a master clock. Once the<br />

pulses are launched to the plasma, they are reflected back by the vacuum vessel and detected by the receiver<br />

unit. The output signals from the reference and the receiver units are send to a pulse former PF and then to<br />

the time–to–voltage converter, which provides a voltage proportional to the time delay between the two pulses.<br />

Plasma–wall interaction<br />

Activities concerning the plasma-wall interaction have been continued during the year 2010 on several issues,<br />

in the frame of EFDA task agreements (TAs) and collaboration between FTU and ASDEX–U. Concerning<br />

EFDA TAs, in 2010 <strong>ENEA</strong> was in charge of the coor<strong>di</strong>nation of the task concerning the “Development of the<br />

PWI basis in support of integrated high–Z scenarios for ITER. Demonstration of liquid plasma–facing<br />

components” (activity TA–WP10–PWI–05–00/<strong>ENEA</strong>/PS). Task WP09–PWI–05–01/<strong>ENEA</strong>/BS and PS:<br />

“Injection of noble gases (Ne and possibly Ar) in the FTU <strong>di</strong>scharges for testing its effect on the production of<br />

high–Z impurities (Mo from the toroidal limiter)” was concluded in 2010 by further analysis of the data<br />

collected in 2009. No new experiment was possible due to the FTU inactivity in 2010. In the examined ohmic<br />

<strong>di</strong>scharges with B T<br />

=6 T, I p<br />

=500 – 800 kA, n e<br />

=0.7–1.6×10 20 m –3 , characterized by negligible pre–Ne injection<br />

Mo influx, no Mo influx following Ne injection was found: in the few cases where more consistent Mo influx<br />

was present before the Ne injection, no increase, and often a decrease, in its amount was observed.<br />

Collaboration with ASDEX–U. In the first half of 2010, a proposal for testing the capability of CREATE<br />

software tools to mitigate the heat load on the <strong>di</strong>vertor tiles by decreasing the inclination angle of the<br />

separatrix at the outer strike point was submitted to the IPP<br />

management. The upper part of the plasma was frozen<br />

and the separatrix was moved just in the neighbourhood of<br />

the inner strike point (ISP) and outer strike point (OSP). In<br />

figure 1.37 the reference and the mo<strong>di</strong>fied equilibrium for<br />

an ASDEX–U shot are reported. De<strong>di</strong>cated plasma shots<br />

will be allocated in the 2011 ASDEX–U experimental<br />

program.<br />

Z(m)<br />

-0.7<br />

-0.9<br />

-1.1<br />

Reference<br />

+7 cm (ISP),<br />

-6 cm (OSP)<br />

Figure 1.37 – Reference (blue) and mo<strong>di</strong>fied (green)<br />

equilibrium for an ASDEX–U shot<br />

-1.3<br />

1<br />

1.2 1.4 1.6 1.8 2<br />

R(m)


030<br />

progress report<br />

2010<br />

1.3 Plasma Theory<br />

Significant efforts of theoretical research activities have been devoted to analyzing nonlinear behaviors in<br />

burning plasmas of fusion interest, their complex dynamics and the issues that arise when modeling these<br />

phenomena with increasingly more realistic physics and equilibrium descriptions. Many of these theoretical<br />

activities significantly contributed to advancing the FAST conceptual design; the activities specifically carried<br />

out within the framework of this project are summarized in the specific FAST section.<br />

Several activities of the plasma theory group have been pursued in the framework of international<br />

collaborations with the University of California at Irvine (UCI) and the Institute for Fusion Theory and<br />

Simulation (IFTS), Zhejiang University (ZU), Hangzhou (China), namely: the nonlinear <strong>di</strong>spersive properties<br />

of low–frequency shear Alfvén waves in the presence of magnetic islands which have been successfully used<br />

for interpreting experimental observations in FTU, and the analyses of geodesic acoustic modes (GAM)<br />

excitation by supra–thermal particles and of kinetic structures of low–frequency shear Alfvén as well as the<br />

acoustic wave spectra with their interactions with fast ions. Other examples of fruitful international<br />

collaborations and local research efforts that are impacting international research projects are given by the<br />

continuing benchmarking activities of the hybrid magnetohydrodynamic gyrokinetic code (HMGC) within the<br />

framework of the ITPA – Topical Group (TG) on energetic particle physics, the investigation of theoretical<br />

issues to be applied for optimization of ITER magnetic <strong>di</strong>agnostics and the work carried out as contribution<br />

to the ITM–TF.<br />

The development of advanced numerical simulations tools, which exploit the most modern, massively parallel<br />

architectures for high performance computing, continued with the implementation and testing of the new<br />

hybrid magnetohydrodynamic gyrokinetic code (HYMAGYC). At the same time, further implementation and<br />

applications of the extended HMGC (XHMGC) hybrid code have been pursued in collaboration with UCI,<br />

IFTS and the US Scientific Discovery trough Advanced Computing (SciDAC) Gyrokinetic Simulation of<br />

Energetic Particle (GSEP) turbulence and transport Project. XHMGC is now a very flexible and versatile tool<br />

for investigations of burning plasma physics issues, which are made possible thanks to the increasingly more<br />

realistic description of the supra–thermal particle dynamics (in collaboration with the Japan Atomic Energy<br />

Agency (JAEA)) and are mostly focused on fundamental physics stu<strong>di</strong>es and applications to FAST (see the<br />

FAST section). As a further example of fundamental physics stu<strong>di</strong>es being pursued in burning plasmas of<br />

fusion interest, there is the characterization of complex dynamics and fishbone instability for self-organized<br />

critical systems.<br />

Fundamental properties of LH wave interactions with burning plasmas have been addressed, both with<br />

explorations based on analytic techniques as well as with Hamiltonian perturbation theory methods and with<br />

a full wave equation approach, for investigating wave propagation properties in regions with sharp density<br />

gra<strong>di</strong>ents, such as those characterizing the H–mode plasma edge. Meanwhile, a new ion–heating scenario,<br />

based on cyclotron damping of ion Bernstein waves (IBW) by tritium minority has also been addressed. Finally,<br />

with emphasis on broader applications and implications of plasma physics, its role in the morphology of<br />

accretion <strong>di</strong>scs and on the mechanism for the generation of stellar winds or matter-jet seeds has been<br />

addressed, in collaboration with the University of Rome “La Sapienza” and International Center for<br />

Relativistic Astrophysics Network (ICRANet).<br />

Alfvén modes in the presence of a magnetic island<br />

The dynamics of Alfvén modes in plasma equilibria with a quasi–static magnetic island has been investigated<br />

in the framework of an ideal MHD model [1.26] (in collaboration with Physics Dept. of the University of Pisa,<br />

and Department of Physics and Astronomy of the UCI). A generalized safety factor has been defined inside<br />

the magnetic island flux tube, giving information on the rational flux surfaces where <strong>di</strong>fferent modes couple<br />

and create gaps in the shear Alfvén wave (SAW) continuous spectrum. It has been found that a SAW<br />

continuous spectrum exists, which is similar to that calculated in tokamak equilibria. A typical size magnetic<br />

island is shown to induce wide gaps in the continuous spectrum, due to the strong eccentricity of the closed<br />

flux surfaces inside the island. The central frequency of the gap, near the O–point, is [1.27, 1.28]<br />

f MiAEgap =f BAECAP<br />

2 2 2<br />

1+Mn islfA<br />

/fBAECAP<br />

3)


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

031<br />

where M=(q 2 0 s2 /2)(W isl<br />

/r o<br />

) is the parameter accounting for the<br />

magnetic island amplitude, f BAE–CAP<br />

is the BAE continuum<br />

accumulation point and f A<br />

is the Alfvén frequency (the MiAE<br />

subscript stan<strong>di</strong>ng for magnetic island induced Alfvén eigenmode).<br />

Here q 0<br />

,s,r o<br />

are, respectively, the safety factor, the magnetic shear<br />

and the ra<strong>di</strong>al position at the mode rational surface, and W isl<br />

is the<br />

magnetic island half width. This phenomenon is analogous to the<br />

formation of ellipticity–induced Alfvén eigenmode (EAE) gaps in<br />

tokamaks [1.29] but, here, it is localized inside the magnetic island<br />

separatrix. When considering modes with the same helicity as the<br />

magnetic island, the frequency of the nonlinearly mo<strong>di</strong>fied BAE<br />

continuum accumulation point (BAE–CAP) has been calculated.<br />

The existence of MiAE, namely the global Alfvén eigenmode (AE)<br />

localized inside the magnetic island, has been investigated. The<br />

case of small eccentricity of the flux surfaces has been considered,<br />

for this is the case that can be investigated with analytical<br />

techniques. As a result, the <strong>di</strong>spersion relation of eccentricity<br />

induced MiAE (or MiEAE) has been calculated. Moreover, the<br />

contribution of finite Larmor ra<strong>di</strong>us terms was found to be crucial<br />

to create the potential well for other AEs. These modes, with<br />

characteristic length scale of the order of the ion Larmor ra<strong>di</strong>us,<br />

have been identified as kinetic MiAE (or MiKAE). Their frequency<br />

is pre<strong>di</strong>cted to be above the MiAE gap and they are localized in a<br />

region close to the rational surface (fig. 1.38).<br />

It has also been shown that the SAW continuous spectrum in<br />

finite–beta tokamak plasmas and in the presence of a magnetic<br />

island is still characterized by the beta–induced gap at low<br />

frequencies. This window in the Alfvén continuum, namely<br />

0


032<br />

progress report<br />

2010<br />

1.4<br />

1<br />

0.6<br />

0.2<br />

-0.2<br />

0 0.2<br />

ω G (r)/ω tr,b<br />

Im (δE)<br />

Re(δE)<br />

0.4 0.6 0.8 1<br />

r<br />

Figure 1.40 – The global mode structure<br />

of EGAM in the case of exponentially<br />

small EGAM tunneling coupling to KGAM.<br />

Here, the GAM frequency at the beam<br />

intensity peak is slightly larger than the<br />

beam transit frequency; ω G (r b ) ≅ 1.1ω tr,b<br />

That EPs can drive GAMs has been observed in recent experiments<br />

[1.39,1.40] and theoretical stability properties of this<br />

energetic–particle–induced GAM (EGAM) were presented in<br />

[1.41]. While the continuous spectrum is one of the key features of<br />

GAMs, previous theoretical treatments [1.37,1.39,1.41–1.45] often<br />

ignored it by either focusing on the derivation of local <strong>di</strong>spersion<br />

relations or introducing the ad hoc assumption that modes are<br />

localized near an extremum of the continuous spectrum [1.46,1.47]<br />

and, thereby, neglecting its associated ra<strong>di</strong>al structures.<br />

Reference [1.48] first investigated the excitation of EGAM<br />

accounting for the GAM continuous spectrum, thus demonstrating<br />

the analogy between EGAM and EPM. The correspon<strong>di</strong>ng<br />

<strong>di</strong>spersion relation exhibits the finite threshold con<strong>di</strong>tion in EP drive<br />

due to the continuum damping of the global EGAM when it is<br />

strongly coupled to the GAM continuum. In this work, the<br />

excitation of EGAM has been considered when its coupling to the<br />

GAM continuum is formally exponentially small, analogous to the correspon<strong>di</strong>ng EPMs excited by localized<br />

EP sources [1.49]. The mode, meanwhile, is excited via the transit frequency resonance of EPs in the small<br />

magnetic drift orbit limit. This case has been analyzed as being complementary to the global EGAM stability<br />

problem analyzed earlier, assuming finite size magnetic drift orbits and strong coupling to the GAM<br />

continuous spectrum [1.49]. Since the frequency and mode structure of EP modes are determined by the EPs,<br />

EPs have been treated on the same footing as the bulk plasma, i.e. nonperturbatively. Both local and nonlocal<br />

<strong>di</strong>spersion relations of EGAM are derived by assuming single pitch angle slowing–down energetic ion<br />

equilibrium <strong>di</strong>stribution function. For a sharply localized EP source, it is shown that the mode is self–trapped<br />

where the EP drive is strongest [1.50], with an exponentially small damping due to the tunneling couplied to<br />

the GAM continuous spectrum, where the EGAM is mode converted to a short wavelength kinetic GAM<br />

(KGAM) [1.47], which propagates outward, as shown in figure 1.40 [1.50] and consistent with<br />

observations [1.51].<br />

Kinetic structures of shear Alfvén and acoustic wave spectra in burning plasmas<br />

The low frequency fluctuation spectra of shear Alfvén and acoustic waves are important to burning plasmas<br />

of fusion interest, since they can be excited by both thermal as well as supra–thermal particles in various<br />

parameter regimes. There is an increasing consensus that accurate treatments of key physics processes of these<br />

spectra do require a kinetic approach [1.46,1.52–1.60]; although whether a fully kinetic approach is really<br />

necessary is still being debated [1.61].<br />

In this work [1.62], recently derived analytic theories are briefly summarized, which demonstrate the crucial<br />

importance of employing kinetic analyses for fundamental processes in collisionless plasmas of fusion interest<br />

in the low frequency regime, i.e., where geometry effects, magnetically trapped particles [1.59,1.60], wave<br />

particle interactions and finite (kinetic) plasma compressibility play major roles. Analytic expressions show that<br />

the acoustic branch is generally more strongly damped than the shear Alfvén branch, which is the one of<br />

practical interest for interpreting experimental observations. Meanwhile, analytic calculations can be used to<br />

benchmark results of numerical codes in the relevant limits [1.60,1.63], thus helping their verification<br />

processes. Possible further extensions of present analytic theories, which are already underway, have also been<br />

considered.<br />

ITPA benchmarking activity using HMGC<br />

The benchmark activity, proposed by the ITPA topical group on energetic particle physics, between the hybrid<br />

MHD–gyrokinetic particle in cell codes HMGC [1.64] and MEGA [1.65], and the gyrofluid code TAEFL<br />

[1.66] has been continued. In particular, the shear Alfvén mode stability of a model equilibrium characterized<br />

by aspect ratio R 0<br />

/a=0.1, safety factor q(s) =1.1 + 0.8116 s 2 , with s=(1–ψ/ψ 0<br />

) 1/2 , β bulk<br />

=0 and normalized<br />

bulk density profile n i<br />

(s)/n i0<br />

=[q 0<br />

/q(s)] 2 , has been analyzed in the presence of an energetic particle <strong>di</strong>stribution<br />

function given by F(P ϕ<br />

,E)= (m H<br />

/2πT H<br />

) 3/2 n H0<br />

exp(k m H<br />

cP ϕ<br />

/e H<br />

|ψ 0<br />

|) exp(–E/T H<br />

), with T H<br />

=T H0<br />

and<br />

P ϕ<br />

=–(e H<br />

/m H<br />

c) |ψ 0<br />

| s 2 +v <br />

R. A energetic particle profile (k=2.5) steeper than that of the previous benchmark


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

033<br />

test case (k=2.0) has been considered in order to emphasize the core<br />

plasma dynamics.<br />

Figure 1.41 compares codes’ results showing the growth rates of<br />

<strong>di</strong>fferent modes (internal, half–ra<strong>di</strong>us EPM and outer gap mode)<br />

versus n H0<br />

/n i0<br />

.<br />

γ/ω A<br />

1<br />

0.06<br />

HMGC-internal<br />

HMGC-gap<br />

HMGC-epm<br />

MEGA-epm<br />

MEGA-internal<br />

TAEFL-internal<br />

TAE eigenfunctions for ITER magnetic <strong>di</strong>agnostics<br />

In the frame of the F4E task “F4E–2009–GRT–047 System-level<br />

optimization of the ITER magnetic <strong>di</strong>agnostics”, the full MHD<br />

code MARS [1.67] has been used to generate the magnetic field<br />

perturbation at the plasma surface as generated by a tipical toroidal<br />

Alfvén eigenmode (TAE). An ITER equilibrium (reference scenario<br />

2) has been generated by the code FIXFREE, which can produce an<br />

-0.02<br />

0.0018 0.0022<br />

EQDSK file as output, which, in turn, has been given as input to the high resolution equilibrium code<br />

CHEASE, in order to generate a suitable equilibrium input for the stability code MARS. MARS has been used<br />

first to found the Alfvén continuous spectra for a variety of toroidal mode numbers, in order to identify the<br />

frequency range were the toroidal gap appears. Secondly, the MARS code has been used to obtain the global<br />

eigenmodes (TAEs), which exist with frequencies that lie in the toroidal gap; moderate toroidal mode numbers<br />

(n∼10) have been used, and the 2D spatial structure of the magnetic field perturbations at the plasma/vacuum<br />

interface for a specific toroidal location have been produced. Such perturbations will be used as a benchmark<br />

to test the goodness of the magnetic measurements envisaged for ITER in reconstructing mode structures.<br />

0.02<br />

0<br />

0.0026 0.003<br />

n H0 /n i0<br />

Figure 1.41 – Growth rates vs n H0 /n i0 for<br />

shear Alfvén modes found by HMGC,<br />

MEGA and TAEFL codes<br />

ITM–TF activities<br />

The activities of the Frascati theory and modeling group in the frame of the ITM–TF in year 2010 were<br />

concentrated on the Integrated Modelling Project 5 (IMP5) “Heating, current drive and fast particles”. Beside<br />

continuing the development and testing of the new Hybrid MHD–Gyrokinetic Code HYMAGYC (see next<br />

section), the main activity of this year was concentrated on porting the codes on the Gateway and interfacing<br />

them with the ITM environment (Consistent Physical Objects (CPOs), Kepler actors, Kepler workflows).<br />

The codes involved in this activity are, by now, HYMAGYC, HMGC and RAYLH. During the year 2010 a<br />

strong activity has been carried out for critically revising the completeness and the definitions of several<br />

quantities stored in the equilibrium and the coreprof CPOs (the first usually written by equilibrium solvers,<br />

the second usually written by a transport solver, as, e.g., the European Transport Solver (ETS) developed<br />

within the ITM–TF, or, alternatively, both obtained by experimental data): this effort has been mainly pursued<br />

by using the MHD code from which the MHD solver used in HYMAGYC comes from (the MARS code<br />

[1.67]), with the collaborative effort of other ITM projects (mainly IMP12 and IMP3). The result of this year’s<br />

activity has been very fruitful, and, as a by–product, the full MHD, resistive, general geometry code MARS<br />

has been fully ported on the Gateway, i.e., fully interfaced with the CPOs (release 4.08b); furthermore, a<br />

Kepler actor and a Kepler test workflow have been generated. This work will be propaedeutical to the porting<br />

of the full HYMAGYC, and has been crucial for the progress of the activities of the full IMP5 group.<br />

Regar<strong>di</strong>ng the code HMGC and its extended version (see next), the routines that produce the simplified<br />

equilibrium (circular cross–section geometry, shifted magnetic surfaces, low bulk plasma pressure<br />

approximation) required by the code are presently under mo<strong>di</strong>fication, and will be completed early next year.<br />

Regar<strong>di</strong>ng the code RAYLH (a ray–tracing code for lower hybrid propagation), the activity of porting the code<br />

on the Gateway and substituting the original equilibrium and plasma description (obtained by a EQDSK file)<br />

required to solve the propagation problem with the ITM CPOs has began, and will be finished early next year,<br />

together with the interfacing of the code with the complete ITM environment, with the ultimate goal, e.g., of<br />

producing a Kepler actor to be used by the ETS.<br />

The new hybrid MHD–gyrokinetic code: HYMAGYC<br />

The HYMAGYC [1.68] was built by interfacing an equilibrium module (a mo<strong>di</strong>fied version of the CHEASE<br />

code [1.69]), a MHD module (an initial–value version of the original eigenvalue MHD stability code MARS


034<br />

progress report<br />

2010<br />

δnm-1,n<br />

4×10-11<br />

2×10 -11<br />

0<br />

-2×10 -11<br />

a)<br />

3×10 -10<br />

0<br />

-1×10 -10<br />

δn m,n1×10-10<br />

b)<br />

δn m+1,n<br />

6×10-11,<br />

2×10 -11<br />

-2×10 -11 0<br />

c)<br />

-4×10 -11<br />

0<br />

40 80 120<br />

Time<br />

-3×10-10<br />

0 40 80 120<br />

Time<br />

-6×10 -11<br />

0 40 80 120<br />

Time<br />

Figure 1.42 – Fourier components of energetic particle perturbed density for a given electromagnetic field with m=4, n=4. Blue<br />

and black curves are, respectively, numerical and analytical results for the real part of density Fourier component; red and<br />

green curves are numerical and analytical results for the imaginary part. a) δn m-1,n b) δn m,n c) δn m+1,n<br />

[1.67], adapted for the computation of the perturbed scalar and vector potentials, besides the perturbed<br />

magnetic and velocity fields) and a gyrokinetic particle–in–cell module (yiel<strong>di</strong>ng the energetic ion pressure<br />

tensor returned to the MHD solver). The gyrokinetic module had been previously tested as to the single<br />

particle orbits in equilibrium fields.<br />

In order to test the response of energetic particles to a given electromagnetic field, an analytical model has<br />

been developed for large aspect ratio equilibrium with circular magnetic flux surfaces and flat q profile, and<br />

for circulating energetic particles with ρ H<br />

/a


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

035<br />

|φ(r)| (Arb. units) |φ(r)| (Arb. units)<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

0<br />

0<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

a)<br />

1<br />

(1,3)<br />

b)<br />

1<br />

(2,3)<br />

c)<br />

(5,3)<br />

(6,3)<br />

(7,3)<br />

0.8<br />

0.6<br />

(8,3)<br />

(9,3) 0.6<br />

0.2<br />

(10,3)<br />

(11,3)<br />

0<br />

(12,3) 0.4<br />

-0.2<br />

ω/ω A0 ω/ω A0<br />

0.2<br />

0<br />

-1<br />

0.4 0.8<br />

0 0.4 0.8<br />

-1<br />

1<br />

1<br />

a) b) c)<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

Z/a Z/a<br />

-0.6<br />

0.6<br />

0.2<br />

0<br />

-0.2<br />

-0.6<br />

0 1<br />

0<br />

0<br />

-1<br />

0 0.4 0.8<br />

0 0.4 0.8<br />

-1<br />

0 1<br />

r<br />

r<br />

(R-R 0 )/a<br />

Figure 1.44 – Simulation results of KBAE excitations by energetic particles for β H = 0.009. The top panel shows the case with<br />

no kinetic thermal ions, the bottom panel shows the one with kinetic thermal (core) ions where β ic =0.0128. Column a) is the<br />

ra<strong>di</strong>al mode structure, column b) is the frequency spectrum of the electrostatic component of the fluctuating em field, and<br />

column c) is the poloidal mode structure<br />

ion frequency gap but also <strong>di</strong>scretizing the BAE–SAW continuum. In that case, the <strong>di</strong>screte KBAEs are rea<strong>di</strong>ly<br />

excited by the EP drive.<br />

The extended hybrid MHD gyrokinetic model for XHMGC has been further generalized. In order to account<br />

for the finite parallel electric field due to parallel thermal electron pressure gra<strong>di</strong>ent, the parallel Ohm’s law is<br />

mo<strong>di</strong>fied by accounting for kinetic bulk plasma responses. Meanwhile, electron pressure gra<strong>di</strong>ent is added into<br />

the vorticity equation and finite parallel electric field is taken into account in the particle motion<br />

self–consistently. The further extended model for XHMGC allows us to confirm the theoretical pre<strong>di</strong>ctions –<br />

based on the generalized fishbone–like <strong>di</strong>spersion relation [1.56] – that the Alfvénic fluctuation is always the<br />

least damped among the kinetically mo<strong>di</strong>fied shear Alfvén and sound fluctuation branches and, thus, in<br />

general the experimentally most relevant one[1.62].<br />

Parametric form of equilibrium particle <strong>di</strong>stribution functions for implementations in HMGC<br />

The hybrid MHD gyrokinetic code HMGC and its extended version XHMGC [1.70] are capable of loa<strong>di</strong>ng<br />

a parametric form of equilibrium particle <strong>di</strong>stribution functions, given in the space of particle constants of<br />

motion. In this way is possible to use a numerically effective “delta–f scheme” without introducing any<br />

spurious effects and numerical noise caused by a prompt relaxation of the initial <strong>di</strong>stribution function. The<br />

parametric <strong>di</strong>stribution function adequately represents energetic particle populations in <strong>di</strong>fferent situations: α<br />

particles and supra–thermal particle tails produced by either minority ion cyclotron resonance heating (ICRH)<br />

or (negative) neutral beam injection ((N)NBI). When FOW effects are ignorable, the parametric <strong>di</strong>stribution<br />

function rea<strong>di</strong>ly reproduces the “slowing down” (SD) for αs, the anisotropic SD for (N)NBI and the<br />

bi–Maxwellian for ICRH minority heating. It is possible to choose parametric dependences to fit known<br />

profiles, such as temperature or density profiles, from experimental data or other simulation results. This<br />

<strong>di</strong>stribution function has been applied to simulate the behavior of energetic particles due to ICRH minority<br />

heating in FAST [1.71].<br />

Design of energetic particle equilibrium <strong>di</strong>stribution functions<br />

To the purpose of implementing an equilibrium particle <strong>di</strong>stribution function in more general con<strong>di</strong>tions than<br />

those described just above, a numerical method has been developed (in collaboration with the Naka Fusion<br />

Institute, JAEA), which allows particle simulations of toroidally confined plasmas to be initialized with a<br />

particle <strong>di</strong>stribution function F eq that owns the following properties: (i) having been constructed from<br />

unperturbed particle orbits, F eq is an exact equilibrium that properly takes into account the effect of magnetic


036<br />

progress report<br />

2010<br />

drifts and finite system size; (ii) chosen moments of f eq match given reference profiles as much as physical<br />

constraints permit; (iii) the process of designing the <strong>di</strong>stribution in velocity space is made largely independent<br />

of any spatial profile fitting. The method is particularly useful for simulations where magnetic drifts across<br />

magnetic flux surfaces are significant. In such cases, velocity and spatial coor<strong>di</strong>nates are intertwined and the<br />

above three properties are <strong>di</strong>fficult to be simultaneously obtained with analytical models. The new numerical<br />

method was implemented in a tool called VisualStart, which is written in Matlab and provides for interactive<br />

graphical user interfaces in order to assist the user with the design of a complete initial snapshot for<br />

MHD–kinetic hybrid codes.<br />

The above analytical and numerical methods will now be applied to represent more realistically and more<br />

accurately than before the energetic ion populations created by NBI and ICRH. Through the new <strong>di</strong>stribution<br />

functions, simulations of energetic–ion–driven instabilities will be carried out by using XHMGC [1.70] and<br />

applied in plasma con<strong>di</strong>tions that are relevant for burning plasma physics stu<strong>di</strong>es, such as those of FAST.<br />

A new model for self–organized critical dynamics, with implication of the fishbone–like<br />

instability cycle<br />

The phenomena of self–organized criticality (SOC) originally proposed by Bak, Tang, and Wiesenfeld [1.72]<br />

have been investigated in a new lattice model, dubbed dynamic polarization random walk (DPRW) model, in<br />

which the transported quantity is taken to be the electric charge of electrostatically interacting particles of<br />

<strong>di</strong>fferent kinds. For convenience, the transport problem is defined in a capacitor-like geometry as shown in<br />

figure 1.45.<br />

The model is motivated by the well–known problem [1.73] that, by increasing the probability of site<br />

occupancy, a lattice is brought to a critical point characterized by fractal geometry of the threshold<br />

percolation, i.e., self–similar <strong>di</strong>stribution of arbitrary large finite clusters, each presenting the same fractal<br />

geometry of the infinite cluster. This fractal geometry is made self–organized via mechanisms of random<br />

walk–like hopping of the lattice defects («holes») between the nearest-neighbor conducting sites. The<br />

concentration of the conducting sites, in its turn, is self–consistently controlled by the varying potential<br />

<strong>di</strong>fference on the capacitor. That means that the dynamical state of the lattice is coupled with the particle<br />

injection and loss processes. The system is shown to be fluctuating near the state of the threshold percolation<br />

in response to a small white-noise perturbation applied to the charged plate. The DPRW model gives critical<br />

exponents consistent with the results of numerical simulations of the tra<strong>di</strong>tional «sand–pile» SOC models<br />

[1.72,1.74,1.75], and stability properties, associated with the scaling of the control parameter versus <strong>di</strong>stance<br />

to criticality. It is found that relaxations to SOC of a slightly supercritical state are described by the Mittag-<br />

Leffler function, since this is the solution to the fractional relaxation equation [1.76], and not by a simple<br />

exponential function as for standard relaxation. The durations of relaxations events are power-law <strong>di</strong>stributed,<br />

with the <strong>di</strong>verging upper cut–off relaxation scale. The model belongs to the same universality class as the Bak,<br />

Tang, and Wiesenfeld sand–pile [1.72], and should be <strong>di</strong>stinguished from the <strong>di</strong>rected-percolation-based SOC<br />

models [1.77].<br />

One important result worth noticing is that the behavior of the DPRW system crucially depends on the<br />

strength of external forcing.<br />

Sub-critical: pp c<br />

Indeed, a self–organized state<br />

mimicking a pure SOC state only<br />

occurs in the limit of infinitesimal<br />

driving when the random–walk<br />

motions in the lattice are allowed<br />

-I<br />

to relax before input conducting<br />

sites are again introduced. This<br />

being not the case, the system is<br />

– Free charge (electron)<br />

– Polarization charge<br />

– Hole or lattice defect<br />

found to become unstable. The<br />

instability manifests itself as sharp<br />

perio<strong>di</strong>c bursts of the particle loss<br />

Figure 1.45 – DPRW model. Grey, blue, and azure particles show respectively the current in the ground circuit. The<br />

free charges, polarization charges, and holes. a) System below the percolation bursting mode is excited because<br />

point. Free charges are built by external forces on the capacitor's left plate. b) the dc conductivity of the lattice<br />

System slightly above the percolation point, with an illustration of hopping nonlinearly changes with the<br />

activities on the lattice. Adapted from ref. [1.79]


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

037<br />

driving strength. The instability is «resonant» in that the particle loss process is <strong>di</strong>rectly proportional to the<br />

electric current in the ground circuit. This «resonant» property <strong>di</strong>ctates a very specific nonlinear twist to the<br />

bursting dynamics, thus enabling to associate this instability of SOC with the «fishbone» instability in<br />

magnetic confinement systems with high–power beam injection [1.52] (the lattice occupancy per site<br />

corresponds to the effective resonant beam–particle normalized pressure within the q=1 surface; the<br />

percolation point corresponds to the mode excitation threshold; and the particle loss current in the ground<br />

circuit corresponds to the amplitude of fishbone). The transition to bursting dynamics signifies the increased<br />

role of global and nonlinear behaviors in the strongly driven DPRW system as compared to a pure SOC<br />

system. The results of the present study also suggest that the nonlinear science of fishbone [1.46] might be<br />

thought of as being connected with those properties generic to strongly-driven, interaction–dominated,<br />

thresholded dynamical systems such as the DPRW supercritical system rather than unique to toroidally<br />

confined fusion plasmas. An account of some of these investigations have been reported recently [1.78,1.79].<br />

The comprehension of fishbone–like instability of SOC when account is taken for the global character of the<br />

bursting dynamics suggests a type of mixed SOC–coherent behavior [1.80] in which the multi–scale features<br />

due to SOC can coexist along with the global or coherent features. One example of this coexistence is<br />

speculated [1.79] for the coupled solar wind-magnetosphere-ionosphere system. These theoretical fi<strong>di</strong>ngs are<br />

under way for being <strong>di</strong>scussed as part of the scientific rational of the ROY project [1.80], a state–of–the–art<br />

multi–satellite project in space research aiming to investigate the Earth's magnetosphere as a complex<br />

multi–scale system interacting with its solar wind drive.<br />

Asymptotic techniques in the study of the propagation of high frequency (lower hybrid range)<br />

electromagnetic waves<br />

The propagation and absorption of high frequency electromagnetic waves in laboratory plasma and in<br />

presence of an external magnetic field, is modeled by an integro-<strong>di</strong>fferential system of equations: the<br />

Maxwell–Vlasov system (in collaboration with IFTS– ZU). Starting from the Maxwell–Vlasov system, a<br />

simplified equation has been deduced that describes the propagation of an electrostatic pulse in cold plasmas<br />

and general magnetic equilibrium, which has been analytically stu<strong>di</strong>ed by means of a multiple spatial scale<br />

approach. This technique is strictly related with that <strong>di</strong>scussed earlier in [1.81], and, to the lowest order,<br />

reduces to the well–known “ballooning formalism” [1.82]. A simplified equation is derived and stu<strong>di</strong>ed for the<br />

scalar potential in the cold plasma limit, by applying the WKB asymptotic technique to describe the slow ra<strong>di</strong>al<br />

dependencies of the wave envelope, while the full–wave equation is considered along the magnetic field lines.<br />

This Ansatz can be entirely justified on the basis of spatial scale separation in the ra<strong>di</strong>al <strong>di</strong>rection and, thus,<br />

this approach could be viewed as a mixed WKB–full–wave technique.<br />

Analytical and numerical stu<strong>di</strong>es of the cold electromagnetic LH wave equation in the mode<br />

conversion regime<br />

The purpose of this study was to investigate the effect of mode conversion (n z<br />


038<br />

progress report<br />

2010<br />

non–integrability, due to the presence of two or more degrees of freedom, may lead to Hamiltonian chaos.<br />

These aspects have been stu<strong>di</strong>ed by producing phase portrait plots, Poincare maps, and computing numerically<br />

the Lyapounov exponents, thus elucidating some interesting features of the LH propagation in the external<br />

plasma.<br />

The propagation and absorption of lower hybrid waves in H–mode plasma with very sharp<br />

density gra<strong>di</strong>ent at the pedestal<br />

Flat density profiles in tokamak plasmas are characterized by a density rise at the plasma periphery, which may<br />

prevent LH waves from penetrating deeply into the center. The reasons may be the deviation of the ray<br />

trajectories toward the plasma edge or the lack of vali<strong>di</strong>ty of the linear optics approximation (WKB). In this<br />

work the wave equations has been solved in full wave limit, in order to analyze whether outward reflections<br />

take place. The results in<strong>di</strong>cate that, unless the density rise is a very sharp jump, the reflection is negligible and<br />

the linear WKB wave equations are a valid tool to describe the wave ray tracing. These trajectories result to<br />

be deviated across the density rise, but their deviation depends on the central density value and scarcely on the<br />

edge gra<strong>di</strong>ent strength.<br />

Tritium minority heating with mode conversion of fast waves<br />

A new ion–heating scenario in tokamak plasmas is proposed, based on cyclotron damping of IBWs by tritium<br />

minority at the first ion cyclotron harmonic (i.e. ω=2Ω cT<br />

). The IBWs are coupled by mode conversion of fast<br />

magneto–sonic waves (FMW) in a D–H(T) (tritium minority in hydrogen-deuterium) plasma. The mode<br />

conversion layer is located near the centre of the plasma column as well as the resonant layer of the tritium<br />

minority. A possible scenario for the JET tokamak [1.84], based on the present idea, has been analyzed by<br />

means of the numerical codes toroidal ion cyclotron (TORIC) & steady state Fokker Planck quasi linear<br />

(SSFPQL) [1.85,1.86]. As a result, Tritium ions are accelerated up to energies close to the peak value of the<br />

DT cross–section and a significant increase in Q has been found [1.87].<br />

∼<br />

ν z<br />

2000<br />

2.0<br />

1000<br />

0<br />

u<br />

0<br />

1.0<br />

2<br />

4<br />

x<br />

6<br />

8 0.0<br />

Figure 1.46 – Behavior of the vertical velocity ν ∼ z as a<br />

function of the <strong>di</strong>mensionless ra<strong>di</strong>al x and vertical u<br />

coor<strong>di</strong>nates<br />

Stellar winds or matter–jet seeds from <strong>di</strong>sk<br />

plasma configuration<br />

The profile of a thin <strong>di</strong>sk configuration was stu<strong>di</strong>ed<br />

[1.88] as described by an axisymmetric ideal MHD<br />

steady equilibrium (in collaboration with the University<br />

of Rome “La Sapienza” and ICRANet). The <strong>di</strong>sk was<br />

considered as a <strong>di</strong>fferentially rotating system dominated<br />

by the Keplerian term, but allowing for a non–zero ra<strong>di</strong>al<br />

and vertical matter flux. In this scheme, the steady state<br />

allows for the existence of local peaks for the vertical<br />

velocity ν ∼ z<br />

of the plasma particles (fig. 1.46), though it<br />

prevents the ra<strong>di</strong>al matter accretion rate from taking<br />

place. This ideal MHD scheme is therefore unable to<br />

solve the angular momentum–transport problem, but it is<br />

suggested that it provides for a mechanism for the<br />

generation of stellar winds or matter–jet seeds. A<br />

visco–resistive scenario has also been set up [1.89], which generalizes previous two–<strong>di</strong>mensional analyses by<br />

reconciling the ideal MHD coupling of the vertical and the ra<strong>di</strong>al equilibria within the <strong>di</strong>sk with the standard<br />

mechanism of the angular momentum transport, relying on <strong>di</strong>ssipative properties of the plasma configuration.<br />

1.4 JET Collaboration<br />

In October 2009, JET operations were suspended to start the installation of the new ITER like wall (ILW)<br />

using beryllium and tungsten as plasma facing components (PFC). The related shut–down is still continuing<br />

and the first plasma is now foreseen for the beginning of August 2011.


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

039<br />

<strong>ENEA</strong> Frascati scientists have participated in the analysis of the data gathered during the last campaigns and<br />

finalized journal papers and contribution to international conferences, such as EPS, SOFT, IAEA and others.<br />

On the basis of data taken during the last experimental campaigns, significant progress was made in terms of<br />

analysis, interpretation and <strong>di</strong>agnostic commissioning. Highlights regar<strong>di</strong>ng the main areas of interest are<br />

reported below.<br />

Pellet stu<strong>di</strong>es<br />

The analysis of pellet ablation and particle deposition experiments has been completed and presented at the<br />

2010 IAEA Conference [1.90]. Data show a clear evidence of ∇B drift effects in agreement with code<br />

simulations (fig. 1.47). These simulations were performed within the JINTRAC code suite by using JETTO as<br />

a core transport code and HPI2 for pellet ablation and ∇B drift effect calculations. In L–mode or moderately<br />

heated H–mode this effect seems to be weak. At high heating power instead, injection from the vertical high<br />

field side (VHFS) has proven to be much more effective than from low field side (LFS) in depositing particles<br />

beyond the pedestal. In the latter case,<br />

ablated particles are quickly lost due to a<br />

combination of ∇B drift and edge<br />

instabilities. The fuelling performance,<br />

although investigated only in a limited<br />

range of plasma and pellet parameters,<br />

seems to be promising for the capability of<br />

pellets to raise the density without<br />

increasing the neutral pressure in the main<br />

chamber. This latter feature is important<br />

for ITER, since it confirms that pellets are<br />

less deman<strong>di</strong>ng in terms of pumping<br />

capabilities.<br />

High beta operation<br />

Stability of high–beta advanced scenarios<br />

has been analyzed for a wide range of<br />

q–profiles and normalized beta values up<br />

to β N<br />

=4. Global n=1 instabilities limit the<br />

achievable β N<br />

or degrade confinement.<br />

Most recent results were presented at the<br />

2010 IAEA Conference [1.91]. Stability<br />

boundaries in terms of q min<br />

and pressure<br />

peaking have been determined. For<br />

relatively broad pressure profiles the limit<br />

decreases from β N<br />

=4 at q min<br />

=1 to β N<br />

=2<br />

at q min<br />

=3, while at fixed q min<br />

it decreases<br />

with increasing pressure peaking. Bursting<br />

and continuous n=1 instabilities have also<br />

been analyzed. A new form of instability<br />

that grows on typical resistive time-scales<br />

but has kink internal structure has been<br />

identified. This instability systematically<br />

occurs above the no–wall ideal stability<br />

limit as calculated for n=1 modes by the<br />

MISHKA code. The measured mode<br />

structure is in good agreement with<br />

eigenfunctions given by the code. An<br />

overview of the mode analysis results is<br />

given in figure 1.48 on a β N<br />

vs q min<br />

plane.<br />

Δn/Δn peak<br />

1.0<br />

0.6<br />

0.2<br />

JPN 77863 – LFS hybrid<br />

-0.2<br />

0 0.4<br />

r/a<br />

a) b)<br />

JPN 77864 – VHFS hybrid<br />

0.8 0 0.4 0.8<br />

r/a<br />

Figure 1.47 – Particle deposition code simulations (blue) show a clear<br />

effect of ∇B drift on pellets injected from a) the LFS, and b) VHFS into<br />

high power (∼21 MW) hybrid <strong>di</strong>scharges. Particles injected from LFS<br />

are rapidly <strong>di</strong>splaced outwards as compared to ablation (red) and<br />

leave the main plasma, while in the VHFS case they are shifted inwards,<br />

thus producing a significant deposition (black), as measured by the<br />

HRTS<br />

βN<br />

4<br />

3<br />

2<br />

1<br />

0.5 1.5 2.5<br />

q min<br />

no n=1<br />

Broad b.<br />

Chirping<br />

Disrupt.<br />

Cont.<br />

Figure 1.48 – Distribution of stability characteristics in the β N –q min<br />

<strong>di</strong>agram for MHD modes with toroidal number n=1. Circles and<br />

squares are taken at maximum β N in <strong>di</strong>scharges without any n=1 mode<br />

and with weak broadband n=1 activity respectively. Triangles<br />

represent <strong>di</strong>scharges with bursts of short–lived (10 ms) intense<br />

chirping modes, in particular downward pointing triangles represent<br />

<strong>di</strong>sruptive cases. Stars represent the onset of long–lived n=1 modes


040<br />

progress report<br />

2010<br />

2<br />

Pulse # 73744<br />

a)<br />

6<br />

S(μW/sr nm) Ipla (MA)<br />

1<br />

0<br />

0.4<br />

0.2<br />

0<br />

0<br />

4<br />

Time (s)<br />

Figure 1.49 – After a <strong>di</strong>sruption, in the absence of plasma, the<br />

extra light seen by the Thomson scattering detectors is thought<br />

to be due to the interaction between the laser pulses and dust<br />

particles later released by the wall. a) plasma current, b)<br />

average dust signal of the 4th spectral channel of every core<br />

spectrometer<br />

b)<br />

8<br />

P thr (MW)<br />

4<br />

2<br />

0<br />

0<br />

H e conc scan shots<br />

P thr, scal 08<br />

D references<br />

40 80<br />

H e concentration (%)<br />

Figure 1.50 – Power threshold (P thr ) obtained with NBI<br />

as function of helium concentration for both He and D<br />

reference <strong>di</strong>scharges at 1.7 MA/1.8 T. All the<br />

configurations had the same low δ≈0.25 shape, and<br />

densities variations 2.3–2.8×10 19 m –3<br />

Dust<br />

Ra<strong>di</strong>ation has been observed by the high resolution Thomson scattering (HRTS) system after plasma<br />

terminations, which reveals the presence of impurities along the beam path released by the wall during the<br />

<strong>di</strong>sruptive power quench, known as dust [1.92]. This ra<strong>di</strong>ation has been carefully analyzed and, due to its<br />

spectral features, seems not to be due to pure scattering but to a more complicated laser–matter interaction.<br />

The intensity is compatible with the expected <strong>di</strong>mension of dust grains and the temporal decay shows two<br />

timescales (fig. 1.49). Averaging the values of the peaks in the signal traces over all spectrometers, one can have<br />

a rough estimate of the dust content. The dust lasts for about 1.5 seconds after the <strong>di</strong>sruption. A preliminary<br />

<strong>di</strong>stribution of the signals has been obtained and compared with a compound Poisson <strong>di</strong>stribution.<br />

L to H mode transition<br />

Data taken during the 2009 JET helium campaign have been fully analyzed and presented at the 2010 EPS<br />

Conference [1.93]. L–H in helium has been observed as a transition to Type III ELMs with a small<br />

confinement improvement associated with a small edge pedestal. Helium concentration varied from 1 to 87%<br />

and was found to have little impact on the power threshold (fig. 1.50). This is in line with recent ASDEX–U<br />

stu<strong>di</strong>es, but in contrast with JET 2001 results, which showed that He plasmas had a 40% higher threshold than<br />

D equivalents. However, it should be noted that the 2001 comparison was performed at lower density<br />

(∼2.0×10 19 m –3 ) than the more recent data base (∼2.3–2.8×10 19 m –3 ). If a slope inversion of the density<br />

dependence were at play, the 2009 and the 2001 results might be reconciled. Unfortunately, helium data at low<br />

density are not available in the 2009 database. Although physics understan<strong>di</strong>ng still remains to be improved<br />

and further experiments will have to be carried out, recent results seem to encourage the helium choice for the<br />

non–nuclear phase of ITER.<br />

Safety factor profile determination<br />

Profiles of the safety factor are determined by the motional stark effect (MSE) <strong>di</strong>agnostic combined with<br />

equilibrium reconstruction. The positions of low–order rational surfaces q=m/n (from 2/1 to 4/3, m and n<br />

being the poloidal and toroidal mode numbers, respectively) have been systematically compared with the ones<br />

inferred from the frequency of MHD modes. The connection between mode frequency and rational surface<br />

location depends on the velocity of the magnetic island produced by the mode at the correspon<strong>di</strong>ng rational<br />

surface. A previous assumption of island propagation at the toroidal velocity of the carbon impurity resulted<br />

to be inconsistent. Much better agreement was found by assuming that the island rotates with the deuterium<br />

ions fluid; the latter was calculated by ra<strong>di</strong>al force balance from carbon toroidal rotation and ion temperature<br />

profiles neglecting poloidal rotation. If neoclassical carbon poloidal rotation is included in the force balance,


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

041<br />

the agreement between MSE and MHD mode locations remains good, whereas the agreement is spoiled if<br />

measured poloidal rotation is used. More investigation is needed to understand this <strong>di</strong>screpancy. For reversed<br />

profiles, uncertainties in q values near the axis are higher than those for monotonic profiles, although in some<br />

cases they are seen to be correspon<strong>di</strong>ng to experimental data from x–ray tomography and the observation of<br />

Alfvén Cascades [1.94].<br />

Upgrade of neutron profile monitor (KN3N)<br />

The performances of the new <strong>di</strong>gitizing system for the neutron profile monitor (NPM) has been assessed by<br />

means of the analysis of data collected during JET plasma <strong>di</strong>scharges [1.95]. The signals from the NPM<br />

NE213 scintillators are acquired by a set of five <strong>di</strong>gital pulse shape <strong>di</strong>scrimination (DPSD) boards, each one<br />

with 4 acquisition channels (20 channels in total: 19+1 spare) with 14 bit resolution and 200 MHz sampling<br />

rate. Each DPSD acquisition board is fully configurable: thanks to the ethernet port and the embedded Linux<br />

operating system integrated in the field programmable gate array (FPGA), it is possible to set the parameters<br />

of the acquisition, to poll the state of the system as well as to start/stop the acquisitions.<br />

The system has been demonstrated to be capable to provide simultaneous 2.5 (DD) and 14 MeV (DT) neutron<br />

count rates. An example is given figure 1.51 for line of sight #4 (<strong>di</strong>scharge #79698); the plot also shows<br />

neutrons due to fast ion tails (FAST), correspon<strong>di</strong>ng to the proton energy range 3.5–10 MeV. For the same<br />

<strong>di</strong>scharge, figure 1.52 shows the line–integrated neutron emission<br />

profiles for the DD and DT cases. Note the <strong>di</strong>fferent rise times of<br />

LOS#4 #79698<br />

the DD and DT profiles at 9.5 s and 10 s due to the triton slowing<br />

800<br />

down time.<br />

6×104<br />

Work on the implementation of the KN3N data acquisition and<br />

processing within the JET CODAS system has been started in 2010.<br />

Elaboration of JET programme for 2011<br />

The <strong>ENEA</strong>–Frascati team has also actively participated in the<br />

elaboration of the JET programme for 2011 by sen<strong>di</strong>ng its<br />

representatives to the main Planning Meetings held in Culham, and<br />

by joining many working group meetings from remote. A number<br />

of experiments have been proposed in view of the new wall<br />

con<strong>di</strong>tions, which are now in the process of being selected and<br />

rationalized in an executable time-line. Main areas are of interest<br />

include: current profile and recycling control to access hybrid and<br />

steady state regimes, pellet stu<strong>di</strong>es, detection and control of intrinsic<br />

impurities, bulk tungsten tile response to heat loads, impact of edge<br />

parameters on LHCD efficiency, threshold for the L to H–mode<br />

transition with Be/W versus carbon wall, dust detection following<br />

<strong>di</strong>sruptions, integration of MHD, MSE and polarimetry data for<br />

q–profile reconstruction.<br />

Coor<strong>di</strong>nation of other Italian partners<br />

<strong>ENEA</strong> has also coor<strong>di</strong>nated the contribution of other Italian<br />

partners to JET activity and taken an active part in their execution.<br />

During the shut–down, scientific papers have been produced, based<br />

on former Campaigns and also some enhancements have been<br />

carried on mainly in the field of plasma <strong>di</strong>agnostics (University of<br />

Rome Tor Vergata) and plasma control (CREATE Consortium).<br />

In the field of <strong>di</strong>agnostics, in collaboration with Tor Vergata Rome<br />

University, a detailed statistical analysis of the polarimetric<br />

measurements, acquired during the campaigns 2003–2009, has<br />

been performed [1.96] thus highlighting some calibration problems<br />

Counts DD (s–1)<br />

2×10 4<br />

0<br />

48<br />

DD<br />

DT<br />

DT<br />

52 56<br />

Time (s)<br />

400<br />

0<br />

Counts DT,FAST (s –1 )<br />

Figure 1.51 – Neutron count rates for DD,<br />

DT and FAST energy windows (pulse<br />

#79698)<br />

Counts/s<br />

Counts/s<br />

1×105<br />

6×10 4<br />

2×104<br />

0<br />

0<br />

400<br />

200<br />

49.5 s DD (1.8-3.5 MeV)<br />

50.0 s<br />

a)<br />

50.5 s<br />

53.0 s<br />

55.0 s<br />

#79698<br />

10 20<br />

Channel<br />

49.5 s<br />

DT (10-16 MeV)<br />

50.0 s<br />

b)<br />

50.5 s<br />

53.0 s<br />

55.0 s<br />

#79698<br />

0<br />

0 10<br />

Channel<br />

Figure 1.52 – Neutron profiles for pulse<br />

#79698: DD a), DT b)<br />

20


042<br />

progress report<br />

2010<br />

mainly related to the experimental data of the most recent campaigns (2008–2009), particularly those of the<br />

high current <strong>di</strong>scharges. During 2010 a new calibration algorithm [1.97] was developed and completely<br />

validated for offline analysis to the purpose of to overcoming this problem.<br />

Plasma control<br />

The plasma pontrol activity was carried out in collaboration with CREATE Consortium. Fusion relevant<br />

theoretical stu<strong>di</strong>es, tool development and technology stu<strong>di</strong>es were carried out in the framework of the general<br />

support to physics activities and underlying technology. A significant fraction of the activity has been addressed<br />

to the following fields:<br />

Modelling of resistive wall modes. The <strong>di</strong>spersion relation of resistive wall modes (RWM) has been derived<br />

when a cylindrical plasma circumvented by a thin resistive shell and an outer, non–conducting, ferromagnetic<br />

wall is considered [1.98]. It has been demonstrated that the resulting growth rate is always higher than that in<br />

the absence of any ferromagnetic materials, hence it always provides a destabilizing effect, which is consistent<br />

with previous results similarly obtained for somewhat <strong>di</strong>fferent arrangements. The growth rate increase does<br />

not depend on the plasma configuration but only on the poloidal mode number as well as on the physical<br />

and geometrical properties of the ferromagnetic shell. Several calculations have been made to verify these<br />

fin<strong>di</strong>ngs on the JET tokamak with the CREATE L code. Although the JET geometry is very <strong>di</strong>fferent from the<br />

simplified case treated analytically, the main qualitative conclusion is absolutely confirmed.<br />

Development of a real–time framework for data acquisition and control in fusion experiments. The CREATE<br />

group has contributed in the development of the MARTe [1.99]. MARTe is a modular real–time<br />

multiplatform C++ framework tailored at, but not restricted to, the development and deployment of control<br />

systems. This framework has been recently adopted to drive the vertical stabilization of the JET tokamak<br />

[1.100,1.101].<br />

Breakdown analysis. A modeling activity has been carried out by using a refined CREATE L state space model<br />

[1.102] in order to analyze the electromagnetic con<strong>di</strong>tions of JET breakdown, also for what concerns the<br />

possible impact of the new ra<strong>di</strong>al field system on plasma breakdown [1.103]. This work identified for the first<br />

time the ra<strong>di</strong>al field due to the up-down asymmetric gaps in the iron core and the relative influence on the<br />

field null.<br />

Current limit avoidance. The preliminary activity for the implementation of a current limit avoidance system<br />

within the existing architecture of the shape controller has been carried out [1.104]. In particular, the detailed<br />

design document and the Level–1 interface documents have been issued at the end of the year.<br />

Presentation of the main achievements of the PCU2 projects. In 2009 the PCU2 project was mainly focused<br />

on designing and commissioning the new vertical stabilization system of JET. Therefore, little time was<br />

de<strong>di</strong>cated to the preparation of the report, the metho<strong>di</strong>c and systematic analysis of the experimental results,<br />

and the presentation of the achievements to the scientific community. This has been effectively done in 2010,<br />

with the compilation of the final report, the presentation of the commissioning phase, and the illustration of<br />

the main achievements [1.105].<br />

References<br />

[1.1] N.J. Fisch, Phys. Rev. Letts 41, 873–876 (1978)<br />

[1.2] S. Bernabei et al., Phys. Rev. Letts 49, 1255–1258 (1982)<br />

[1.3] R. Cesario et al., Phys. Rev. Letts 92, 17, 175002 (2004)<br />

[1.4] R. Cesario et al., Nature Comm. 1(5),55 (2010)<br />

[1.5] R. Cesario et al., Plasma edge density and lower hybrid current drive in JET (Joint European Torus), submitted<br />

to Plasma Phys. Contr. Fusion<br />

[1.6] F. Zonca et al., Nucl Fusion 47, 1588 (2007)<br />

[1.7] C. Nguyen et al., Theoretical and experimental analysis of the destabilization of modes driven by fast particles<br />

in Tore-Supra, Procee<strong>di</strong>ngs of the 23rd IAEA Fusion Energy Conference (Daejon 2010), CN–180 – Paper<br />

EXS/P7–02 (2010)


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

043<br />

[1.8] P. Buratti et al., Nucl. Fusion 45, 1446 (2005)<br />

[1.9] A. Biancalani et al., Continuous spectrum of shear Alfvén waves inside magnetic islands, Procee<strong>di</strong>ngs of the<br />

37th EPS Conference on Plasma Physics (Dublin 2010), ECA Vol. 34A, P4.109 (2010)<br />

[1.10] J.W. Connor and R. J. Hastie, Nucl. Fusion 15, 415 (1975)<br />

[1.11] J.R. Martin–Solis, R. Sanchez and B. Esposito, Phys. Rev. Letts 105, 185002 (2010)<br />

[1.12] A. Tuccillo et al., Overview of FTU results, Procee<strong>di</strong>ngs of the 23rd IAEA Fusion Energy Conference (Daejon<br />

2010), CN–180 – Paper OV/4–2 (2010)<br />

[1.13] A. Romano et al., Rev. Sci. Instrum. 81, 10E523 (2010)<br />

[1.14] S. Dabagov, Physics–Uspekhi 46(10), 1053–1075 (2003)<br />

[1.15] D. Pacella et al., Polycapillary optics for soft imaging and tomography, submitted to Il Nuovo Cimento (2010)<br />

[1.16] X. Llopart et al., IEEE Trans. Nucl. Sci. 49(5), 2279–2283 (2002)<br />

[1.17] C. Castaldo, S. Ratynskaia et al., Nucl. Fusion 47, L5 (2007)<br />

[1.18] C. Castaldo et al., Nucl. Fusion 48, 015006 (2008)<br />

[1.19] C. Castaldo et al., Plasma Phys. Control. Fusion 52, 105003 (2010)<br />

[1.20] E. Giovannozzi et al ., Rev. Sci. Instrum. 81, 10E131 (2010)<br />

[1.21] B.J. Braams and C. H. Skinner, Characterisation of size, composition and origins of dust in fusion devices,<br />

Summary Report of the Second Research Coor<strong>di</strong>nation Meeting, INDC(NDS)-0578, IAEA November 2010,<br />

http://www-nds.iaea.org/reports–new/indc–reports/indc–nds/indc–nds–0578.pdf<br />

[1.22] C. Castaldo, Novel <strong>di</strong>agnostics for dust in space, laboratory and fusion plasmas, accepted for publication in<br />

Contrib. Plasma Phys.<br />

[1.23] V. Bobkov et al., Nucl. Fusion 50, 035004 (2010)<br />

[1.24] F. Braun, Antenna optimization by using finite element programs, Procee<strong>di</strong>ngs of the 16th Topical Conf. on<br />

Ra<strong>di</strong>o Frequency Power in Plasmas (Park City 2005), AIP Conf. Proc. Vol. 787, 238–241 (2005)<br />

[1.25] D. Milanesio et al., Mitigation of RF potentials by an appropriate antenna design using TOPICA, Presented at<br />

the 52nd Annual Meeting of the APS Division of Plasma Physics (Chicago 2010)<br />

[1.26] A. Biancalani, Shear Alfvén modes in the presence of a magnetic island, PhD Thesis, University of Pisa (2010)<br />

[1.27] A. Biancalani et al., Phys. Rev. Letts 105, 095002 (2010)<br />

[1.28] A. Biancalani et al., Phys. Plasmas 17, 122106 (2010)<br />

[1.29] R. Betti and J.P. Freidberg, Phys. Fluids B3, 1865 (1991)<br />

[1.30] A. Biancalani et al., 2D continuous spectrum of shear Alfvén waves in the presence of a magnetic island,<br />

accepted for publication in Plasma Phys. Control. Fusion<br />

[1.31] A. Botrugno et al., Comparison between BAE observations at FTU and theoretical models, Procee<strong>di</strong>ngs of the<br />

37th EPS Conference on Plasma Physics (Dublin 2010), ECA Vol. 34A, P4.110 (2010)<br />

[1.32] L. Chen, Phys. Plasmas 1, 1519 (1994)<br />

[1.33] H. Grad, Phys. Today 22, 34 (1969)<br />

[1.34] A. Hasegawa and L. Chen, Phys. Rev. Letts 32, 454 (1974)<br />

[1.35] L. Chen and A. Hasegawa, Phys. Fluids 17, 1399 (1974)<br />

[1.36] F. Zonca and L. Chen, Phys. Rev. Letts 68, 592 (1992)<br />

[1.37] N. Winsor, J. Johnson and J.M. Dawson, Phys. Fluids 11, 2448 (1968)<br />

[1.38] X. Garbet et al., Theory of fusion plasmas, Ed. by J.W. Connor et al , AIP Conference Procee<strong>di</strong>ngs 871, 342<br />

(2006)<br />

[1.39] H.L. Berk et al, Nucl. Fusion 46, S888 (2006)<br />

[1.40] R. Nazikian et al, Phys. Rev. Letts 101, 185001 (2008)<br />

[1.41] G. Fu, Phys. Rev. Letts 101, 185002 (2008)<br />

[1.42] V.B. Lebedev et al, Phys. Plasmas 3, 3023 (1996)<br />

[1.43] S.V. Novakovskii et al, Phys. Plasmas 4, 4272 (1997)<br />

[1.44] H. Sugama and T.-H. Watanabe, Phys. Plasmas 13, 012501 (2006)<br />

[1.45] Z. Gao et al., Phys. Plasmas 13, 100702 (2006)<br />

[1.46] L. Chen and F. Zonca, Nucl. Fusion 47, S727 (2007)<br />

[1.47] F. Zonca and L. Chen, Europhys. Lett. 83, 35001 (2008)<br />

[1.48] F. Zonca, L. Chen and Z. Qiu, Kinetic theory of Geodesic Acoustic Modes: ra<strong>di</strong>al structures and nonlinear<br />

excitations, Procee<strong>di</strong>ngs 22nd IAEA Fusion Energy Conference (Geneva 2008) CD-ROM file TH/P3-7<br />

[1.49] F. Zonca and L. Chen, Phys. Plasmas 7, 4600 (2000)<br />

[1.50] Z. Qiu, F. Zonca and L. Chen, Plasma Phys. Control. Fusion 52, 095003 (2010)


044<br />

progress report<br />

2010<br />

[1.51] R. Nazikian, private communication (2009)<br />

[1.52] L. Chen, R.B. White and M.N. Rosenbluth, Phys. Rev. Lett. 52, 1122 (1984)<br />

[1.53] S.T. Tsai and L. Chen, Phys. Fluids B 5, 3284 (1993)<br />

[1.54] L. Chen, Phys. Plasmas 1, 1519 (1994)<br />

[1.55] F. Zonca and L. Chen, Plasma Phys. Control. Fusion 38, 2011 (1996)<br />

[1.56] F. Zonca and L. Chen, Plasma Phys. Control. Fusion 48, 537 (2006)<br />

[1.57] C. Nguyen, X. Garbet and A.I. Smolyakov, Phys. Plasmas 15, 112502 (2008)<br />

[1.58] F. Zonca et al, Nucl. Fusion 49, 085009 (2009)<br />

[1.59] I. Chavdarovski and F. Zonca, Plasma Phys. Control. Fusion 51, 115001 (2009)<br />

[1.60] Ph. Lauber et al., Plasma Phys. Control. Fusion 51, 124009 (2009)<br />

[1.61] N.N. Gorelenkov et al., Phys. Plasmas 16, 056107 (2009)<br />

[1.62] F. Zonca et al., J. Phys.: Conf. Ser. 260, 012022 (2010)<br />

[1.63] X. Wang, F. Zonca and L. Chen, Plasma Phys. Control. Fusion 52, 115005 (2010)<br />

[1.64] S. Briguglio et al., Phys. Plasmas 2, 3711 (1995)<br />

[1.65] Y. Todo et al., Phys. Plasmas 12, 012503 (2005)<br />

[1.66] D.A. Spong, B.A. Carreras, and C.L. Hedrick, Phys. Plasmas 1, 150 (1994)<br />

[1.67] A. Bondeson, G. Vlad and H. Luetjens, Computation of resistive instabilities in toroidal plasmas, Procee<strong>di</strong>ngs<br />

of the IAEA Technical Committee Meeting on Advances in Simulation and Modeling of Thermonuclear Plasmas<br />

(Montreal 1992), pp. 306–315<br />

[1.68] G. Vlad, et al., Toward a new hybrid MHD gyrokinetic code: Progresses and perspectives. Presented at the 11th<br />

IAEA Technical Meeting on Energetic Particles in Magnetic Confinement Systems (Kyiv 2009), paper P–25<br />

[1.69] H. Luetjens, A. Bondeson and A. Roy, Comput. Phys. Commun. 69, 287 (1992)<br />

[1.70] X. Wang, et al., An extended hybrid magnetohydrodynamics gyrokinetic model for numerical simulation of<br />

shear Alfvén waves in burning plasmas, accepted for publication in Phys. Plasmas<br />

[1.71] A. Car<strong>di</strong>nali et al., Energetic particle physics in FAST H–mode scenario with combined NNBI and ICRH,<br />

Procee<strong>di</strong>ngs of the 23rd IAEA Fusion Energy Conference (Daejon 2010), CN–180 – Paper THW/P7–04 (2010)<br />

[1.72] P. Bak, C. Tang, and K. Wiesenfeld, Phys. Rev. Lett. 59, 381 (1987)<br />

[1.73] D. Stauffer, Phys. Rep. 54, 1 (1979)<br />

[1.74] C. Tang and P. Bak, Phys. Rev. Lett. 60, 2347 (1988)<br />

[1.75] Y.-C. Zhang, Phys. Rev. Lett. 63, 470 (1989)<br />

[1.76] R. Metzler and J. Klafter, Phys. Rep. 339, 1 (2000)<br />

[1.77] S. Maslov and Y.-C. Zhang, Physica A 223, 1 (1996)<br />

[1.78] A.V. Milovanov, Europhys. Lett. 89, 60004 (2010)<br />

[1.79] A. V. Milovanov, Dynamic polarization random walk model and fishbone–like instability for self–organized critical<br />

systems, submitted to New J. Phys. (2010)<br />

[1.80] S. Savin et al., A multiscale magnetospheric mission, to appear in Planet. Space Sci. (2010). doi:<br />

10.1016/j.pss.2010.05.001


magnetic confinement (cont’d.)<br />

progress report<br />

2010<br />

045<br />

[1.81] F. Zonca and L. Chen, Phys. Fluids B 5, 3668, (1993)<br />

[1.82] J.W. Connor, R.J. Hastie and J.B. Taylor, Phys. Rev. Lett. 40, 396 (1978)<br />

[1.83] A. Car<strong>di</strong>nali and V. Fusco, J. Phys.: Conf. Ser. 260, 012007 (2010)<br />

[1.84] J. Wesson, JET–Report (99) 13, Oxford, (1999)<br />

[1.85] M. Brambilla, Nucl. Fusion 34, 1121 (1994)<br />

[1.86] M. Brambilla, Plasma Phys. Control. Fusion 41, 1 (1999)<br />

[1.87] C. Castaldo and A Car<strong>di</strong>nali, Phys. Plasmas 17, 072513 (2010)<br />

[1.88] G. Montani and N. Carlevaro, Phys. Rev. E 82, 025402(R) (2010)<br />

[1.89] G. Montani and R. Benini, Gen. Rel. Grav., 1–20 (2010), DOI:10.1007/s10714–010–1038–9<br />

[1.90] D. Frigione et al. Particle deposition, transport and fuelling in pellet injection experiments at JET, Procee<strong>di</strong>ngs<br />

of the 23rd IAEA Fusion Energy Conference (Daejon 2010), CN–180 – Paper EXC/P4-05 (2010)<br />

[1.91] P. Buratti et al., Kink instabilities in high–beta JET advanced scenarios, Procee<strong>di</strong>ngs of the 23rd IAEA Fusion<br />

Energy Conference (Daejon 2010), CN–180 – Paper EXS/P5-02 (2010)<br />

[1.92] E. Giovannozzi et al., Detection of dust on JET with the high resolution Thomson scattering systems,<br />

Procee<strong>di</strong>ngs of the 18th High Temperature Plasma Diagnostics, (Wildwood 2010) Rev. Sci. Instrum. 81,<br />

10E131(1-3) (2010)<br />

[1.93] G. Calabrò et al., H–mode threshold stu<strong>di</strong>es in helium–4 JET plasmas, Procee<strong>di</strong>ngs of the 37th EPS Conference<br />

on Plasma Physics (Dublin 2010), ECA Vol. 34A, P5.176 (2010)<br />

[1.94] R. De Angelis et al., Determination of q profiles in JET by consistency of motional stark effect and MHD mode<br />

localization, Procee<strong>di</strong>ngs of the 23rd IAEA Fusion Energy Conference (Daejon 2010), CN–180 – Paper<br />

EXS/P2–03 (2010)<br />

[1.95] M. Riva et al. , The new <strong>di</strong>gital electronics for the JET neutron profile monitor: performances and first<br />

experimental results, Presented at the 26th Symposium on Fusion Technology (SOFT) (Porto 2010), to appear<br />

in Fusion Eng. Des.<br />

[1.96] M. Gelfusa et al., Measurement Sci. Technol. 21, 115704 (2010)<br />

[1.97] M. Gelfusa et al., Rev. Sci. Instrum. 81, 053507 (2010)<br />

[1.98] V.D. Pustovitov and F. Villone, Plasma Phys. Control. Fusion 52, 065010(12pp) (2010<br />

[1.99] C. Neto et al., IEEE Trans. Nucl. Sci. 57, 2, 479–486 (2010)<br />

[1.100] T. Bellizio et al., IEEE Trans. Plasma Sci. 38, 9, 2465–2473, (2010)<br />

[1.101] F. Sartori et al., Fusion Eng. Des. 85, 3-4, 438–442, (2010)<br />

[1.102] R. Albanese et al., Int. J. Appl. Electromag. Mech. 33, 533–540, (2010)<br />

[1.103] F. Maviglia et al., Electromagnetic analysis of breakdown con<strong>di</strong>tions in JET, Presented at the 26th Symposium<br />

on Fusion Technology (SOFT) (Porto 2010), to appear in Fusion Eng. Des.<br />

[1.104] G. Varano, et al., Performance assessment of a dynamic current allocator for the JET eXtreme shape controller,<br />

Presented at the 26th Symposium on Fusion Technology (SOFT) (Porto 2010), to appear in Fusion Eng. Des.<br />

[1.105] L. Zabeo et al., Fusion Eng. Des. 85, 3–4, 374–377 (2010)


046<br />

progress report<br />

2010<br />

chapter 2<br />

fusionadvancedstu<strong>di</strong>estorus<br />

It is presently widely accepted that a successful exploitation of ITER (“the way” in Latin) and a reliable as well<br />

as early design of demonstration/prototype reactor (DEMO) needs a strong accompanying program. Along<br />

this roadmap, a key role should be played by the so–called “Satellite Experiments”: Japan Tokamak 60 Super<br />

Advanced (JT–60SA) [2.1] and possibly Fusion Advanced Stu<strong>di</strong>es Torus (FAST) [2.2]. The two proposals are<br />

complementary with each other and hold the capability of accessing overlapping regions in the operational<br />

space; this may allow scientific achievements and experimental results to be compared. The primary aim of<br />

FAST is studying integrated plasma scenarios to the broadest possible extent.<br />

a) Plasma wall (PW) problems that ITER is expected to face, with an outlook on possible scenarios of<br />

relevance to DEMO; consequently, a large power load is foreseen (P/R∼22 MW/m –P/R∼12 MW/m),<br />

with actively cooled <strong>di</strong>vertor and first wall (FW) in full tungsten; in ad<strong>di</strong>tion, the very high operational<br />

density ( up to ∼ 6×10 20 m –3 ) will allow for experiments with high density and ra<strong>di</strong>ative plasma edge<br />

(up to ∼90%) even at low collisionality, as in ITER and unlike in other devices.<br />

b) ITER and DEMO will necessarily tackle severe operational problems, such as the presence of large edge<br />

localized modes (ELMs) (and the need of mitigating them), and the necessity of completely integrated<br />

plasma control tools; FAST will have very large ELMs (up to few MJ) and a complete set of systems to<br />

control the plasma operations in an integrated environment.<br />

c) Burning plasma stability and mutual feedbacks between thermal plasma and energetic particle populations<br />

are among the most interesting and unexplored physics aspects in view of ITER and, more importantly,<br />

DEMO. The possibility of performing ITER–relevant integrated experiments in satellites machines relies<br />

on the similarity argument based on the existence of three <strong>di</strong>mensionless parameters: ρ ∗ , β and ν ∗ [2.3]<br />

and in the so called “weak scaling” [2.2].


fusion advanced stu<strong>di</strong>es torus (cont’d.)<br />

progress report<br />

2010<br />

047<br />

2.2 Physics<br />

Transport simulations<br />

Table 2.I shows the main FAST operating scenarios foreseen, which should cover all the ITER scenarios and<br />

should be capable to address some of the pre<strong>di</strong>ctable DEMO necessities. Several <strong>di</strong>fferent core transport<br />

models have been used to simulate the FAST reference scenario, some of them based on first principle<br />

(Weiland and GLF23) and some on semi–empirical models (mixed Bohm–gyroBohm (BgB) and critical<br />

gra<strong>di</strong>ent model (CGM)).<br />

In these simulations the density profile has been<br />

assumed to be either flat (as it usually happens in the<br />

present H–modes) or peaked (as scaled by the<br />

present database for the FAST low collisionality<br />

case); in the case of simulations in which the plasma<br />

density is left to evolve (as, e.g. bu using the GLF23<br />

transport model), it results to be peaked. The<br />

simulations have been carried out by using the<br />

JETTO code; for ion cyclotron resonance heating<br />

(ICRH) heating profiles we have either used the<br />

PION code called self–consistenly by JETTO or by<br />

TORIC that is run outside JETTO and requires a<br />

few iterations. The final result is that all models<br />

pre<strong>di</strong>ct about the same electron temperature, but<br />

there is a larger range of variation in the T i<br />

profiles.<br />

Table 2.I – Operating scenarios<br />

In particular a careful attention has been devoted to Q 0.65 1.5 0.32 0.06<br />

studying the alternative scenario where only 15 MW t <strong>di</strong>scharge (s) 20 13 55 170<br />

ICRH are used together with 15 MW electron<br />

t flat–top (s) 13 2 45 160<br />

cyclotron resonance heating (ECRH) at 170 GHz.<br />

I<br />

The ECRH heating profiles have been provided by NI /I p (%) 15 15 60 >100<br />

the GRAY code, that requires iterations with<br />

JETTO. In this scenario the ICRH has been<br />

P ADD (MW) 30 40 40 40<br />

reduced up to the minimum level sufficient to generate a β H<br />

∼1%. Since the ECRH resonance is at 6.1 T,<br />

B T<br />

=6.0 T and I p<br />

=5.5 MA were used for this simulation; however, as a consequence of the Shafranov shift, the<br />

actual experiment could be planned at B T<br />

=6.7 T with a plasma current of around 6.0MA. In figure 2.1 the<br />

electrons and ions temperature, as pre<strong>di</strong>cted by using the <strong>di</strong>fferent models, are shown for the case with only<br />

ICRH and for the case with ICRH+ECRH. In the latter case the electron temperature always remains higher<br />

than the ion temperature (T e<br />

(0)∼15 keV, T i<br />

(0)∼9 keV). Although the ECRH deposition has been spread out<br />

on Δρ∼0.2, the fact that T e<br />

>T i<br />

can be justified by the much larger input power density on the electrons when<br />

FAST<br />

H–mode<br />

reference<br />

HMR<br />

H–mode<br />

extreme<br />

HME<br />

AT<br />

Full<br />

NICD<br />

I p (MA) 6.5 8.0 3.5 2<br />

q 95 3 2.6 5 5<br />

B T (T) 7.5 8.5 6 3.5<br />

H 98 1 1 1.2 1.2<br />

(m -3 ) 2 5 1.4 1<br />

β N 1.3 1.7 2.2 3.4<br />

τ E (s) 0.4 0.65 0.20 0.10<br />

τ res (s) 5.5 5 3 2÷5<br />

T 0 (keV) 13.0 9.0 12 7.5


048<br />

progress report<br />

2010<br />

T(eV)<br />

ICRH BgB<br />

ICRH W<br />

ICRH GLF<br />

ICRH CGM (chisi=2)<br />

ICRH CGM (chisi=4)<br />

ECRH+ICRH BgB<br />

ECRH+ICRH W<br />

ECRH+ICRH GLF<br />

ECRH+ICRH CGM (chisi=2)<br />

ECRH+ICRH CGM (chisi=4)<br />

ICRH BgB<br />

ICRH W<br />

ICRH GLF<br />

ICRH CGM (chisi=2)<br />

ICRH CGM (chisi=4)<br />

ECRH+ICRH BgB<br />

ECRH+ICRH W<br />

ECRH+ICRH GLF<br />

ECRH+ICRH CGM (chisi=2)<br />

ECRH+ICRH CGM (chisi=4)<br />

5000<br />

T e<br />

n e<br />

1×10 4 2×10 20<br />

T i<br />

6×10 20<br />

4×10 20<br />

n e (m –3 )<br />

ωφ(rad/s)<br />

1×10 5<br />

8×10 4<br />

6×10 4<br />

6×10 4<br />

n e<br />

v f<br />

4.5×10 20<br />

1.5×10 20<br />

4×10 4 3×10 20<br />

n e (m –3 )<br />

2×10 4 0.4 0.8 0 0.4 0.8<br />

0<br />

0<br />

ρ<br />

ρ<br />

Figure 2.1 – Ion and electron temperature and density profiles shown<br />

for the case of ICRH +ECRH (full line) and full ICRH (dotted line). Red<br />

lines are for old BgB, blue for Weiland, black for GLF23 and green for<br />

CGM. The assigned density profile is shown with dashed line<br />

2×10 4 0<br />

0<br />

0.4 ρ<br />

0.8<br />

Figure 2.2 – Rotation profile for NICD scenario<br />

compared to the ions one. This causes a negative loop to take place, where higher T e<br />

/T i<br />

decreases the ion<br />

temperature gra<strong>di</strong>ent (ITG) micro instabilities threshold, with consequent colder ions and not significantly<br />

hotter electrons than the full ICRH case.<br />

As shown in table 2.I the non inductive current driven (NICD) scenario has, in principle, the unique capability<br />

of studying a full non inductive regime at high β N<br />

, with a reactor relevant FW in tungsten. However, FAST<br />

will only have a small input of external momentum (like ITER) and only in the framework of the negative<br />

neutral beam injection (NNBI) scenarios. From recent experimental results it seems that the toroidal rotation<br />

plays a key role in achieving improved ion core confinement, not only through the well–known threshold up<br />

shift, but through a significant reduction of the ion stiffness. The rotation has been included in the simulations<br />

by modeling the momentum transport with physical assumptions consistent with recent theoretical<br />

developments. Due to the inward pinch, core rotation in FAST can be driven by intrinsic rotation edge sources.<br />

Given the present lack of understan<strong>di</strong>ng and the theory–based pre<strong>di</strong>ctive capability on intrinsic rotation, we<br />

have assumed for FAST an edge rotation value ω φ<br />

=30 krad/s. Considering the high intrinsic rotation values<br />

measured in C–MOD, which is a high field compact machine conceptually similar to FAST, it may still be<br />

legitimate to assume an edge rotation value as pre<strong>di</strong>cted by the existing C–MOD driven empirical scaling. The<br />

NICD scenario, with I p<br />

=2 MA, has been simulated by using the BgB model, without inclu<strong>di</strong>ng any torque<br />

source and by ad<strong>di</strong>ng 4 MW of LHCD at 5 GHz (n <br />

=2.3). In figure 2.2 the obtained/used rotation profile is<br />

shown. An ion temperature profile with an internal transport barrier (ITB)–like gra<strong>di</strong>ent, around ρ∼0.5÷0.6,<br />

has been obtained with a reversed q profile (q min<br />

∼2). The ion and electron temperature are very close with<br />

T i0<br />

∼20 keV, T e0<br />

∼15 KeV and with a density n e0<br />

∼2×10 20 m –3 . These parameters have to be regarded as<br />

overestimated due to the simplistic assumptions of the BgB model.<br />

Energetic particle physics in H–mode scenario with combined NNBI and ICRH<br />

The combination of ICRH+NNBI in FAST allows the generation of fast ion populations to occur with<br />

<strong>di</strong>fferent velocity space anisotropy and ra<strong>di</strong>al profiles. These energetic ion populations can excite meso–scale<br />

fluctuations with the same characteristics as those expected in reactor relevant con<strong>di</strong>tions and, for this reason,<br />

FAST can address a number of important burning plasma physics issues. Numerical simulation and modeling<br />

of energetic particle physics are based on the use of various transport codes that are iteratively coupled with<br />

a bi–<strong>di</strong>mensional full wave–quasi–linear solver for ICRH, which also includes the solution of the<br />

Fokker–Planck equation for NNBI–plasma interactions. Self–consistent profiles evolution is obtained by the<br />

suite of codes CRONOS with combined ICRH/NNBI heating. The ICRH frequency is in the range<br />

80–85 MHz and the NNBI energy from 0.7 to 1 MeV depen<strong>di</strong>ng on species (hydrogen or deuterium). A<br />

parametric study of the normalized supra-thermal population pressure β hot<br />

is being presented here and<br />

<strong>di</strong>scussed in terms of the RF+NBI power deposition profiles with various minority concentrations ( 3 He 1–3%).<br />

The value of β hot<br />

as well as the energetic particle <strong>di</strong>stribution functions can be used as an initial con<strong>di</strong>tion for<br />

numerical simulation stu<strong>di</strong>es, thus investigating the destabilization and saturation of fast ion driven Alfvénic


fusion advanced stu<strong>di</strong>es torus (cont’d.)<br />

progress report<br />

2010<br />

049<br />

ω/ωA0<br />

1<br />

0.5<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

ω/ω A0<br />

1<br />

0.5<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

0.008<br />

β hot⊥<br />

0.004<br />

Equil.<br />

n=8<br />

n=16<br />

0.2<br />

0.2<br />

0<br />

0 0<br />

0 0<br />

0 0.4 0.8 0 0.4 0.8 0<br />

ρ pol<br />

ρ pol<br />

0.4 0.8<br />

ρ pol<br />

Figure 2.3 – a) Intensity contour plot (of the electrostatic component of the fluctuating em field) of the n=8 Alfvénic mode in<br />

the space of normalized frequency and ra<strong>di</strong>al position. The shear Alfvén continuous spectrum for n=8 is in<strong>di</strong>cated by the black<br />

solid line; b) Intensity contour plot of the n=16 Alfvénic mode in the space of normalized frequency and ra<strong>di</strong>al position. The<br />

shear Alfvén continuous spectrum for n=16 is in<strong>di</strong>cated by the black solid line; c) Effect of n=8 and n=16 saturated EPM on the<br />

β hot⊥ ra<strong>di</strong>al profile<br />

Figure 2.4 – One of the <strong>di</strong>vertor geometries<br />

used for the SOL/edge simulations with<br />

EDGE2D/EIRENE<br />

modes by means of a recently extended version of the hybrid<br />

-1.30<br />

Pump B<br />

FAST <strong>di</strong>vertor n. 4<br />

magnetohydrodynamic gyrokinetic code (HMGC) [2.4],<br />

which is able to simultaneously handle two generic initial<br />

-1.40<br />

particle <strong>di</strong>stribution functions in the space of particle<br />

1.1 1.3 1.5 1.7<br />

constants of motion. The crucial role played by ra<strong>di</strong>al<br />

Major ra<strong>di</strong>us R (m)<br />

non–uniformities and by the shear Alfvén continuous<br />

spectrum, shown as solid lines in figures 2.3a and 2.3b, is<br />

consistent with the theoretical framework <strong>di</strong>scussed in [2.5,2.6]. The effect of n=8 and n=16 saturated EPM<br />

on the β hot⊥<br />

ra<strong>di</strong>al profile, shown in figure 2.3c, suggests that significant ra<strong>di</strong>al re<strong>di</strong>stributions of energetic<br />

particle are expected with limited global losses.<br />

Heights z(m)<br />

-1<br />

-1.10<br />

-1.20<br />

Pump A<br />

Plasma–wall interaction activities and optimization of the <strong>di</strong>vertor geometry<br />

The modelling of the FAST scrape–off layer (SOL)/edge plasma with the software package EDGE2D +<br />

EIRENE was carried out in 2010. Simulations have been run for the basic H–mode scenario: <strong>di</strong>fferent<br />

preliminary <strong>di</strong>vertor designs (fig. 2.4) have been examined by varying the density at the separatrix over the<br />

range n sep<br />

=0.7–1.0×10 20 m –3 [2.7]. The input power into the SOL has been set to 20 or 16 MW and no<br />

impurity see<strong>di</strong>ng was allowed. Besides the importance of an as shallow as allowed strike angle of the separatrix<br />

on the <strong>di</strong>vertor target, simulations highlight that significant detachment is attained only if the <strong>di</strong>vertor<br />

geometry and pump location are optimized to allow the formation of a consistent neutral cloud close to the<br />

strike point. At the lower separatrix densities the help of strongly ra<strong>di</strong>ating impurities would appear to be<br />

unavoidable.<br />

Diagnostics<br />

A first assessment of the extent to which the 3 He fast ion population can be <strong>di</strong>agnosed in FAST with a set of<br />

de<strong>di</strong>cated <strong>di</strong>agnostics has been performed [2.8], in order to show the capabilities of FAST in studying fast ion<br />

physics in con<strong>di</strong>tions relevant to a burning plasma. These energetic confined fast particles, with <strong>di</strong>mensionless<br />

parameters (normalized Larmor ra<strong>di</strong>us and plasma pressure) close to those of fusion-born alphas in ITER,<br />

will be produced in deuterium FAST plasmas by means of 30 MW ICRH minority heating. Neutron emission<br />

spectroscopy (NES), gamma ray spectroscopy (GRS) and collective Thomson scattering (CTS) <strong>di</strong>agnostics have<br />

been reviewed with a description of the state–of–the–art hardware and a preliminary analysis of the required<br />

lines of sight.<br />

Taking as an input the spatially resolved numerical simulations of the energy <strong>di</strong>stribution of ICRH accelerated<br />

particles, the correspon<strong>di</strong>ng spectra observed by the set of <strong>di</strong>agnostics have been simulated for specified lines


050<br />

progress report<br />

2010<br />

of observation and the observables related to changes in the tails of the fast ion energy <strong>di</strong>stribution have been<br />

determined and stu<strong>di</strong>ed. As for NES, the neutron emission (from the fusion reaction) energy spectrum reflects<br />

the energy <strong>di</strong>stribution of the deuteron population with the possible suprathermal components caused, for<br />

instance, by external heating. The GRS measured gamma ray emission spectra, from reactions between fast<br />

ions and impurities, allow <strong>di</strong>fferent information to be extracted: fast ions excee<strong>di</strong>ng the threshold energies of<br />

the reactions (by the identification of characteristic gamma ray peaks), combined fast ion density, temperature<br />

and impurity concentration (by peak intensities), fast ion temperature (by doppler broadening of the emission<br />

lines observed). At last, in CTS the doppler broadened scattered ra<strong>di</strong>ation provides space and time resolved<br />

information on the velocity <strong>di</strong>stribution of the plasma ions, inclu<strong>di</strong>ng the fast–ion population generated by<br />

ICRH. The detailed characterization of the fast particles dynamics poses deman<strong>di</strong>ng requirements since all<br />

the relevant plasma parameters should be ideally measured with spatial resolution close to the fast particles<br />

Larmor ra<strong>di</strong>us (of the order of 6 cm) and time resolution of the order of the interaction time of Alfvén modes<br />

with the fast particles (of the order of 30 ms) in the FAST H–mode reference scenario.<br />

The results of the analysis, based on numerical simulations of the spatial and energetic particle <strong>di</strong>stribution<br />

function of the ICRH accelerated minority 3 He ions, have shown that NES and GRS measurements can<br />

provide information on the anisotropy of the fast 3 He population and a measurement of its effective tail<br />

temperature, with time resolutions in the range 20–100 ms, and that the proposed CTS <strong>di</strong>agnostics can<br />

measure the fast ion parallel and perpen<strong>di</strong>cular temperature with a spatial resolution of 5–10 cm and a time<br />

resolution of 10 ms.<br />

2.3 Design Description<br />

The FAST project significantly advanced in the year 2010 [2.9] as for load assembly design, vacuum vessel<br />

and plasma facing components (fig. 2.5), with close attention to the remote maintenance issues. Extensive<br />

stu<strong>di</strong>es were carried out to investigate several <strong>di</strong>vertor design options.<br />

Divertor design<br />

The <strong>di</strong>vertor optimization of the <strong>di</strong>vertor from the physics and engineering point of view significantly<br />

advanced in 2010; at the same time, a whole <strong>di</strong>vertor design has been completed [2.10], able to withstand a<br />

power load up to 20 MW m –2 by using W monoblocks tiles [2.11,2.12]. Further stu<strong>di</strong>es will be carried out to<br />

complete the optimization in the next year.<br />

The <strong>di</strong>vertor, as currently designed, is composed by a cassette body (CB) that supports all the plasma facing<br />

components (PFC). The cassette body routs the water coolant and is mounted onto the vacuum vessel inboard<br />

and outboard rails via a mechanical locking system. Each<br />

<strong>di</strong>vertor module spans over 5 degrees for a total of 72<br />

modules in the whole tokamak and each module is made of<br />

6 rows of W monoblocks, in<strong>di</strong>vidually cooled by pressurized<br />

water flowing in CuCrZr pipes, 12 mm <strong>di</strong>ameter wide. The<br />

dome geometry is provided with a large opening in front of<br />

the strike zones in order to allow neutrals to flow into the<br />

private flux region and to be removed from there by pumps<br />

located in the <strong>di</strong>vertor port (fig. 2.6). Slots drilled in the<br />

<strong>di</strong>vertor body cassette provide for the needed pumping<br />

conductance. The plasma facing components are expected<br />

to be able to remove the heat load coming from the plasma<br />

via conduction and convection during the normal and<br />

transient operation. The outboard vertical target poloidal<br />

profile has been chosen in order to minimize the impinging<br />

heat loads by assuring ∼20° striking angle.<br />

Figure 2.5 – Complete CATIA5 model showing the<br />

main components of FAST: from outer to inner, the<br />

cryostat, the poloidal and toroidal field coils, the<br />

vessel with the access ports, the first wall with the<br />

<strong>di</strong>vertor and the central solenoid<br />

The hydraulic scheme of the <strong>di</strong>vertor cooling foresees a<br />

manifold which feeds the coolant into each tiles row from<br />

the top of the outer vertical target, the coolant than flows


fusion advanced stu<strong>di</strong>es torus (cont’d.)<br />

progress report<br />

2010<br />

051<br />

Pressure<br />

4.02×10 06<br />

3.77×10 06<br />

3.51×10 06<br />

3.25×10 06<br />

3.00×10 06<br />

2.74×10 06<br />

2.48×10 06<br />

2.23×10 06<br />

1.97×10 06<br />

1.72×10 06<br />

1.46×10 06<br />

Pa<br />

Figure 2.7 – Pressure in the <strong>di</strong>vertor pipes<br />

Figure 2.6 – FAST <strong>di</strong>vertor design with ~20° outward strike<br />

point angle<br />

along the dump plate and the dome, continues through<br />

the inner dump plate and vertical target and finally<br />

returns into the cassette manifold through the back of<br />

the inner vertical target. A preliminary 3D<br />

thermo–hydraulic analysis has been carried out for the<br />

<strong>di</strong>vertor module by using the ANSYS CFX fluid<br />

dynamics code. The total heat power on each in<strong>di</strong>vidual<br />

<strong>di</strong>vertor module a single module (the total power on the<br />

whole <strong>di</strong>vertor is 22.7 MW) has been splitted between<br />

the two vertical target surfaces (2/3 in the outer and 1/3<br />

in the inner vertical target) and applied as heat flow into<br />

the model. Assuming the water flowing with 10 Kgs –1<br />

rate and 4 Mpa pressure, 120°C as inlet con<strong>di</strong>tions, a<br />

2.2 MPa pressure drop (fig. 2.7) and 11°C temperature<br />

increase have been computed in a single <strong>di</strong>vertor<br />

module. The temperature <strong>di</strong>stribution along a single<br />

tiles row in the straight part of the outer vertical target<br />

has been evaluated by assuming the same inlet con<strong>di</strong>tion<br />

as before (1.67 Kg s –1 mass flow rate, 4 MPa inlet<br />

pressure, 120°C inlet temperature). The model includes<br />

the presence of the swirl tape as foreseen in the bottom<br />

part of the vertical target. It was supposed that the W<br />

monoblocks are bonded on the CuCrZr pipe by a Cu<br />

OFHC interlayer. The heat load has been assumed to<br />

vary exponentially with an energy decay length of 5 mm<br />

at the outer midplane and a factor 5 for the expansion<br />

at the target, thus resulting in ∼20 MWm –2 on the strike<br />

point. The average heat transfer coefficient at the<br />

interface between water and pipe has been computed as<br />

∼110 kW m –2 K –1 . The maximum stationary<br />

temperature reached is ∼1700°C on the W tile facing<br />

the plasma and ∼490°C on the Cu OFHC layer<br />

(fig. 2.8).<br />

Temperature<br />

1.7×10 03<br />

1.6×10 03<br />

1.4×10 03<br />

1.3×10 03<br />

1.1×10 03<br />

9.3×10 02<br />

7.7×10 02<br />

6.1×10 02<br />

4.4×10 02<br />

2.8×10 02<br />

1.2×10 02<br />

[C]<br />

Figure 2.8 – Temperature contour on the <strong>di</strong>vertor outer<br />

vertical target<br />

Figure 2.9 – FW and <strong>di</strong>vertor in the FAST CATIA5<br />

model<br />

First wall design<br />

The first wall design advanced in the last year, based<br />

upon a solution consisting in a bundle (fig. 2.9) of<br />

poloidal coaxial pipes (fig. 2.10) armoured with 4 mm<br />

thick plasma-sprayed W [2.10]. This configuration<br />

Figure 2.10 – Section of the FW model showing the<br />

poloidal coaxial pipes bundle


052<br />

progress report<br />

2010<br />

allows a very uniform temperature <strong>di</strong>stribution to be achieved by the pipes and gives the opportunity to have<br />

a single manifold for each segment, thus minimizing the eddy current effects on the structure and easing the<br />

system remote handling. The heat load impinging on the FW is, on average, 1 MW m –2 , with about<br />

3MWm –2 peak. The First Wall is designed to be actively cooled down by pressurized water flowing with a<br />

rate of 5 m s –1 , able to keep the temperature around 200°C in order to avoid any impurities adsorption. The<br />

design will be compatible with a completely remote handling and maintenance.<br />

Vacuum vessel design<br />

The vacuum vessel (VV) provides for vertical (up, down), oblique (up, down) and equatorial access ports (90 in<br />

total) for the plasma <strong>di</strong>agnostics, the vacuum, the auxiliary heating, the in–vessel remote handling (RH)<br />

maintenance and all of overall the systems that get to the vacuum vessel [2.10]. Special machine ports were<br />

designed to accommodate a 10 MW (45° inclined on the plasma cord) NNBI system (fig. 2.11) [2.13].<br />

The equatorial ports are characterized by an aperture shape that is relatively high and rather narrow. Two<br />

ports are one side enlarged to accommodate the NNBI beam. Since the beam are injected 45° on the magnetic<br />

axis the port available space is reduced. This configuration has been chosen to assure the best compromise<br />

between the narrow spaces and the designed 10 MW of power input to be supplied. Although at high density<br />

practically no shine–through is pre<strong>di</strong>cted, in case of low density operation a dump plate protection must be<br />

foreseen in the inner and outer first wall.<br />

Neutral beam<br />

Critical<br />

points<br />

NBI equatorial port<br />

Calorimeter<br />

Beam line vessel<br />

Figure 2.11 – Horizontal section of the NNBI system<br />

access port at FAST<br />

Figure 2.12 – FAST toroidal module<br />

The vacuum system has to reach a base pressure of<br />

about 1×10 –7 Pa, in order to minimise the presence of<br />

any possible residual impurities in the vacuum vessel<br />

before the plasma <strong>di</strong>scharge. By allowing for a specific<br />

outgassing rate (after all cleaning procedures) of<br />

6.7×10 –9 Pa m 3 s –1 m –2 , the needed effective pumping<br />

speed is about S eff<br />

=2.2 m 3 s –1 . The conductance<br />

between a pump and the vacuum vessel is dominated<br />

by the conductance of the vacuum line between the<br />

pump and the port, the <strong>di</strong>mensions of the latter being<br />

rather large. As a result the overall pumping speed<br />

must be about 4.25 m 3 s –1 and therefore 4<br />

turbomolecular pumps, with pumping speed of<br />

1.5 m 3 s –1 will have to be used.<br />

Toroidal field coil system<br />

The toroidal field coils (TFC) system has a 20°<br />

modular configuration (fig. 2.12), with a total of 18<br />

coils. Each coil consists of 14 oxygen free copper plates<br />

suitably worked to realize 3 turns in ra<strong>di</strong>al <strong>di</strong>rection.<br />

The turns of each coil are welded on the most external<br />

region in order to obtain a continuous helix and the<br />

plates are tapered at the innermost region to realise the<br />

wedged shape. A conceptual design of the fee<strong>di</strong>ng bars<br />

has been done, keeping in account the “return<br />

currents” for each coil: the relevant preliminary 3D<br />

electromagnetic analysis has not in<strong>di</strong>cated any<br />

noticeable perturbation introduced by the bars. In the<br />

highest performances H–mode scenario, a field of<br />

8.5 T is foreseen at the major ra<strong>di</strong>us R 0<br />

=1.82 m; this<br />

corresponds to a total of 76.5 MA–turn, i.e., to<br />

101.1 kA per turn. The maximum ra<strong>di</strong>al inward force<br />

acting on each TFC is 66.5 MN, while the vertical<br />

force on half of the TFC system is 690 MN, for the<br />

highest performance case. An appropriate structural


fusion advanced stu<strong>di</strong>es torus (cont’d.)<br />

progress report<br />

2010<br />

053<br />

analysis has been carried out, thus allowing to pre<strong>di</strong>ct a stress lower than 300 MPa for the worst case. The<br />

TFCs are kept together by a steel open structure surroun<strong>di</strong>ng them (fig. 2.13), a structure that should be quite<br />

elastic in order to be able to accommodate TFC thermal expansion with reasonable stresses. The same<br />

structure is also used to position the poloidal coils, which surround the TFC, and to fix the VV supports. Two<br />

preloaded rings, in the upper and lower zones of the structure, keep the whole TFC structure in wedged<br />

configuration.<br />

In order to increase the plasma duration in the NICD scenario, currently<br />

imposed by the TFC heating, and to address the DEMO con<strong>di</strong>tions, a<br />

feasibility study has been worked out to the purpose of analyzing the<br />

possibility of realizing FAST with a complete set of superconductor coils<br />

[2.14]. The toroidal field superconductor coil (TFSC) has been designed<br />

by filling up only the room available in the present copper conductors<br />

design. Due to the maximum magnetic field over the win<strong>di</strong>ng pack around<br />

14 T, in the innermost layer of the inboard straight leg on the equatorial<br />

plane for the reference H–mode scenario, the superconductor chosen is a<br />

Nb 3<br />

Sn cable–in–conduit–conductors (CICCs). The design envisages a<br />

Double–Pancake Win<strong>di</strong>ng Pack, wound from a rectangular conductor<br />

with an aspect ratio lower than 2, long twist pitch values, low void fraction<br />

and without any central channel. The nuclear heating for this option has<br />

been determined by using data provided by a MCNP code analysis [2.15].<br />

As the presence of a nuclear shield would considerably impact the<br />

machine geometry, it has been considered a solution not to envisage any<br />

neutron shield but with an actively He cooled steel casing, by means of adhoc<br />

designed channels. With this design, the conductor temperature<br />

margin is around 0.9 K for a nuclear heating of about 5 mW/cm 3 . Then<br />

superconductors coils could be introduced in the current machine load<br />

assembly design without any major mo<strong>di</strong>fications [2.16].<br />

Figure 2.13 – Model of the TFC<br />

supporting structure<br />

Toroidal field ripple reduction<br />

The plasma boundary in FAST is close to the TFCs, thus resulting in a<br />

relatively high (as in ITER) deviation from the toroidal symmetry of the<br />

toroidal magnetic field, known as toroidal field ripple (TFR). The TFR<br />

maximum value in FAST is, without any correcting solution, about 1.5%<br />

on the plasma separatrix region at 45% from the equatorial plane. The<br />

first solution, analysed to the purpose of reducing the TFR as much as<br />

possible, was based on the insertion of ferrite elements between the TFCs<br />

and the plasma. Nevertheless, this solution could produce the appearance<br />

of a TFR with opposite sign when operating at lower toroidal field, as it<br />

is widely foreseen in FAST. A conceptual study was then performed to<br />

analyze the option of realizing an active control of the ripple amplitude<br />

[2.16] by means of proper coils located outside the VV in front of every<br />

TFC (fig. 2.14) and fed with a current in the opposite <strong>di</strong>rection as to the<br />

Figure 2.14 – Schematic view of the<br />

active coils designed to control the<br />

ripple amplitude<br />

TFC current. The maximum current foreseen for these coils is the same as for the TFC system, thus<br />

simplifying then the power supply and fee<strong>di</strong>ng issues. By varying the current in coils the ripple value can be<br />

actively controlled up to reverse its sign, thus allowing not only the required reduction to values compatible<br />

with plasma operations but also the flexibility needed to study the ripple role in the pedestal behaviour and in<br />

the H–mode performance. Preliminary structural stu<strong>di</strong>es in<strong>di</strong>cated that the forces exerted on these coils<br />

require the design of proper support structures to be integrated in the vacuum vessel.<br />

Poloidal field coil system<br />

The poloidal field (PF) coils system, consisting of a vertically segmented (in 6 modules) central solenoid (CS)<br />

and of 6 external coils, allows for the needed poloidal flux swing requested to create and maintain the plasma<br />

as well as and for shaping flexibility. In the present design the CS, the external PFCs and the busbars are made<br />

of hollow copper conductors for cooling.


054<br />

progress report<br />

2010<br />

Although the PFC system is not the main element constraining the plasma duration, a feasibility study has<br />

been performed to analyze the opportunity to realize it with superconductors [2.14]. The large flux necessary<br />

for the plasma sustainment brings to maximum magnetic fields around 17.7 T in the CS, on the equatorial<br />

plane, which represents a <strong>di</strong>fficult challenge for the superconductor coils design. In order to investigate its<br />

feasibility, a design of the 6 CS modules by using Nb 3<br />

Sn strand, characterized by high critical current density<br />

performance, has been carried out while maintaining at the same time such stringent operative con<strong>di</strong>tions and<br />

taking up the same room foreseen for the copper in the reference design. The high value of the maximum<br />

magnetic field in the CS conductor will require future mo<strong>di</strong>fications of the coil design to be performed, mainly<br />

by introducing conductor gra<strong>di</strong>ng aimed at optimizing the room occupancy and thus the current density level.<br />

Moreover the large magnetic field variation during the scenario, in the order of 1÷2 T/s, will require a careful<br />

AC losses analysis to analyze their impact on the strand choice.<br />

As for the 6 external PFCs superconductor option, the relatively low maximum magnetic field suggested the<br />

use of NbTi CICCs, which is affected by degradation of performance due to the EM loads lower than the<br />

Nb 3<br />

Sn strands. Also these external coils were designed with a rectangular shape to permit a higher packing<br />

factor without degra<strong>di</strong>ng the single strand performance.<br />

Poloidal field coil system flexibility and plasma control<br />

FAST has been designed to allow a large flexibility in the plasma shape to be achieved: to investigate and<br />

optimize this feature of the machine, the extreme shape control (XSC) algorithm, developed for Joint<br />

European Torus (JET) [2.18], has been also applied to FAST [2.19]. The XSC Tools implementation for<br />

FAST has shown the possibility to achieve plasma shapes significantly <strong>di</strong>fferent from the reference ITER–like<br />

shape, for instance with an increased aspect ratio R/a up to 4. Another application enabled by XSC Tools is<br />

the possible sweeping of the plasma boundary strike points on the <strong>di</strong>vertor plates, with a fixed plasma shape,<br />

to spread out the energy deposition on the plates. A strike point movement around 12 cm, on the vertical<br />

target, has been shown to be possible by leaving unchanged the reference plasma boundary unchanged.<br />

Cooling system<br />

Helium gas is used for cooling the magnets down to 30 K. The refrigerator is required to operate in a steady<br />

state cooling mode. However the heat load of the magnet system is delivered in pulses and then the smoothing<br />

of the pulsed heat load will be taken into account for the refrigerator design by inclu<strong>di</strong>ng details of buffer tank<br />

and heat transfer in the magnet system. The inner surface of the cryostat and the VV are covered with 80 K<br />

thermal shield to prevent high heat ra<strong>di</strong>ation from the cryostat to the machine and from the VV to the toroidal<br />

field coils. The total heat load required to maintain the machine at 30 K temperature has been assessed as 5<br />

kW. For the most deman<strong>di</strong>ng scenario (pulse length up to 170 s) the inter–pulse cooling time is below 1 h. The<br />

refrigerator concept makes reference to the detailed study carried out by Linde Kryotechnik AG for a similar<br />

plant.<br />

Remote handling<br />

Due to neutron activation [2.15], the repair, inspection and maintenance of FAST in–vessel components<br />

should be performed remotely. The scheme of the <strong>di</strong>vertor maintenance operation is foreseen as in ITER, with<br />

the frame acting as a carousel around the machine to move the <strong>di</strong>vertor modules by mean of an ad-hoc<br />

developed cassette tractor, capable to grasp, pull and push the cassettes through the oblique lower port.<br />

Collaborations with the ITER Divertor Test Platform in Tampere (Finland) and with the Department of<br />

Mechanics, Virtual Reality Laboratory, of the Napoli II University have been started for this purpose and a<br />

first simulation of the <strong>di</strong>vertor modules movement has been performed by using the FAST full model. As for<br />

the first wall remote assembly and <strong>di</strong>sassembly, a classical articulated boom plus a front end manipulator has<br />

been considered.


fusion advanced stu<strong>di</strong>es torus (cont’d.)<br />

progress report<br />

2010<br />

055<br />

References<br />

[2.1] N. Hosogane et al., Fusion Sci. Tech. 52, 375 (2007)<br />

[2.2] A. Pizzuto et al. , Nucl. Fusion 50, 095005 (2010)<br />

[2.3] B.B. Kadomtsev, Sov. J. Plasma Phys. 1, 295(1975)<br />

[2.4] X. Wang, et al., An extended hybrid magnetohydrodynamics gyrokinetic model for numerical simulation of<br />

shear Alfvén waves in burning plasmas, accepted for publication in Phys. Plasmas<br />

[2.5] L. Chen and F. Zonca, Nucl. Fusion 47, S727 (2007)<br />

[2.6] F. Zonca et al., Plasma Phys. Control. Fusion 48, B15 (2006)<br />

[2.7] V. Pericoli–Ridolfini et al., Simulations of the SOL plasma for FAST, a proposed ITER satellite tokamak, Presented<br />

at the 26th Symposium on Fusion Technology – SOFT (Porto, 2010) and to appear in Fusion Eng. Des.<br />

[2.8] M. Tardocchi et al., Production and <strong>di</strong>agnosis of energetic particles in FAST, Procee<strong>di</strong>ngs of the 23rd IAEA<br />

Fusion Energy Conference (Daejon 2010), CN–180 – Paper EXW/P7–26 (2010)<br />

[2.9] F. Crisanti et al., FAST: a European ITER satellite experiment in the view of DEMO, Presented at the 26th<br />

Symposium on Fusion Technology – SOFT (Porto, 2010) and to appear in Fusion Eng. Des.<br />

[2.10] A. Cucchiaro et al., Engineering evolution of the FAST machine, Presented at the 26th Symposium on Fusion<br />

Technology – SOFT (Porto, 2010) and to appear in Fusion Eng. Des.<br />

[2.11] E. Visca et al., Manufacturing, testing and post–test examination of ITER <strong>di</strong>vertor vertical target W small scale<br />

mock–ups, Presented at the 26th Symposium on Fusion Technology – SOFT (Porto, 2010) and to appear in<br />

Fusion Eng. Des.<br />

[2.12] S. Roccella et al., Non–destructive methods for the defect detection during the manufacturing of ITER high<br />

heat flux components, Presented at the 26th Symposium on Fusion Technology – SOFT (Porto, 2010) and to<br />

appear in Fusion Eng. Des.<br />

[2.13] M. Baruzzo et al., Requirements specifications for the neutral beam injector on FAST, Presented at the 26th<br />

Symposium on Fusion Technology – SOFT (Porto, 2010) and to appear in Fusion Eng. Des.<br />

[2.14] A. Di Zenobio et al., FAST: Conceptual design for a completely superconducting magnet system, to appear in<br />

IEEE Trans. Appl. Supercond.<br />

[2.15] R. Villari et al., IEEE Trans. Plasma Sci. 38, 406-413 (2010)<br />

[2.16] G.M. Polli et al., A 2D thermal analysis of the superconducting proposal for the TF magnet system of FAST,<br />

Presented at the 26th Symposium on Fusion Technology – SOFT (Porto, 2010) and to appear in Fusion Eng.<br />

Des.<br />

[2.17] G. Calabrò et al., Active toroidal field ripple reduction on FAST, Presented at the 26th Symposium on Fusion<br />

Technology – SOFT (Porto, 2010) and to appear in Fusion Eng. Des.<br />

[2.18] R. Albanese et al., Fusion Eng. Des. 74, (2005).<br />

[2.19] F. Maviglia et al., Poloidal field circuits sensitivity stu<strong>di</strong>es and shape control in FAST, Presented at the 26th<br />

Symposium on Fusion Technology – SOFT (Porto, 2010) and to appear in Fusion Eng. Des.


056<br />

progress report<br />

2010<br />

chapter 3<br />

technologyprogramme<br />

The technology program performed by the Association in 2010 cover the most crucial activities related to<br />

ITER, the European Fusion Development Agreement (EFDA) program and Broader Approach (BA)<br />

agreement.<br />

Many of these activities were performed within Consortia established among Association and collaboration<br />

with industry.<br />

The most relevant results achieved in the period are the following.<br />

The <strong>ENEA</strong> technology developed for the construction of the <strong>di</strong>vertor monoblock plasma facing units has been<br />

successfully applied, in collaboration with Ansaldo Nucleare, for the construction of the qualification<br />

prototype.<br />

An important irra<strong>di</strong>ation experiment has been carried out to assess the design of the ITER shiel<strong>di</strong>ng blanket.<br />

A mock up of the shiel<strong>di</strong>ng blanket plus vacuum vessel and the toroidal field (TF) magnet (utilizing actual<br />

cable–in–conduit (CIC) conductor) has been irra<strong>di</strong>ated. The test results were very useful to reduce the<br />

uncertainties on the heat deposited on the superconductors and to better define the shield block design. A<br />

number of MCNP models have been developed in the frame of the design of the high resolution spectrometer,<br />

the ra<strong>di</strong>al neutron camera and the in vessel and <strong>di</strong>vertor coils. Concerning sensor development, further to the<br />

continuation of the <strong>di</strong>amond sensors, gas electron multiplier (GEM) were utilised as neutron detectors.<br />

The in vessel viewing system (IVVS) developed by <strong>ENEA</strong> for ITER has been further improved by ad<strong>di</strong>ng a<br />

vibration filtering system.<br />

Safety stu<strong>di</strong>es have been performed for studying the mobilization of dusts in the event of a loss of vacuum<br />

accident. Experimental and modelling activities were accomplished with also with the aim to develop the<br />

proper <strong>di</strong>agnostic system.<br />

In the field of materials, a multi-scale method for modelling ceramic composites has been implemented<br />

developing a special subroutine to be utilised in ABAQUS code.<br />

In Brasimone the breeder blanket test facilities were further improved with the commissioning of TRItium<br />

EXtraction (TRIEX) loop for the simulation of the lithium lead purification system.<br />

The Broader Approach activities were mainly focussed on the International Fusion Materials Irra<strong>di</strong>ation<br />

Facility (IFMIF) and materials. Target design based on an alternative remote handling scheme has been further<br />

developed and the preparation of the experimental activity in EVEDA lithium test experiment (ELITE) facility<br />

in Japan has been started. Test facility to investigate the compatibility issues of SiC/SiC in high temperature<br />

flowing lithium has been realised. In this frame the construction of lithium purification loop has been<br />

completed. As for the Japan Tokamak 60 Super Advanced (JT60–SA), the technical specification of the TF<br />

magnet have been finalised and those for the power supply and switching system are in progress.<br />

Training activities have been performed in the field of liquid metal, magnet and <strong>di</strong>vertor technology in the<br />

frame of the Euratom training scheme.


technology programme (cont’d.)<br />

progress report<br />

2010<br />

057<br />

3.1 Divertor, First Wall, Vacuum Vessel and Shield<br />

Manufacturing technology for the ITER inner vertical target<br />

<strong>ENEA</strong> has been deeply involved in the ITER R&D activities for the manufacturing of high heat flux<br />

plasma–facing components, and in particular for the inner vertical target (IVT) of the ITER <strong>di</strong>vertor.<br />

This component has to be manufactured by using both armour and structural materials whose properties are<br />

defined by ITER. Their physical properties prevent standard joining techniques from being applied. The<br />

reference armour materials are tungsten and carbon/carbon fibre composite (CFC), and, for the cooling pipe,<br />

a copper alloy (CuCrZr).<br />

During the last years <strong>ENEA</strong>, in collaboration with Ansaldo, has been manufacturing several actively cooled<br />

mock–ups and prototypical components of <strong>di</strong>fferent length, geometry and materials, by using innovative<br />

processes: hot ra<strong>di</strong>al pressing (HRP) and pre–brazed casting (PBC).<br />

The optimization of the processes started from the successful manufacturing of both W and CFC small scale<br />

mockups and successful testing in the worst ITER operating con<strong>di</strong>tion (20 MW/m 2 ) through the achievement<br />

of record performances obtained from a me<strong>di</strong>um scale IVT CFC and W armoured mockup: after ITER<br />

relevant heat flux fatigue testing (20 MW/m 2 for 2000 cycles CFC part, 15 MW/m 2 for 2000 cycles W part)<br />

it reached a critical heat flux of 35 MW/m 2 at ITER relevant thermal–hydraulic con<strong>di</strong>tions.<br />

On the basis of these results, <strong>ENEA</strong>–ANSALDO participated in the European program for the qualification<br />

and manufacturing of the <strong>di</strong>vertor IVT, accor<strong>di</strong>ng to the Fusion For Energy (F4E) specifications. A <strong>di</strong>vertor<br />

IVT prototype (400 mm total length) with three plasma facing component units (fig 3.1) was successfully tested<br />

at ITER relevant thermal heat fluxes (20 MW/m 2 for 3000 cycles CFC part, 15 MW/m 2 for 3000 cycles W<br />

part).<br />

Now, this technology is ready to face the challenge of the ITER<br />

IVT production, thus transferring the experience gained in the<br />

development, optimization and qualification of the PBC and<br />

HRP processes to an industrial production line.<br />

Qualification of ultrasonic non–destructrive testing method<br />

for plasma facing components<br />

Under the “EURATOM Training Network for Plasma–facing<br />

Materials” (ETN_PFM) (Contract No. 042314 (FU 06)), <strong>ENEA</strong><br />

was assigned with a trainee to be prepared in the area of<br />

“Design, manufacturing and acceptance procedures of PFC”.<br />

This area is strictly linked to the activities related to the<br />

Figure 3.1 – ITER <strong>di</strong>vertor IVT qualification<br />

prototype manufactured by <strong>ENEA</strong>–Ansaldo


058<br />

progress report<br />

2010<br />

development and manufacturing of plasma facing compontens<br />

(PFCs) for the ITER tokamak and to the qualification of the<br />

manufacturing technologies for the ITER <strong>di</strong>vertor procurement.<br />

Figure 3.2 – Plane CFC–Cu joint sample<br />

Amplitude<br />

40<br />

30<br />

20<br />

10<br />

0 0 0 20<br />

C-scan 0<br />

C-scan 1<br />

C-scan<br />

REPORT<br />

100<br />

0<br />

-100<br />

Nome del file<br />

30 40 50 60<br />

13.39 17.39 22.00<br />

-19.28 43.75 0.00<br />

120<br />

80<br />

40<br />

0<br />

DX mm<br />

32.67<br />

DY mm<br />

26.36<br />

TXT<br />

OK<br />

D:\Lavoro\ULTRASUONI\CAMPIONE01ULTRAN\ultime provecd<br />

plane15.rf1<br />

One of the main issues in the manufacturing of the plasma facing<br />

units is the reliability of the non destructive controls that are<br />

necessarily performed during the manufacturing process. <strong>ENEA</strong> has<br />

developed a suitable ultrasonic technique (UT) for the control of all<br />

the joining interfaces of the ITER <strong>di</strong>vertor IVT plasma facing units,<br />

but the defect detection capability of the method has to be proved for<br />

both metal to metal and metal to CFC joints, since both types of<br />

joints are present. Within this activity, the UT results coming from<br />

the investigation being performed during the manufacturing, but also<br />

after the thermal fatigue testing (up to 20 MW/m 2 ) of mock–ups<br />

manufactured in <strong>ENEA</strong> labs by using the HRP technology were<br />

stu<strong>di</strong>ed and compared with the evidences coming from the final<br />

destructive examination in order to qualify the method. Regar<strong>di</strong>ng<br />

the Cu/CFC joint, the effectiveness of the ultrasonic test has been<br />

deeply stu<strong>di</strong>ed due to the high acoustic attenuation of CFC to<br />

ultrasonic waves. For these purpose an ‘ad hoc’ plane Cu/CFC joint<br />

sample, that reproduces the actual annular joint interfaces, was<br />

manufactured. This plane sample has the advantage of being easily<br />

tested by probes with <strong>di</strong>fferent geometry and ultrasonic<br />

characteristics. UT testing results were compared with x–ray and<br />

Eddy current of the same sample.<br />

The results confirmed that the evidences detected by UT can be<br />

easily correlated to lack of adhesion of the copper to CFC; in fact,<br />

the position of the defective zones coincides with the points where<br />

the brazing alloy deposition <strong>di</strong>d not succeed.<br />

Figure 3.2 shows the CFC–Cu sample being used for the testing and<br />

figure 3.3 compares the images obtained by the <strong>di</strong>fferent techniques:<br />

UT, x–ray, Eddy current.<br />

C-scan<br />

Height<br />

0<br />

10<br />

20<br />

30<br />

0 50 100 150<br />

Figure 3.3 – Images obtained by UT,<br />

x–ray, and Eddy current<br />

Analysis of the ITER <strong>di</strong>vertor cassettes<br />

<strong>ENEA</strong> completed the activities related to the performing of a new set<br />

of 3D electromagnetic (EM) and mechanical analyses of the revised<br />

design of the ITER <strong>di</strong>vertor cassettes to the purpose of checking the<br />

fulfillment of the requirements and better assessing the merits of<br />

each envisaged alternative during several off–normal events,<br />

inclu<strong>di</strong>ng category II and III events. These activities, in the frame of<br />

the European Fusion Development Agreement (EFDA) Contract 07–<br />

1702/1596 (TW6–TVD–DIAGAN) [3.1], were performed with the<br />

support of L.T. Calcoli, an Italian company specialized in<br />

electromagnetic and structural finite element analysis.<br />

The Divertor is one of the most challenging components of the ITER machine: it is designed to sustain the<br />

heat load and reduce the impurity in the plasma: it consists of the PFCs and a massive structure called the<br />

cassette body (CB) (fig. 3.4). The PFCs are actively cooled thermal shields required to sustain the heat and<br />

particle fluxes during normal and transient operations as well as during <strong>di</strong>sruption events. The CB is needed<br />

for supporting the PFCs, routing the water coolant into them and provi<strong>di</strong>ng neutron shiel<strong>di</strong>ng: it is mounted<br />

onto the vacuum vessel’s (VV) inboard and outboard rails via a mechanical locking system.<br />

The performed 3D EM numerical analysis allowed the EM loads to be calculated, inclu<strong>di</strong>ng integral forces<br />

and moments on the PFCs, CBs and components (pipes, manifolds and multilinks in figure 3.5) due to halo<br />

and Eddy currents by taking into account both the thermal and current quench. The EM loads thus obtained<br />

were then transferred for the correspon<strong>di</strong>ng dynamic mechanical analysis that allowed the stresses and


technology programme (cont’d.)<br />

progress report<br />

2010<br />

059<br />

Inner vertical target<br />

Outer vertical target<br />

Dome<br />

Figure 3.4 – ITER <strong>di</strong>vertor<br />

location and components<br />

Cassette body<br />

Figure 3.5 – Multilinks between<br />

the CB and the PFCs<br />

Figure 3.6 – Halo<br />

current <strong>di</strong>stribution<br />

for the central halo<br />

current path<br />

73.387 0.216×10 07 0.432×10 07 0.648×10 07 0.864×10 07<br />

0.108×10 07 0.324×10 07 0.540×10 07 0.756×10 07 0.972×10 07<br />

<strong>di</strong>splacements generated in the <strong>di</strong>vertor structural parts to be<br />

calculated and the stresses generated during off–normal events with<br />

the ITER structural design criteria to be compared.<br />

Several EM finite element models (FEMs) were developed to<br />

analyze the effects due to the poloidal halo currents (fig. 3.6) and<br />

the poloidal and toroidal field variation during both fast and slow<br />

plasma vertical <strong>di</strong>splacement events (VDE) which lead to category<br />

II and III plasma <strong>di</strong>sruptions. The Slow Downward VDE–III with<br />

inward halo currents configuration has been selected, on the basis<br />

of the resultant EM loads, as the worst con<strong>di</strong>tion to be used for the<br />

next structural assessment. Both the standard cassette in front to the<br />

cryo–pump port (fig. 3.7) and that between ports were modeled also<br />

by taking in account the possible bridging on the plasma–facing<br />

units (PFUs). These analyses showed that no significant <strong>di</strong>fference<br />

on the EM loads is produced by the port hole and that the bridged<br />

configurations generate loads higher than the unbridged ones on<br />

the CB.<br />

Figure 3.7 – FEM of the standard cassette<br />

in front of the cryo–pump port<br />

The structural assessment required for the development of a more detailed FEM (fig. 3.8) in order to<br />

perform proper static and dynamic analyses under the selected load con<strong>di</strong>tions, obtained by combining the<br />

EM forces with the ad<strong>di</strong>tional loads due to dead weight, hydraulic pressure, initial preload of the CB and<br />

thermal stress from normal operating con<strong>di</strong>tions.<br />

The elastic and elasto–plastic mechanical analyses allowed stresses, reaction forces, moments and<br />

<strong>di</strong>splacements produced in the <strong>di</strong>vertor structural parts and attachments to be calculated, both for the<br />

original and the updated geometry, with and without bridging of the PFUs. The structural integrity of the<br />

<strong>di</strong>vertor components and the compliance with the ITER structural design criteria was then assessed for the<br />

updated Dome geometry both for category II and III loads.


060<br />

progress report<br />

2010<br />

Figure 3.8 – Details of the structural FEM of the <strong>di</strong>vertor system: CB with locking<br />

system, dome and VT<br />

3.2 Breeder Blanket and Fuel Cycle<br />

European Bree<strong>di</strong>ng Blanket Test Facility design and construction<br />

The European Bree<strong>di</strong>ng Blanket Test Facility (EBBTF) is the reference European facility for the qualification<br />

of test blanket modules (TBMs). It is constituted by the Integrated European Lead Lithium LOop (IELLLO)<br />

and the HElio for FUSion loop (HEFUS 3).<br />

In 2009 the lead lithium to fill the loop and complete the commissioning was received in <strong>ENEA</strong> Brasimone.<br />

The acceptance procedure took a long time due to large <strong>di</strong>fferences in the lithium content, and the procedure<br />

was concluded in November. The loop was filled in February 2010. The new HEFUS 3 circulator was<br />

delivered in <strong>ENEA</strong> Brasimone in the first weeks of 2010 and the installation completed in the first semester<br />

of 2010.<br />

TRIEX loop for studying technologies of tritium extraction from<br />

Pb–17Li<br />

The main objective to be achieved in the TRItium EXtraction (TRIEX)<br />

facility is to verify the efficiency of the hydrogen extraction system from<br />

the liquid metal loop in the range of operating con<strong>di</strong>tions of the European<br />

TBM (fig. 3.9).<br />

In order to carry out the tests, in 2010 the mechanical pump was requalified<br />

and inserted into the TRIEX loop. In April the pump was not<br />

characterized in lead lithium due to the mechanical pump failure after 12h<br />

of work. On the basis of this experience, an upgra<strong>di</strong>ng of the TRIEX loop<br />

was planned and a new pump was selected. The new loop is expected to<br />

start in November 2011.<br />

Figure 3.9 – TRIEX loop<br />

Electromagnetic load analysis for the design of the blanket manifold pipe<br />

concept for ITER<br />

<strong>ENEA</strong> completed the activities related to the 3D EM load analysis of the new manifold concept (NMC) for<br />

the ITER blanket and shield system, accor<strong>di</strong>ng to the EFDA Contract 07–1702/1620 (TW6–TVB–MANEM)<br />

[3.2]. The activities were performed with the support of L.T. Calcoli company.


technology programme (cont’d.)<br />

progress report<br />

2010<br />

061<br />

The ITER blanket and shield system is the<br />

innermost part of the reactor; it is <strong>di</strong>rectly<br />

exposed to the plasma and provides the main<br />

thermal and nuclear shiel<strong>di</strong>ng to the vacuum<br />

vessel and external reactor components. Its<br />

concept is based on a modular configuration with<br />

blanket modules consisting of water–cooled<br />

austenitic stainless steel shield blocks and<br />

separable first–wall (FW) panels, mechanically<br />

attached to the shield blocks. The blanket<br />

modules have typical <strong>di</strong>mensions of<br />

1m× 1.5 m × 0.5 m and are mechanically<br />

attached to the VV. The water coolant is supplied<br />

to the modules by a set of inlet and outlet<br />

manifolds attached to the inner wall of the VV.<br />

Figure 3.10 – Proposed design and detail of the FEM of the<br />

inboard ITER shiel<strong>di</strong>ng blanket NMC inclu<strong>di</strong>ng the inner vessel<br />

shell, the modules #6 and #7 and part of the single pipe<br />

assembly<br />

This work was performed to evaluate the eddy currents and the forces induced by fast variations of the<br />

magnetic fields due to plasma off–normal events in the NMC where the original welded structure supplying<br />

the cooling water to each module has been replaced by single pipes. This evaluation was needed to address<br />

some concerns raised during the ITER design review about the capability of repairing the components<br />

remotely and the high operating stresses and possible water leakages that might be produced at some locations<br />

on the manifolds.<br />

The FEMs developed for these analyses (fig. 3.10) include a 10° toroidal sector of the ITER machine with the<br />

double shell vessel, the <strong>di</strong>vertor, the blanket modules and a quite detailed model of the pipe manifold where<br />

each pipe is insulated from the other pipes, the blanket and the vessel except in the points where the pipes are<br />

bundled together and attached to the vessel.<br />

The 3D EM load analyses, performed by using the ANSYS code, allowed the time evolution of the current<br />

and ben<strong>di</strong>ng force to be evaluated per unit length in the whole bundle as well as the current sharing between<br />

the whole pipe bundle and the vessel, for several plasma off–normal events. The major <strong>di</strong>sruption type II with<br />

36 ms linear current quench was proved to be the most severe event as far as the force per unit length on a<br />

single pipe, even if the total force on the manifold is larger during the thermal quench, because the eddy<br />

current is not shared among the pipes but is concentrated in the first part of a single pipe at each manifold<br />

section. The EM loads induced on the NMC are lower as compared to the reference concept, but this<br />

advantage has to be confirmed in terms of mechanical stresses due to the significant <strong>di</strong>fferences among the<br />

mechanical structures. In any case, the large resulting EM loads must be carefully considered in the detailed<br />

design of the manifold components and their supporting systems.<br />

Development of method for highly tritiated water handling in ITER tritium plant<br />

A process based on a combination of permeator catalyst (PERMCAT) (Pd–based membrane reactor) and<br />

vapor phase catalytic exchange (VPCE) has been stu<strong>di</strong>ed for processing higly tritiated water (HTW) (ITER<br />

contract ITER–CT–09–4300000087). The simulation of the PERMCAT and VPCE systems has been carried<br />

out and the process flow <strong>di</strong>agram has been prepared [3.3]. As a main advantage, the process being proposed<br />

permits to combine the PERMCAT and VPCE in several ways accor<strong>di</strong>ngly to the characteristics of the<br />

<strong>di</strong>fferent HTW streams to be processed. Furthermore, both PERMCAT and VPCE can use the mixture of<br />

hydrogen isotopes produced by the electrolyzers of the water detritiation system as sweep gas, thus reducing<br />

the impact on the isotopic separation system and avoi<strong>di</strong>ng the generation of secondary wastes.<br />

Training activities<br />

<strong>ENEA</strong> Frascati laboratories have had in charge a Trainee (EURATOM Research Training Network<br />

"Preparing the ITER Fuel Cycle" – Contract No. 042862 (FU 06)) to be prepared in the area of the fuel cycle<br />

of ITER. All the activities have been completed by achieving the milestones of the task: study of cold–rolling<br />

and <strong>di</strong>ffusion wel<strong>di</strong>ng techniques, long–term testing of Pd/Ag membranes, participation to the CAPER R&D<br />

program, tritium confinement study [3.4], analysis of tritium release from the neutral beam injector [3.5] and<br />

inactive tests for new PERMCAT prototypes [3.6].


062<br />

progress report<br />

2010<br />

<strong>ENEA</strong> Frascati laboratories have also had in charge an Early Stage Researcher (EFDA Goal Oriented Training<br />

Programme “Tritium Technologies for the Fusion Fuel Cycle” – TRI–TOFFY) to be prepared in the<br />

deuterium–tritium fuel cycle area for ITER. Main research activities have consisted in characterizing thin wall<br />

Pd–based permeator tubes in terms of hydrogen permeability and selectivity and the hazard and operability<br />

study (HAZOP) for the HTW process system of ITER. For the treatment of HTW three processes have been<br />

stu<strong>di</strong>ed in details [3.7]: water decomposition by using the water gas shift reaction, high temperature electrolysis<br />

and water splitting through reduction on metals. Particularly, the use of Pd–based membrane reactor for<br />

carrying out the water gas shift reaction of tritiated water permits high reaction yields to be reached and pure<br />

hydrogen isotopes to be recovered, which can be <strong>di</strong>rectly sent to the isotopic separation system.<br />

3.3 Magnet and Power Supply<br />

Optimization of the toroidal field ripple reduction system<br />

The ITER toroidal field coil (TFC) system is made of 18 D–shaped coils spaced by 20° in toroidal angle. The<br />

<strong>di</strong>scontinuity produces a deviation (ripple) from the toroidal <strong>di</strong>rection of the magnetic flux surfaces that can<br />

cause significant losses in the confinement of high energy particles (α–particles or high–energy ions from<br />

neutral beam injectors) due to their trapping inside the “ripple valleys” and unwanted peaking in the heat loads<br />

on the FW. Due to these reasons, an accurate evaluation of the toroidal field ripple (TFR) was performed in<br />

various operation con<strong>di</strong>tions. This evaluation was carried out by means of finite element models built only by<br />

using structured meshes in order to obtain a very high field precision on a regular spaced grid extended to the<br />

entire region enclosed in the FW. The model was built by taking into account the real 3–D shape of the TFC<br />

and modelling three nested D shaped coils capable of carefully reproducing the real geometry of the TFC.<br />

The analysis showed a high value of TFR (excee<strong>di</strong>ng 1% in the outboard plasma region near the equatorial<br />

plane) and this confirmed the need for introducing some correcting elements. The implementation of<br />

ferromagnetic SS430 steel inserts in the outboard region between the inner and outer vessel shells, properly<br />

optimized in shape, size and location, then allowed the maximum ripple at the plasma separatrix to be reduced<br />

to 0.19% (fig. 3.11); this value could increase up to 0.38% when the number of inserts was limited by the filling<br />

factor required for ITER design.<br />

The analysis also confirmed that the introduction of ferromagnetic inserts into the equatorial region between<br />

equatorial ports is essential to reduce the TFR to acceptable levels in the plasma region. The optimization of<br />

the ferromagnetic inserts was performed by taking care of limiting the ripple over–compensation under 0.6%<br />

during plasma operation at half toroidal field.<br />

0.268×10 -3 0.736×10 -3 0.001205 0.001674 0.002142<br />

0.502×10 -3 0.001908<br />

SMN=0.357×10 -5<br />

0.971×10 -3 0.001439<br />

Optimized insert plate<br />

SMX=0.010749<br />

<strong>di</strong>stributions each plate is 4.4 cm<br />

thick with a filling factor of 4.4<br />

0.357×10 -5<br />

0.001198<br />

Ripple in the plasma<br />

region with optimized<br />

insert <strong>di</strong>stribution around<br />

ports without NBI<br />

Enlarged<br />

scale<br />

0.002392 0.004779 0.007167 0.009555<br />

0.003585 0.005973 0.008361<br />

Maximum ripple<br />

at the separatrix<br />

0.188%<br />

Figure 3.11 – ITER ripple map at full toroidal field with the optimized <strong>di</strong>stribution of<br />

the inserts<br />

Equatorial port position<br />

Three–<strong>di</strong>mensional<br />

magneto–static analyses<br />

for ITER<br />

<strong>ENEA</strong> completed the<br />

activities related to several<br />

magneto–static analyses<br />

in ITER accor<strong>di</strong>ng to the<br />

EFDA Study Contract<br />

07–1702/1602<br />

(TW6–TPO–3DMAGS):<br />

the optimization of the<br />

shape, size and location of<br />

the ferromagnetic plates<br />

used for the reduction of<br />

the TFR; the evaluation<br />

of the Maxwell’s forces on<br />

these plates and the<br />

analysis of the effects on<br />

the ripple due to the<br />

ferromagnetic materials<br />

in the magnetic shields of


technology programme (cont’d.)<br />

progress report<br />

2010<br />

063<br />

the neutral beam injection (NBI) and the TBMs; the optimization of the NBI magnetic field reduction system<br />

in reducing the residual field to the requested level for operation; the evaluation of the effects of ferromagnetic<br />

material present in the buil<strong>di</strong>ng concrete surroun<strong>di</strong>ng the torus on the stray field in the NBIs system, over the<br />

plasma region and outside the bio–shield structure. These analyses were performed with the support of L.T.<br />

Calcoli by developing in ANSYS several 3D magneto–static FEMs by using a parametric approach which<br />

allows an easy change of the models geometric main features to match <strong>di</strong>fferent design options.<br />

Analysis of the ripple effects due to the ferromagnetic materials in the NBI magnetic shields and the test<br />

blanket modules<br />

Some ferromagnetic components foreseen in the ITER design are not uniformly spaced along the toroidal<br />

angle and can then dramatically increase the ripple in the region where they are placed. To evaluate this<br />

increase, two TBMs were modelled as blocks of EUROFER ferromagnetic material (2700 kg each one) and<br />

placed in two ITER equatorial ports: their complete saturation, at about 1.9 T during ITER operation,<br />

induced a toroidal field perturbation at the plasma separatrix up to 1.0%. Moreover, the equatorial ports<br />

devoted to NBIs cannot allocate the same ferromagnetic inserts shape foreseen for standard ports, due to their<br />

<strong>di</strong>fferent geometry: properly optimized in shape and thickness inserts are required around these ports and<br />

induce a further perturbation of the toroidal ripple map.<br />

Detailed TFR maps of the plasma region were produced (fig. 3.12) by considering the real geometry at the<br />

operating temperature, with a relative precision in the error field better than 1%.<br />

Assessment of the NBI magnetic field reduction system<br />

The residual magnetic field inside the NBI region is required to be very low in order to avoid the deflection of<br />

the ion beam before neutralization, and to achieve the requested performances. In ITER, both passive and<br />

active shiel<strong>di</strong>ng systems are foreseen to the purpose of reducing by several order of magnitude the stray field<br />

inside the NBI region due to the plasma, the currents in the magnetic field coils and all the magnetized<br />

components around it.<br />

A detailed FEM of the whole NBI system was developed (fig. 3.13) by using a fully parametric approach to<br />

allow an easy change of the iron shiel<strong>di</strong>ng thickness (15 cm at the present), coil shapes and NBI shiel<strong>di</strong>ng box<br />

geometry during the optimization. The effects on the stray field of the ferromagnetic materials in the buil<strong>di</strong>ng<br />

were roughly reproduced in the model by adequately rearranging the currents in the PF coils and the plasma.<br />

TBM<br />

region<br />

TBM+new optimezed Fe<br />

inserts isosurfaces of dBtor<br />

40° sector of plasma region<br />

A=-0.016903 C=-0.008637 E=-0.371×10 -3 G=-0.007896 I=-0.016162<br />

B=-0.01277 D=-0.004504 F=-0.003763 H=-0.012029<br />

Figure 3.12 – TFR isosurfaces on the plasma separatrix region for a<br />

40° sector with TBM and optimized ferromagnetic inserts<br />

Figure 3.13 – Detailed model used in the<br />

optimization of the ITER NBI magnetic field<br />

reduction system


064<br />

progress report<br />

2010<br />

Field (T)<br />

6.69<br />

4.63<br />

3.91<br />

2.58<br />

Field (T)<br />

5.15<br />

3.96<br />

2.76<br />

1.56<br />

×10 -3 RID<br />

Neuralizer<br />

Gap<br />

Beam source<br />

Figure 3.14 – Orthogonal to the beam<br />

residual magnetic field components at end<br />

of burning time and relating constraints<br />

along the ion beam path for the optimized<br />

NBI magnetic field reduction system<br />

×10 -3 26.2<br />

1.21<br />

By<br />

0.37<br />

Bz<br />

-0.15<br />

19.2 21.9 24.7 27.5 30.3<br />

Distance from yz plate (m)<br />

-0.82<br />

21.7 23.9 28.5 30.8<br />

Distance from yz plate (m)<br />

View from the top<br />

External walls<br />

Columns outside bioshield<br />

Iron doors<br />

NBI boxes<br />

Bioshield<br />

2° cylindrical wall<br />

NBI floor<br />

PFC TFC and AMFRS coils<br />

The magneto–static analysis was carried out by<br />

using a mixed approach which adopts the<br />

Biot–Savart integration for the plasma, PF coils and<br />

active coils circuital elements and employs a FEM<br />

approach for the detailed model of the passive<br />

ferromagnetic shiel<strong>di</strong>ng plates. The performed<br />

optimization of the active and passive magnetic field<br />

reduction system allowed the residual magnetic field<br />

along the beam path below the required level for<br />

operation to be reduced (fig. 3.14).<br />

Figure 3.15 – EM<br />

FEM of the ITER<br />

buil<strong>di</strong>ng complex<br />

Figure 3.16 – Magnetic field contour at EOB inside the ITER buil<strong>di</strong>ng at<br />

a vertical quota equal to the NBI axis level<br />

Assessment of the effects of the ferromagnetic<br />

material in the ITER buil<strong>di</strong>ng structures<br />

The stray magnetic field due to the ferromagnetic<br />

materials in the buil<strong>di</strong>ng surroun<strong>di</strong>ng the torus was<br />

evaluated inside the NBI system, the<br />

plasma region and outside the<br />

bio–shield structure by developing a full<br />

360° 3D electromagnetic model of the<br />

buil<strong>di</strong>ng complex (EMOBC) (fig. 3.15),<br />

inclu<strong>di</strong>ng the PF coils, the plasma, the<br />

two iron boxes and the active coils of the<br />

NBI magnetic field reduction system,<br />

the main buil<strong>di</strong>ng components with<br />

ferromagnetic materials (iron doors at<br />

the end of the port corridors, rebars in<br />

the buil<strong>di</strong>ng walls, floors, roof, basemat<br />

and seismic pit concrete).<br />

The analysis allowed the currents in the<br />

NBI active coils to be adjusted at several<br />

plasma scenario times, taking into<br />

account the effects due to the other NBI<br />

and the ferromagnetic materials all<br />

around. Moreover, the stray field due to<br />

the ferromagnetic content outside the<br />

vessel was calculated and the field<br />

perturbation produced on the plasma<br />

q=2 surface was evaluated with great accuracy in order to estimate the perturbation on the magnetic field from<br />

the axial symmetry that might produce unwanted plasma modes locking. Indeed, the evaluation of the very


technology programme (cont’d.)<br />

progress report<br />

2010<br />

065<br />

low (some gauss) stray field produced by the magnetization induced in the ferromagnetic materials on the<br />

plasma region required a careful analysis due to the presence of the high poloidal field produced by the plasma<br />

itself and by the PF coils that could not be excluded from the analysis itself.<br />

The stray field inside the whole main ITER buil<strong>di</strong>ng was also evaluated for several plasma scenario times<br />

(fig. 3.16) and the maximum magnetization of all the main ferromagnetic components was calculated (1.6 T<br />

for the NBI shiel<strong>di</strong>ng boxes, 0.55 T for the iron doors, 0.5 T/m 3 for the homogenised material inclu<strong>di</strong>ng the<br />

rebars and the concrete of the buil<strong>di</strong>ng).<br />

Pre–compression rings final design qualification<br />

The ITER pre–compression rings activities continued in <strong>ENEA</strong> Frascati with the fifth ultimate tensile strength<br />

(UTS) test performed on a ring scaled mock–up with a <strong>di</strong>ameter of 1 meter (fig. 3.17) (ITER Contract<br />

09–4300000015) [3.8,3.9]. This was the latter of six UTS tests on six <strong>di</strong>fferent mock–ups. Four rings were<br />

manufactured with the vacuum pressure impregnation (VPI) technique developed and optimized in <strong>ENEA</strong><br />

while the other two were produced by the filament wet win<strong>di</strong>ng<br />

(WW) industrial conventional process.<br />

The mock–ups were <strong>di</strong>mensionally checked and x–rays surveyed<br />

before tests. Then UTS tests were carried out by loa<strong>di</strong>ng the rings<br />

with ra<strong>di</strong>al <strong>di</strong>splacement increments of 0.1 mm by means of the<br />

ring hydraulic testing facility in <strong>ENEA</strong> Frascati and following as<br />

close as possible the standard test method ASTM D3039 for<br />

tensile properties of polymer matrix composite materials.<br />

UTS tests showed an average strength of 1550 MPa (mean hoop<br />

stress in the cross section) and constant tensile modulus of<br />

elasticity up to failure. UTS obtained on the VPI rings was<br />

1584 MPa, higher than UTS on the WW rings, 1485 MPa.<br />

Figure 3.17 – Pre–compression ring<br />

<strong>di</strong>smantling after test<br />

The volumetric glass content of the rings was measured on some of the rings after test, resulting in an average<br />

of 70% both for VPI and WW rings.<br />

The testing activity continued with a stress relaxation test performed on a VPI ring mock–up for 210 days at<br />

a stress level of 950 MPa. The mock–up showed a stress relaxation of less than 0.5% and a residual strain of<br />

0.02% after test. No defects were detected by x–rays after test.<br />

Another WW ring was then manufactured and will be stress relaxation tested during 2011. Characterization<br />

of the ring composite material has been completed with creep, shear and compression tests.<br />

On the basis of the <strong>ENEA</strong> R&D activity, at the end of 2010 F4E launched a call for tender for the<br />

procurement of the ITER full scale pre-compression rings where <strong>ENEA</strong> will be involved to qualify preliminary<br />

scaled rings.<br />

3.4 Remote Handling and Metrology<br />

ITER in vessel viewing system<br />

<strong>ENEA</strong> developed and tested a prototype of a laser in vessel viewing and ranging system (IVVS), that uses the<br />

amplitude modulated laser radar concept and is based on an intrinsically ra<strong>di</strong>ation resistant concept and<br />

architecture to withstand the severe ITER con<strong>di</strong>tions. It already approaches the target specification requested<br />

for ITER, although its present layout is not capable to withstand all the ITER environmental con<strong>di</strong>tions.<br />

In late 2008, <strong>ENEA</strong> won a grant launched by F4E for the conceptual design of the final ITER in–vessel<br />

inspection prototype and the assessment of the present IVVS prototype. The activity started in April 2009 and<br />

continued in 2010 to evaluate the potential application of the <strong>ENEA</strong> IVVS prototype for ITER in–vessel<br />

inspection and then produce the conceptual design of an IVVS system compliant with all the ITER<br />

requirements and the related test bed. The work has been <strong>di</strong>vided into three main tasks.


066<br />

progress report<br />

2010<br />

• The execution of laboratory tests with the <strong>ENEA</strong> IVVS mock–up in order to verify that the performance<br />

of the mock–up are matching (or at which level are approaching) those required for the final application in<br />

ITER<br />

• The assessment of the expected viewing/metrology capability of the IVVS in the ITER con<strong>di</strong>tions,<br />

• The conceptual designs of an IVVS probe prototype and related test bed, in preparation of the future<br />

procurement and testing activities. They take into account all the very severe environmental con<strong>di</strong>tions of<br />

ITER during the inspection.<br />

The 2010 year was mainly devoted to the activities described in the following.<br />

Vibration effects on IVVS images and vibration correction<br />

method. As the IVVS probe will be installed on a de<strong>di</strong>cate<br />

deployer to be inserted in ITER, vibrations may arise in the<br />

probe due to the tilt movement of the scanning prism. A<br />

de<strong>di</strong>cate test campaign was carried out to evaluate how<br />

viewing and metrology are affected by probe vibration at low<br />

frequency (f


technology programme (cont’d.)<br />

progress report<br />

2010<br />

067<br />

The mechanical design of the IVVS probe was also revised and finalized<br />

to the ITER environmental requirements. It has been improved with a<br />

<strong>di</strong>fferent actuating system for the scanning prism, a new step focus<br />

actuating system and a revision of materials and components due to the<br />

stringent ITER requirements. The present gearing chain designed and<br />

realized to transmit the tilt and the pan movements to the prism by<br />

means of step motors has be completely removed in the new design and,<br />

in order to meet the high magnetic field requirement, it has been<br />

replaced with rotation actuators driven by a couple of ultrasonic<br />

piezo–motors (see fig. 3.22). The softness of movement reachable with<br />

such motors is expected to sidestep the vibrations due to the scanning<br />

prism movement. Commercial ultrasonic piezo–motors are compact,<br />

maintenance–free, intrinsically non–magnetic and vacuum–compatible<br />

but they must be customized to work at 120 °C and to be backed at<br />

200–240 °C. Linear piezo–motors will be also adopted to operate the<br />

new step focus system.<br />

The <strong>di</strong>mensional stability of the mechanical structure will be obtained<br />

by using antimagnetic steel alloys such as Invar or Kovar, which have a<br />

thermal expansion close to fused silica, which is the material selected to manufacture prism and lenses.<br />

Ceramic materials will also be used for particular components, such us bearings and collars.<br />

Assessment of the expected viewing/metrology capability of the IVVS in the ITER. In order to realize an<br />

assessing tool, a 3D FEM based software has been realized to satisfy the following requirements:<br />

• to import from F4E “CAD” data of ITER in vessel surfaces<br />

• to originate all the positions and orientations of the IVVS heads<br />

• to find the ITER in vessel surfaces elements visible from the scanning heads<br />

• to <strong>di</strong>stinguish them from the elements hidden to a scanning head because of its position and orientation<br />

• to numerically implement the quality functions describing the IVVS performance<br />

• to find the quality of each element of ITER in vessel surfaces<br />

• to produce quality maps with expected IVVS viewing and metrology capabilities<br />

• to optimize number and position of scanning heads necessary to best cover the whole inner surface of the<br />

ITER vessel.<br />

A contract has been signed with Enginsoft Spa to develop this software, which was delivered to F4E the last<br />

September 23th.<br />

The beta release of this software had been tested by <strong>ENEA</strong> in Frascati,<br />

and produced quality maps of ITER in vessel surfaces.<br />

In the meantime, <strong>ENEA</strong> had developed an optimization strategy, whose<br />

specification was emitted in the first half of july.<br />

The beta release of this software had been installed in F4E Barcelona on<br />

August the 16th, after which a training on job was provided by <strong>ENEA</strong><br />

Frascati scientists, the first week in F4E Barcelona, the following ones at<br />

the Frascati Research Center.<br />

At the end of the debug activities, the final release of this software took<br />

place.<br />

Since then, this software is being employed by <strong>ENEA</strong> in conjunction with<br />

F4E to the purpose of producing quality maps (see fig. 3.23) and<br />

optimizing the IVVS prototype and its placement in ITER.<br />

Figure 3.22 – Mechanical design of<br />

the new IVVS scanning head<br />

Figure 3.23 – Example of quality map showing the standard deviation<br />

of the IVVS range measurement on the ITER geometry for a given head<br />

position


068<br />

progress report<br />

2010<br />

Figure 3.24 – Picture of the ITER Mock–up<br />

assembled at FNG<br />

Front casing<br />

Front insulation<br />

1st win<strong>di</strong>ng<br />

2nd win<strong>di</strong>ng<br />

Side and rear<br />

casing<br />

1st layer SB<br />

1981 1982<br />

Back of SB<br />

2041 2047<br />

CuCrZr<br />

Rest of coil<br />

Thermal shield IVVS<br />

Side and rear insulation VV outer shell<br />

VV inner shell<br />

3rd layer<br />

FW<br />

Manifolds<br />

First wall<br />

Figure 3.25 – The ra<strong>di</strong>al section on the inboard<br />

side of the latest ITER Alite model<br />

Figure 3.26 – MCNP model (equatorial section<br />

(z=0))<br />

3.5 Neutronics<br />

Neutronics shiel<strong>di</strong>ng experiment on a mock–up of ITER:<br />

dose measurement in the magnet coils<br />

In the ITER design it is important to minimize the<br />

uncertainty in the estimates of the nuclear loads; in<br />

particular, the nuclear heating of the TF coils in the<br />

inboard leg is the most critical. To this purpose, accurate<br />

ra<strong>di</strong>ation transport calculations of the shiel<strong>di</strong>ng is<br />

requested. These calculations are very challenging, since the<br />

ra<strong>di</strong>ation attenuation from the first wall to the TF coils can<br />

be many orders of magnitude and, at the same time,<br />

accuracy of the order of ±10% or better is required. The<br />

calculation must be benchmarked as far as possible against<br />

suitable experiments to attain the necessary validation of<br />

nuclear data and codes used.<br />

To check whether the present design calculations are able to<br />

evaluate the shiel<strong>di</strong>ng properties of the ITER shield at<br />

inboard side with sufficient accuracy and reliability, an<br />

experiment was realized at the Frascati Neutron Generator<br />

(FNG) of <strong>ENEA</strong>–Frascati. The experiment was<br />

commissioned by ITER IO.<br />

In this experiment, a mock–up of ITER inboard shield,<br />

vacuum vessel and TF coils was replicated and irra<strong>di</strong>ated by<br />

14–MeV neutrons (fig. 3.24). The mock–up also included<br />

the borated steel plates presently foreseen by the design as<br />

well as some pieces of the actual superconducting cables,<br />

which represented the actual experimental region (TF coils).<br />

The final mock–up <strong>di</strong>mensions and materials compositions<br />

were based upon the <strong>di</strong>mensions and materials of the latest<br />

version of the Alite Monte Carlo n–Particle (MCNP) model<br />

of ITER (fig. 3.25).<br />

The resulting nuclear heating in the TF coils was measured<br />

by using state–of–the–art experimental techniques (high<br />

sensitivity thermoluminescent dosimeters), and compared<br />

with calculations performed with the MCNP code and the<br />

ITER reference nuclear data library FENDL.–2.1. The<br />

experiment also included the measurement of selected<br />

reaction rates along the central axis of the mock–up as well<br />

as in the coil region. These measured quantities were<br />

compared with the results of calculations too.<br />

A very detailed model of the experimental set–up was used (fig. 3.26). In this way, the highest level of accuracy<br />

was attained in the ratio between the calculated and the experimental quantities (C/E ratio), thus provi<strong>di</strong>ng<br />

fundamental information about the dose absorbed by the superconducting inner coils. For example, for the<br />

nuclear heating a slight overestimation is observed within the C/E error (±10%) in the coil region. This<br />

accuracy in the C/E ratio was never reached in previous experiments.<br />

Moreover, regar<strong>di</strong>ng the uncertainty margins in the FENDL–2.1/MCNP–5 pre<strong>di</strong>ction, it can be concluded<br />

that:<br />

• the fast neutron flux is calculated within an uncertainty margin of about ±15% in the ITER shiel<strong>di</strong>ng<br />

blanket and the magnet region.<br />

• the thermal neutron flux is calculated within an uncertainty margin of about ±15% in the ITER shiel<strong>di</strong>ng<br />

blanket, vacuum vessel, up to the toroidal field coils.


technology programme (cont’d.)<br />

progress report<br />

2010<br />

069<br />

• the nuclear heating is calculated within an uncertainty margin of about ±10% in the spatial region of the<br />

ITER shiel<strong>di</strong>ng blanket and vacuum vessel, and within an uncertainty margin of about ±10% in the region<br />

of the toroidal field coil with a total uncertainty on the C/E ratio which is always


070<br />

progress report<br />

2010<br />

15 cm ra<strong>di</strong>us); b) neutron and gamma spectra at the<br />

detector location; c) analysis of the components of the<br />

collided neutron spectrum.<br />

The estimation of neutron spectra and<br />

collided–to–uncollided ratio(C/U) is useful to evaluate<br />

the neutronic performance of the HRNS collimator in<br />

both configurations (i.e. variation of the background with<br />

the <strong>di</strong>stance inside the cavity) and to characterize the<br />

ra<strong>di</strong>ation field inside it. Figure 3.29 shows the C/U values<br />

for 15 cm and 5 cm ra<strong>di</strong>us: the latter option is more<br />

effective in the collimation, especially in the front regions.<br />

Neutron spectra for 15 cm and 5 cm ra<strong>di</strong>i at the detector<br />

position are shown in figure 3.30.<br />

Figure 3.28 – The HRNS inside the port plug: in pale<br />

blue the concrete collar<br />

Collided/uncollided<br />

1.6<br />

1.2<br />

0.8<br />

0.4<br />

0.0<br />

800<br />

5 cm ra<strong>di</strong>us<br />

15 cm ra<strong>di</strong>us<br />

1200<br />

1600<br />

Distance from the torus axis (cm)<br />

Figure 3.29 – Collided to uncollided ratio at <strong>di</strong>fferent<br />

positions along the HRNS collimator: 15 cm (red) and<br />

5 cm (black) ra<strong>di</strong>us<br />

Neutron flux (n cm2/MeV/source n)<br />

10 -10<br />

10 -12<br />

10 -14<br />

0 10 20<br />

Energy (MeV)<br />

Figure 3.30 – Neutron spectra at the detector position<br />

D for 15 cm (dotted blue) and 5 cm (straight black)<br />

ra<strong>di</strong>us<br />

In order to fully characterize the ra<strong>di</strong>ation field at the<br />

detector position D, photon flux and spectra have been<br />

evaluated as well. The absolute values of the gamma flux<br />

are: 5.32×10 8 γ/cm 2 /s and 3.29×10 9 γ/cm 2 /s for 5 cm<br />

and 15 cm ra<strong>di</strong>us respectively .<br />

The collided spectrum at the detector position has been<br />

analyzed in order to isolate the contribution due to<br />

<strong>di</strong>fferent zones of the torus (inboard and outboard zones).<br />

The results obtained show that a large contribution to the<br />

collided neutron spectrum is due to the particles scattered<br />

only by the inboard side, which penetrate into the<br />

collimator, thus reaching the detector position. These<br />

results confirm the effectiveness of the port plug shiel<strong>di</strong>ng<br />

capability [3.11].<br />

Three–<strong>di</strong>mensional neutronic analysis of the ITER<br />

in–vessel coils<br />

In the frame of the contract ITER/CT/09/4100001120<br />

a complete neutronic analysis has been performed for the<br />

design of the in–vessel coil systems by using the MCNP5<br />

code in a full 3–D geometry. A detailed geometry of edge<br />

localised mode (ELM) and vertical stabilizing (VS) coils<br />

based on the last design specifications has been integrated<br />

into the last version of 40° ITER Alite MCNP model<br />

(fig. 3.31).<br />

cm<br />

800<br />

400<br />

0<br />

VS upper<br />

Upper ELM<br />

Central<br />

ELM<br />

Lower<br />

ELM<br />

-400<br />

VS lower<br />

Figure 3.31 – Vertical section of Alite–4<br />

MCNP model with In–vessel coils<br />

-800<br />

-800<br />

-400<br />

0<br />

cm<br />

400 800


technology programme (cont’d.)<br />

progress report<br />

2010<br />

071<br />

In a first stage, the blanket/manifold original description<br />

was not mo<strong>di</strong>fied: the coils cut across the interposing<br />

structures. In a second stage, manifolds have been<br />

simulated in front of poloidal coils located behind gaps<br />

(fig. 3.32). Poloidal, ra<strong>di</strong>al and toroidal variations of all<br />

relevant nuclear parameters are provided, as well as<br />

detailed nuclear heating tables useful for thermal analysis.<br />

In the original configuration (without front manifolds) the<br />

total nuclear power deposited on ELM coils is ∼3 MW. The<br />

peak nuclear parameters obtained on the conductor are:<br />

nuclear heating 1.7 W/cm 3 and damage 0.4 dpa.<br />

Concerning the insulator: maximum cumulative dose is<br />

4210 MGy, dose rate 211 Gy/s and neutron fast fluence<br />

3.45×10 20 n/cm 2 . For stainless steel components, the<br />

He–production peak is 6.5 appm.<br />

Nuclear parameters show a great spatial variation. Peak<br />

values are found in limited zone close to the blanket gaps:<br />

figure 3.33 shows the toroidal profile of the nuclear heating<br />

in the upper toroidal ELM front components. The peak<br />

corresponds to the poloidal gap. An increase of about 50%<br />

is obtained in this zone with respect to the parts of the coils<br />

far from the gap.<br />

Figure 3.34 shows the ra<strong>di</strong>al profile of the nuclear heating<br />

in CuCrZr in the toroidal coils of lower ELM coils and<br />

connecting poloidal segments with and without a front<br />

manifold. Without a front manifold, the ratio between<br />

nuclear heating values in front and rear coils is about 0.3.<br />

By comparing top and bottom toroidal results, the nuclear<br />

heating in the bottom coils shielded by blanket modules is<br />

about 50% of that in the top. With a front manifold, the<br />

ra<strong>di</strong>al profile exhibits a steeper variation: the ratio between<br />

rear and front coil nuclear heating values drops to 0.2. The<br />

increase due to the manifold is about 60% due to the<br />

presence of water and large void space. The increase in the<br />

other quantities is lower than that in nuclear heating except<br />

for Helium production in the zones behind the manifold.<br />

Regar<strong>di</strong>ng the impact on the vacuum vessel reweldability,<br />

the He–production value does not exceed that of the<br />

original configuration (max He–production 0.6 appm).<br />

With heterogeneous manifold located in front of the<br />

poloidal coils, the He–production exceeds the limit but<br />

only in zones where the rewel<strong>di</strong>ng is not foreseen.<br />

Comparing the nuclear loads on CuCrZr and C10700 for<br />

the conductor and of spinel and MgO for the insulator, no<br />

significant variations are found. Hence, the neutronic loads<br />

on these materials can be considered as non relevant issues<br />

for selecting these components.<br />

Activation analysis has been carried–out with FISPACT<br />

2007 by using the neutron spectra calculated in 3–D with<br />

MCNP5 and the safety scenario SA2. Total neutron fluxes<br />

vary from 7.3×10 12 n/cm 2 /s in the more shielded segment<br />

to 5.1×10 13 n/cm 2 /s on the nose of the connecting coils in<br />

the gap between blanket modules. Figure 3.35 shows the<br />

dose rate versus time after irra<strong>di</strong>ation in the front part of<br />

the connecting segment. At the shutdown, peak specific<br />

Poloidal segment of ELM coils<br />

Figure 3.32 – Ra<strong>di</strong>al section of MNCP model of ITER.<br />

Poloidal ELM coils in the configuration a) without<br />

front manifold and b) with manifolds<br />

Nuclear heting (W/cm 3 )<br />

1.6<br />

1.2<br />

0.8<br />

0.4<br />

0.0<br />

SS support-front<br />

SS envelope<br />

MgO insulator<br />

Water<br />

CuCrZr<br />

conductor<br />

0 30 60 90 120<br />

Toroidal position (cm)<br />

Figure 3.33 – Nuclear heating toroidal profile of the<br />

front coil and front support of upper ELM toroidal<br />

top coils<br />

Nuclear heating (W/cm 3 )<br />

2<br />

1<br />

0<br />

4<br />

Tor top lower ELM<br />

Tor bottom lower ELM<br />

Pol no front manifold<br />

Pol + front manifold<br />

8 12 16 20<br />

Distance from the VV (cm)<br />

Figure 3.34 – Nuclear heating on CuCrZr ra<strong>di</strong>al<br />

profile in lower ELM coils and poloidal connecting<br />

segments with and without front manifold<br />

Contact dose rate (sv/h)<br />

10 4 CuCrZr<br />

C10700<br />

MgO<br />

10 2<br />

Spinel<br />

SS<br />

10<br />

10 -2<br />

10 -4<br />

10 -6 Min Hour Days Month Year<br />

10 -8 10 -4 10<br />

10 2<br />

Time after irra<strong>di</strong>ation (years)<br />

Figure 3.35 – Peak contact dose rate versus time<br />

after irra<strong>di</strong>ation in the most irra<strong>di</strong>ated coil


072<br />

progress report<br />

2010<br />

activity varies from 5.25×10 12 Bq/kg in stainless steel to 5.2×10 13 Bq/kg in C10700, maximum dose rate and<br />

decay heat are 1.2×10 4 Sv/h and 9.6 W/kg in Spinel. After 50 years from the shutdown peak specific activity,<br />

dose rate and decay heat are 7.6×10 9 Bq/kg, 102 mSv/h and 0.08 mW/kg respectively in CuCrZr. At me<strong>di</strong>um<br />

cooling times the activation of CuCrZr is higher than of that C10700 (the maximum ratio is 2) because of<br />

Cobalt. Except at very short cooling times, the insulator activation is lower than that of conductor and SS<br />

components and is dominated by the impurities. Copper resistivity increase at the shutdown varies in the range<br />

33.6–276.7 pΩm (resistivity of pure copper is 17 nΩm, at T=20°C) due to transmutation in Ni, Co and Zn.<br />

In the more shielded segments, the activation and transmutation are about one order of magnitude lower than<br />

the peak. The impact of the front manifold on the activation of the poloidal components is within a factor 2<br />

and depends on the material and cooling time. The complete inventory is provided to perform the safety<br />

analysis and waste classification [3.12, 3.13].<br />

Neutron and gamma spectra behind ITER blanket modules and in <strong>di</strong>vertor<br />

The installation of sensors behind ITER blanket modules and in the <strong>di</strong>vertor region is under study. For this<br />

reason, knowledge of the ra<strong>di</strong>ation field (i.e. neutron and secondary gamma spectra) is required. For this scope<br />

3–D ra<strong>di</strong>ation transport simulations have been performed using MCNP5 code with FENDL2.1.<br />

Z axis<br />

6<br />

4<br />

2<br />

-1<br />

-4<br />

Profile<br />

Neutron and gamma fluxes and spectra have been calculated in<br />

forty–five positions (fig. 3.36) assuming neutron production<br />

from a 500 MW DT plasma. The positions of the detectors in<br />

outboard regions have been varied toroidally to evaluate the<br />

impact on the ra<strong>di</strong>ation field of the port plug and the shiel<strong>di</strong>ng<br />

capability of the blanket modules.<br />

In the <strong>di</strong>vertor region, the maximum total neutron flux is found<br />

in the dome zone (5.5×10 13 n/cm 2 /s) and the minimum one is<br />

found at the bottom of the outer vertical target. The gamma<br />

flux varies between 5.7×10 12 γ/cm 2 /s and 3.6×10 13 γ/cm 2 /s.<br />

Behind blanket modules, maximum fluxes are calculated in the<br />

gaps between the central outboard modules (7.9×10 12 n/cm 2 /s<br />

and 4.6×10 12 γ/cm 2 /s). The fluxes drop of one order of<br />

magnitude at the top of the machine.<br />

The effect of the <strong>di</strong>fference between port plug and blanket<br />

module is moderate. In fact, in the equatorial port zone the<br />

toroidal variation is ≤12% on the neutron flux and ∼25% on the<br />

gamma flux. The effect is higher in the upper port zone (within<br />

a factor 2).<br />

The poloidal behaviour of the neutron flux follows the neutron<br />

R axis<br />

current profile except in the regions close to the equatorial<br />

Figure 3.36 – Positions of the detectors midplane. This is mainly due to the variability of blanket’s<br />

shiel<strong>di</strong>ng thickness. The ra<strong>di</strong>al profile of the flux is very<br />

sensitive to blanket front attenuation: by moving the detectors<br />

located close to the midplane 8 cm toward the plasmas, the neutron flux doubles as compared to the reference<br />

position [3.14].<br />

Neutronic analysis of ITER <strong>di</strong>vertor rails<br />

Nuclear heating for a 500 MW DT plasma, helium production and dpa at end–of–life have been calculated<br />

in several positions of the <strong>di</strong>vertor rails and surroun<strong>di</strong>ng components by using the MCNP5 code in a three<br />

<strong>di</strong>mensional geometry. Maps in two poloidal inner and in five poloidal sections are provided.<br />

Higher values of nuclear heating, He production and dpa are found in the inner zone, especially on the top<br />

corner of inner cover plate because of the streaming through the gaps between cassettes, values are shown in<br />

figure 3.37. In the most irra<strong>di</strong>ated outboard zone the obtained values are lower by one order of magnitude as<br />

compared to the inboard quantities.


technology programme (cont’d.)<br />

progress report<br />

2010<br />

073<br />

Nuclear heating<br />

(kW/m 3 )<br />

Bolt 63.1<br />

Spring<br />

washer<br />

73.3<br />

Insert 54.4<br />

Bolt 27.1<br />

Spring<br />

washer<br />

34.9<br />

Insert 19.8<br />

He Production at EOL<br />

(appmax10 -2 )<br />

Bolt 43.3<br />

Spring<br />

washer<br />

48.3<br />

Insert 6.9<br />

Bolt 17.3<br />

Spring<br />

washer<br />

21.9<br />

Insert 4.5<br />

Dpa at EOL (dpa x10 -2 )<br />

Bolt 15.3<br />

Spring<br />

washer<br />

17.0<br />

Insert 16.1<br />

Bolt 7.1<br />

Spring<br />

washer<br />

8.6<br />

Insert 6.5<br />

Figure 3.37 – Nuclear heating, helium production and dpa in inner rail close to the cassette gap at end–of–life (EOL). Generic<br />

scoring cells are spheres. Bolt cells are cylinders laying along ra<strong>di</strong>al <strong>di</strong>rection<br />

Nuclear responses in the bolts, inserts, spring washers<br />

and shear keys have been calculated in some<br />

representative positions. To estimate the expected values<br />

in other zones, conversion factors taking into account the<br />

<strong>di</strong>fferent materials’ responses are provided as well [3.15].<br />

Development of a high resolution compact neutron<br />

spectrometry using <strong>di</strong>amond detectors<br />

An EFDA contract was assigned to <strong>ENEA</strong>–Frascati to<br />

7.5<br />

develop a compact HRNS using <strong>di</strong>amond detectors. The 0 4 8 12 16<br />

scope of the task is to demonstrate the capability of<br />

Deposited energy (MeV)<br />

artificial <strong>di</strong>amond detectors to operate as neutron<br />

spectrometers with high resolution in the neutron energy Figure 3.38 – Experimental response functions<br />

range 5.7–20 MeV. The <strong>di</strong>amond detector response<br />

functions are necessary in order to characterize the <strong>di</strong>amond detector and to archieve the best possible energy<br />

resolution and the widest neutron spectroscopy energy range. The response functions obtained for the<br />

<strong>di</strong>amond detector will be used to unfold the line integrated pulse height spectra measured along the various<br />

lines of sight of the ITER RNC by using the technique of a double reconstruction, in space and energy.<br />

A single crystal <strong>di</strong>amond detector was exposed to quasi mono–energetic neutron fields in the energy range<br />

from 5 MeV to 20.5 MeV produced by the Van de Graaff neutron generator of the EC–JRC–IRMM.<br />

Response functions were measured for the first time for neutron energies above 14 MeV (fig. 3.38). The pulse<br />

height spectra showed sharp peaks at specific energies. These peaks result from neutron induced charged<br />

particle reactions occurring in carbon at <strong>di</strong>fferent neutron energies. The centroid of the peaks due to the<br />

12 C(n,α) 9 Be reaction permitted, by means of the reaction Q–value (–5.7 MeV), to point out an excellent<br />

linearity of the detector response versus neutron energy and an extremely good intrinsic energy resolution of<br />

about 56 keV at full width at half–maximum.<br />

16.5<br />

10 -4<br />

10 -6<br />

10 -8<br />

20.5<br />

Normalized<br />

response<br />

Neutron energy<br />

(MeV)<br />

Measurement of Ti profiles with the ITER ra<strong>di</strong>al neutron camera<br />

The study of the capabilities of the ITER RNC as an ion temperature (Ti) profile <strong>di</strong>agnostic has been<br />

completed (EFDA task WP08–DIAG–01–06). Two measurement approaches have been investigated under the<br />

assumption of a) purely thermal plasma and b) use of liquid scintillator detectors. The first approach relies on<br />

the exploitation of the spectrometric capabilities of liquid scintillator detectors through the unfol<strong>di</strong>ng of line<br />

integrated-spectra. Results suggest that, under the above assumptions, the RNC can indeed work as a<br />

multichannel neutron spectrometer [3.16] and provide Ti profile measurements with accuracy and time<br />

resolution within the ITER requirements. An example of Ti reconstruction in an ITER plasma scenario (#4)<br />

characterized by an internal transport barrier is given in figure 3.39: Ti (shown as a function of the magnetic<br />

flux coor<strong>di</strong>nate ψ) is reconstructed within 10% accuracy even in presence of a strong Ti gra<strong>di</strong>ent <strong>di</strong>scontinuity.<br />

The second approach is based on the use of the measurements of the integrated flux and other plasma<br />

parameters. In this case it is not possible to match the measurement requirements, mainly because of the


074<br />

progress report<br />

2010<br />

T(keV)<br />

30<br />

20<br />

Δt=1 s<br />

a)<br />

Original<br />

Reconstructed<br />

%<br />

20<br />

10<br />

Δt=1 s<br />

Precision<br />

Accuracy<br />

b)<br />

Figure 3.39 – Ion temperature<br />

profile reconstruction using<br />

unfol<strong>di</strong>ng of RNC line–<br />

integrated pulse height spectra:<br />

a) comparison between original<br />

and reconstructed Ti profiles; b)<br />

accuracy and precision in the<br />

reconstruction<br />

10<br />

0<br />

0<br />

0.4<br />

ψ<br />

0.8<br />

1<br />

0<br />

0<br />

0.4<br />

ψ<br />

0.8<br />

1<br />

T(keV)<br />

20<br />

10<br />

Original<br />

Reconstructed<br />

a)<br />

%<br />

20<br />

10<br />

Precision<br />

Accuracy<br />

b)<br />

Figure 3.40 – Ion temperature<br />

profile reconstruction using<br />

RNC integrated flux measurements<br />

and other plasma<br />

parameters’ measurements: a)<br />

comparison between original<br />

and reconstructed Ti; b)<br />

accuracy and precision in the<br />

reconstruction<br />

0<br />

0<br />

0.4<br />

ψ<br />

0.8<br />

1<br />

0<br />

0<br />

0.4 ψ 0.8 1<br />

0.2<br />

0.1<br />

a)<br />

strong variability of the neutron reactivity with temperature, and<br />

because of the accuracy foreseen for density, effective charge and<br />

impurity density profiles measurements. An example of the Ti<br />

reconstruction is given in figure 3.40.<br />

0.0<br />

0.0 0.4 0.8<br />

r/a<br />

0.4<br />

0.2<br />

0.0<br />

0.0 0.4 0.8<br />

r/a<br />

Figure 3.41 – a) Average reconstructed<br />

fuel ratio profile (inclu<strong>di</strong>ng error bars); b)<br />

precision (dashed) and accuracy (solid) of<br />

the reconstruction<br />

b)<br />

Measurement of fuel ratio profiles with the ITER ra<strong>di</strong>al neutron<br />

camera<br />

The study of the capabilities of the ITER RNC equipped with<br />

liquid scintillator detectors as a <strong>di</strong>agnostic for the fuel ratio (n T<br />

/n D<br />

,<br />

ratio of the tritium to deuterium density) is being investigated in the<br />

frame of an EFDA task (WP10–DIA–01–03). To <strong>di</strong>agnose the<br />

n T<br />

/n D<br />

profile, the RNC should be able to provide simultaneously<br />

DD (2.5 MeV) & DT (14 MeV) neutron emissivity profiles<br />

measurements and a measurement of the ion temperature profile;<br />

the success of the measurement strongly relies on the background<br />

due to scattered 14 MeV neutrons that, depen<strong>di</strong>ng on its<br />

magnitude, may preclude the measurement of the DD spectral<br />

component. The following measurement procedure is proposed<br />

and applied to ITER scenario 2: 1) unfol<strong>di</strong>ng of RNC<br />

line–integrated spectra to recover separated DD and DT brightness<br />

components. 2) Spatial inversion of DD and DT brightness signals<br />

to determine separate DD and DT emissivites. 3) Determination of the ion temperature profile. Montecarlo<br />

calculations (using MCNP) have been performed for a representative subset of the 45 RNC lines of sight, in<br />

order to characterize the background due to 14 MeV scattered neutrons at the RNC detectors' position. The<br />

calculations have been carried out by inclu<strong>di</strong>ng the RNC in the latest MCNP 40° ITER model (Alite–4). The<br />

results in<strong>di</strong>cate that the RNC might measure flat n T<br />

/n D<br />

profiles with values between 0.01 and 0.1 (with 20%<br />

accuracy and precision and 100 ms time resolution) up to r/a < ∼0.8. An example is shown in figure 3.41 for


technology programme (cont’d.)<br />

progress report<br />

2010<br />

075<br />

n T<br />

/n D<br />

=0.1. The maximum measurable n T<br />

/n D<br />

can be extended up to ∼0.2 for r/a < ∼0.4. The possibility to<br />

measure non–flat n T<br />

/n D<br />

profiles has been also demonstrated but requires further investigation.<br />

3.6 Materials<br />

Development of a multi–scale methodology for composite structural modelling and validation of modelling<br />

procedure by mechanical testing<br />

In the field of computational material science the multiscale methodology plays an important role. It is based<br />

on the hierarchical concept that there is a strong interconnection between phenomena that happen on<br />

<strong>di</strong>fferent length and time scales. In the field of composite materials, the approach is applied to the description<br />

of the behaviour of the constituents, i.e. fibre and matrix.<br />

In this work a constitutive model for a balanced plain weave fabric was developed. This model, starting from<br />

geometrical and mechanical parameters of the single constituents (fibre and matrix) determines the effective<br />

moduli of the representative unit cell. This model was implemented into the general purpose finite element<br />

program Abaqus, thus buil<strong>di</strong>ng a specific user subroutine.<br />

The last part of this job was to determine a material failure mechanism theory for the balanced plain weave<br />

architecture that was implemented in the same specific user subroutine. The pre<strong>di</strong>ction of the failure at each<br />

increment of the load was obtained by using a quadratic failure criterion, applied to the strains with stiffness<br />

and strength reduction scheme to account for<br />

damage within the yarns.<br />

The subroutine is an augmentation for any<br />

commercial finite element code, thus giving the<br />

possibility to deal with any composite material<br />

made with balanced plain weave fabric, provided<br />

that the mechanical properties of the single<br />

constituents and the specific failure mechanisms<br />

are known.<br />

In figure 3.42 an example problem is shown that<br />

has been solved by using this standard user<br />

subroutine. We have stu<strong>di</strong>ed a square panel of side<br />

600 mm and thickness 3.43 mm where all the<br />

edges are clamped and the load is a uniform<br />

pressure applied to the bottom surface.<br />

Start matrix failure<br />

in the yarn<br />

Green= fill matrix failure<br />

Yellow= warp matrix failure<br />

Pressure (MPa)<br />

Green= fill fiber failure<br />

Yellow= warp matrix failure<br />

1<br />

Start fiber failure<br />

in the yarn<br />

a) Plain weave<br />

Fill yarn<br />

Fill yarn<br />

No damage model<br />

TSAI-WJ criterion<br />

0<br />

0 10 20 40 40<br />

Displacement at the center (mm)<br />

Figure 3.42 – Graphical visualization of the results<br />

3.7 Safety and Environment, Power Plant Conceptual Stu<strong>di</strong>es and Socio<br />

Economics<br />

Several fusion safety issues have been faced throughout 2010. Some of them are still going on and final results<br />

will be achieved in 2011. The tasks are described in the following.<br />

Dust mobilization stu<strong>di</strong>es<br />

For ITER fusion safety stu<strong>di</strong>es one of the most important and potentially dangerous deviations from the<br />

normal operations is the loss of vacuum accident (LOVA) in the plasma chamber, where the presence of<br />

hydrogen isotopes and dust coming in contact with air oxygen might produce con<strong>di</strong>tions overcoming explosive<br />

concentration limits. In this frame a literature research on dust mobilization during LOVA highlighted some<br />

gaps in the experimental data base concerning mobilization in sub–atmospheric pressures. To overcome this<br />

limitation a preliminary design was prepared for an appropriate channel facility operating under vacuum and<br />

of reduced <strong>di</strong>mensions, which would allow the dust mobilization behaviour to be investigated in a simple flow<br />

geometry and with restrained costs [3.17].


076<br />

progress report<br />

2010<br />

Cell Reynolds number (log)<br />

10 6 P=0.1×10 5<br />

P=0.2×10 5<br />

P=0.3×10 5<br />

P=0.5×10 5<br />

P=0.8×10 5<br />

P=1×10 5<br />

104<br />

102<br />

0<br />

1 2<br />

x<br />

Figure 3.43 – Reynolds number along the<br />

central axis for a horizontal cylinder, for<br />

pressure range 0.1–1×10 5 Pa<br />

Figure 3.44 – Set–up for the <strong>di</strong>agnostic<br />

test of the dust mobilization<br />

The work was done in the frame of the F4E Grant<br />

F4E–2008–GRT–01–01 (ES–SF) and dealt with the design and<br />

instrumentation of a channel flow facility and the proposal of an<br />

experimental R&D program on dust mobilization.<br />

The fluid–dynamical analysis showed that a cylindrical vessel,<br />

vertical or horizontal with a high length–ra<strong>di</strong>us ratio (1 or 2 m<br />

length/height vs 0.333 m ra<strong>di</strong>us) and restrained <strong>di</strong>mensions, such<br />

that it can be hosted in a laboratory room, is suitable to carry out a<br />

valuable study on the gas – dust particles interaction and dust<br />

mobilization. The k–ε turbulence model has been adopted to<br />

simulate the flow field inside the channel, and stationary con<strong>di</strong>tions<br />

have been extensively investigated. With the shape proposed and<br />

under the boundary con<strong>di</strong>tions imposed, the turbulence is<br />

maintained in the main part of the channel (fig. 3.43).<br />

In ad<strong>di</strong>tion, the most suitable <strong>di</strong>agnostics to characterize the dust<br />

concentration were explored, and some small–scale tests were<br />

carried out to demonstrate their capability to match the goals of the<br />

proposed experiment. As far as the safety issues are concerned, it is<br />

necessary to monitor the dust during the mobilization phase, then to<br />

trace the dust paths and to measure the dust velocities and<br />

concentrations during a simulated accident. The dust <strong>di</strong>agnostics so<br />

far adopted for dust detection inside the VV, during plasma burning,<br />

are not completely suitable for the safety purpose.<br />

A technique using a green laser to illuminate the particles, together<br />

with a fast camera charge–coupled device (CCD), was chosen,<br />

because it seemed to be the most promising one for the specific safety<br />

problem. The main purpose of the experiment was to measure<br />

particle concentrations by counting the number of particles inside a<br />

known volume and pre–set time intervals. The optical setup is then<br />

arranged in such a way to resolve in<strong>di</strong>vidual particles. Images are recorded on a video–camera, stored in<br />

picture formats and then analysed by an image processing procedure. A small scale test bench was set<br />

up (fig. 3.44).<br />

The proposed <strong>di</strong>agnostic system has the advantage to be flexible and adaptable to <strong>di</strong>fferent particle sizes and<br />

<strong>di</strong>fferent concentration con<strong>di</strong>tions.<br />

Limits on the maximum dust concentrations measurable are imposed by the laser extinction on the beam.<br />

Preliminary calculations and the experimental evidence lead to consider that densities higher by more than<br />

one order of magnitude than those obtained in the existing test (3.7×10 7 SS316 particles/m 3 , for example)<br />

would not limit the measurements. This will be one of the future scopes of the study. The type of dust is not<br />

<strong>di</strong>stinguished by the optical analysis proposed. A knowledge of the interactions among the <strong>di</strong>fferent types of<br />

dust during re-suspension for LOVA is complex and perhaps not feasible: the investigation of the <strong>di</strong>fferent<br />

particle velocities, depen<strong>di</strong>ng on the specific weight of the materials, could be a possibility.<br />

Validation of the PACTITER computer code and related fusion specific experiments in CORELE loop<br />

The objective of this work is the verification and validation of the PACTITER code v3.3, to be used for<br />

pre<strong>di</strong>cting activated corrosion products (ACPs) in ITER primary heat transfer system (PHTS) (EFDA Contract<br />

07–1702/1548 task TW6–TSS–SEA5.6). The second part of this activity has dealt with the application of<br />

PACTITER v3.3 to assess the ACP inventory of the ITER NBIs PHTS loop. The focus was given to the<br />

impact of operation scenarios parameters (i.e. water chemistry, materials corrosion properties, etc.) and loop’s<br />

piping architecture. The modelling of the NBIs PHTS loop has dealt with the description of the related<br />

geometric, thermo–fluido–dynamic, material features. The neutron activation of the NBIs (1 Diagnostic and<br />

2 Heating injectors) cooled regions was estimated in rough way as validated data were not available. The basic<br />

criteria used to set up the model are: the total coolant inventory, the wet surface and the mass flow rate of the


technology programme (cont’d.)<br />

progress report<br />

2010<br />

077<br />

PACTITER model are the same as the real ones; inlet<br />

coolant temperature of each injector component is 35°C.<br />

The NBIs PHTS ACP inventory calculations were carried<br />

out for a 7–week operation scenario split in 23 steps<br />

alternating the various operational phases gathered in<br />

table 3.I. Each operation day includes 14.4 h of mean up (or<br />

operation) time (MUT) and 9.6 h of not–scheduled mean<br />

down time (MDTNS). Every 11 operation days, 3 routine<br />

maintenance days (MDTs) are foreseen.<br />

The most important parameter governing the build–up of<br />

the ACPs inventory is the Cu and Cu alloy corrosion rate.<br />

The influence of chemical volume control system (CVCS)<br />

flow rate and filter efficiency is relatively scarce, as no<br />

appreciable reduction in the ACP mass was assessed by<br />

variation of those parameters. The possibility to separate the<br />

LV–active correction and compensation coils (ACCCs) from<br />

the NBIs PHTS by a de<strong>di</strong>cated cooling loop was also<br />

investigated. The impact of this choice would be remarkable<br />

in terms of ACP mass reduction (factor ∼3.7; see fig. 3.45,<br />

Run–8). That is explained by the large wet surface of<br />

ACCCs (3798 m 2 which is ∼50% of the total loop wet<br />

surface) made of Cu which is affected by a larger corrosion<br />

and release rates as compared to stainless steel regions.<br />

Another way to reduce the ACCCs wet surface of a factor 2<br />

is by doubling the pancake piping <strong>di</strong>ameter from 8 to<br />

16 mm. That would cause a drop of ∼40% of the ACP mass<br />

(see fig. 3.46, Run–5) [3.18].<br />

One might argue that splitting the NBIs PHTS loop in two<br />

parts would not reduce the overall ACP mass which would<br />

be transferred to the de<strong>di</strong>cated ACCCs cooling loop. The<br />

actual advantage is the reduction of ACPs ra<strong>di</strong>oactive<br />

inventory (see fig. 3.46). The larger ACP mass inventory of<br />

ACCCs would be contained in a de<strong>di</strong>cated loop, which will<br />

be much less activated, considering their position far from<br />

the plasma and from to the neutrons line of sight. On the<br />

contrary, if contained in the NBIs PHTS this large ACP<br />

inventory would be activated at higher level when<br />

transported to loop’s regions where the neutron flux is larger.<br />

Table 3.I – Main operation scenario data<br />

Operational<br />

phase<br />

Time<br />

(d)<br />

H 2<br />

(ppm)<br />

T mh<br />

*)<br />

(°C)<br />

Idle (MDT S ) 6.9 0.06 35<br />

Con<strong>di</strong>tioning<br />

(MDT S )<br />

3.6 2 55<br />

Injecting (MUT) 5.15 2 61<br />

Decay/dwell<br />

(MUT)<br />

Maintemance<br />

(MDT NS )<br />

18.0 0.06 45<br />

15.35 0.06 35<br />

*) T mh = means temperature of the primary fluid in the<br />

under flux region<br />

(g)<br />

8000<br />

4000<br />

0<br />

0<br />

Run-3 ACCCs wet surface=3798 m 2<br />

Run-5 ACCCs wet surface=1899 m 2<br />

Run-8 ACCCs wet surface=0 m 2<br />

20 40<br />

Time (days)<br />

Figure 3.45 – Impact of the ACCCs Ws on the ACP<br />

inventory (Run-3: full wet surface, Run–5: ½ wet<br />

surface, Run–8: no ACCCs)<br />

Surface activity (GBq)<br />

2000<br />

1000<br />

Run-3<br />

Run-8<br />

0<br />

0 20 40<br />

Time (days)<br />

Figure 3.46 – ACP surface activity in NBI–PHTS<br />

with ACCCs (Run–3) and without ACCCs (Run–8)<br />

Safety analyses by hazard and operability stu<strong>di</strong>es<br />

Several hazard and operability (HAZOP) stu<strong>di</strong>es have been performed for the ITER detritiation systems under<br />

the frame of <strong>di</strong>fferent ITER and F4E contracts/grant:<br />

• Pre–conceptual design of the high tritiated water processing system to detritiate highly tritiated water<br />

produced during normal and also abnormal situations of ITER operations (ITER<br />

Contract/CT/09/4300000087) [3.19].<br />

• Conceptual design of the tokamak complex detritiation system aimed at detritiating the gas effluents from<br />

tokamak complex (ITER Contract/CT/09/4300000098) [3.20].<br />

• Conceptual design of the water detritiation system aimed at storing and detritiating the aqueous effluents<br />

produced by the detritiation system and from other sources – F4E Grant –2010–GRT–045 (PNS–VPT)<br />

[3.21].<br />

The HAZOP stu<strong>di</strong>es have been performed accor<strong>di</strong>ng to the “ITER Guide to Performing Hazard and


078<br />

progress report<br />

2010<br />

Operability Stu<strong>di</strong>es”. After a first preliminary phase de<strong>di</strong>cated to developing the background information<br />

required for the analysis, such as to define the scope of the analysis, appoint a team leader with approval of<br />

ITER Responsible Officer, assemble the team to perform the HAZOP Study with approval of IO, collect<br />

relevant information and supporting documents, review the system and define the segments of the system to<br />

analyze and, review the ITER “Consequences of interest and hazards table”, team of experts performed the<br />

stu<strong>di</strong>es in de<strong>di</strong>cated meetings by applying the following procedure:<br />

• Review the segments of the system to be analyzed and the “Consequences of interest and hazards table” in<br />

order to get team consensus.<br />

• Select process variables (flow, pressure, etc.) and define operation modes to investigate.<br />

• For each segment, evaluate the potential consequence of the deviation of the process variables by applying<br />

guidewords.<br />

• Determine cause(s) lea<strong>di</strong>ng to deviation, and identify whether no cause can be determine or the con<strong>di</strong>tion<br />

of the cause.<br />

• Evaluate potential consequences and the correspon<strong>di</strong>ng hazards resulting from each deviation con<strong>di</strong>tion,<br />

and identify whether no consequence is identified or the consequence.<br />

• Develop detection and controls to mitigate effect of the deviation.<br />

• Determine the residual risk associated with the cause with the identified detections and controls, (e.g.:<br />

estimation of the likelihood of the cause occurring and the severity of the cause with the identified detection<br />

and controls).<br />

• Identify the correspon<strong>di</strong>ng residual risk (minimal, low, me<strong>di</strong>um or high) by using a risk matrix.<br />

• When the residual risk is high or me<strong>di</strong>um it will be noted as an action item to review whether ad<strong>di</strong>tional<br />

controls and detection are needed to mitigate the hazard.<br />

• Repeat procedure for each item: deviation of a process parameter (no, less, more, etc.) for the specific<br />

segment; for all process variables (flow, pressure, temperature, etc.) for the specific segment; for all segments<br />

in a section; for all sections in a system.<br />

• Document the identified detection and control for the system.<br />

• Assign responsible in<strong>di</strong>vidual and due date to address action items.<br />

• Integrate action items into detection and controls for system when complete.<br />

The HAZOP study has been concluded by the identification of limiting con<strong>di</strong>tions of operations (LCOs) for<br />

the overall events that might induce hazardous (incidental/accidental) con<strong>di</strong>tions. LCOs have been<br />

qualitatively identified in order to collect under common categories the detections and the controls most<br />

significant from the safety point of view.<br />

Most of the identified events inducing hazards for the environment and the workers have been classified with<br />

acceptable level of residual risk, as “No ad<strong>di</strong>tional detection and/or controls needed”, and “Detection and/or<br />

controls reasonable”. Only few events have been judged with a residual risk such to require “Review ad<strong>di</strong>tional<br />

detection and/or controls”. These events have been highlighted with an in<strong>di</strong>cation about consequences, in<br />

terms of the plant con<strong>di</strong>tions and hazards, and ad<strong>di</strong>tional detection and/or controls required.<br />

In this frame, <strong>ENEA</strong> developed a software tool to generate a HAZOP spreadsheet database, in agreement with<br />

the “ITER Guide to Performing Hazard and Operability Stu<strong>di</strong>es”.<br />

3.8 Broader Approach<br />

JT–60SA<br />

<strong>Layout</strong> study of JT–60SA coils power supplies and switching network units. Accor<strong>di</strong>ng to the Broader Approach<br />

(BA) program development, <strong>ENEA</strong> and Commissariat à l'Energie Atomique (CEA) had updated and reviewed<br />

the layouts of the new power supplies for JT–60SA PF coils, fast plasma position control coils, toroidal field<br />

(TF) coils and switch network units.<br />

JT–60SA will be located at JAEA NAKA Fusion Institute. Most of the existing buil<strong>di</strong>ng, infrastructure,<br />

available for the JT–60U devices, will be re–used for JT–60SA.


technology programme (cont’d.)<br />

progress report<br />

2010<br />

079<br />

The layout design of the power supplies and switch network units includes the installation of new PS and the<br />

re-use of the existing equipment and buil<strong>di</strong>ngs.<br />

Procurement of 4 switching network units for JT–60SA. In the frame of the BA agreement, Europe provides<br />

for the procurement of the central solenoid SNU of JT–60SA. The technical specifications for the call for<br />

tenders have been reviewed and mo<strong>di</strong>fied to include the project progress; the system simulation model has<br />

been integrated with thermal components in order to consider the heating/cooling behaviour of the static<br />

components.<br />

International Fusion Materials Irra<strong>di</strong>ation Facility<br />

The activities carried out in 2010 in the frame of the International Fusion Materials Irra<strong>di</strong>ation Facility<br />

(IFMIF) project are related to the following procurement arrangements.<br />

Participation to the experimental activity of the ELITE loop<br />

(Oarai, Japan) (LF 01 EU). The main components to be delivered<br />

to Japan have been designed and the order for the procurement<br />

of the instrumentation (Nano–ohmmeter, thermo–resistances,<br />

datalogger for thermo–resistances, and NIs items) for the<br />

R–meter, the E–Cubicle and the data acquistion systems (DACs)<br />

have been issued. The order for the mo<strong>di</strong>fication of the R–Meter<br />

instrument itself, capable of fulfilling the Japanese safety rules,<br />

was emitted as well.<br />

During the second half of 2010 the procedure to issue the<br />

contract for the final design and realization of the R–Meter box,<br />

support structure and the assembly of the electrical cabinet for<br />

the DACs of R–Meter and CASBA sensors was completed. In<br />

figure 3.47 two views of the final assembly of the R–Meter, of the<br />

magnet and of the heating system into the box are reported.<br />

Moreover, the new design of the removable backplate (BP) as well<br />

as the design of the frame were completed and their<br />

thermo–mechanical analysis started. As the design of the BP had<br />

been frozen, <strong>ENEA</strong> started the procedure for the procurement of<br />

EUROFER.<br />

Figure 3.47 – 3D model of R–meter, magnet,<br />

the heating system and the box<br />

In the figure 3.48 the 3D model of the removable BP is reported.<br />

Lithium erosion corrosion activity (LF03 EU). During the<br />

reporting period <strong>ENEA</strong> continued the commissioning of the<br />

lithium loop LiFus3. A new test section was also prepared as<br />

advised by the reviewer of the preliminary design review meeting.<br />

The charging and draining procedures were implemented and<br />

the performance of liquid level meters, thermocouples and<br />

pressure transmitters checked.<br />

Figure 3.48 – 3D model of the bayonet<br />

blackplate prototype<br />

During the month of November 2010 tests, the necessity to improve the control of the loop was underlined.<br />

Thus, several thermocouples were added both in the air cooler and in the gas lines and a new pressure<br />

transmitter was installed in the gas line over the test section. New Conax lithium level gauges have been<br />

ordered and the procurement of a new mass flow–meter has been decided.<br />

At the end of 2010 lithium circulation tests were performed and in December the lithium circulation by using<br />

a procedure <strong>di</strong>fferent from the standard one was obtained. Consequently, commissioning and testing of the<br />

loop was stopped due to <strong>di</strong>fferent technical and safety problems arisen during the lithium circulation tests. The<br />

outcomes of this test suggested that the loop should be updated and a number of interventions planned.<br />

Due to the limited time at the completion of the IFMIF project, a new test matrix was proposed and accepted<br />

by F4E and Project Team.


080<br />

progress report<br />

2010<br />

Figure 3.49 – Purification system of LiFus 3<br />

loop<br />

Figure 3.50 – Test rig after exposure<br />

Figure 3.51 – Stereoscopic image of the test rig SEM analysis of the gasket<br />

Implementation of the Li purification system (LF04 EU). LiFus 3 is provided a purification system consisting<br />

of a cold trap, a nitrogen hot trap and a hydrogen trap, designed by <strong>ENEA</strong> in collaboration with the University<br />

of Nottingham (fig. 3.49). This purification system has been updated in late 2009 to take into account the<br />

advices of an expert panel. The installation and commissioning of this system was completed early in 2010.<br />

Nevertheless, due to technical problems, still unsolved, of LiFus 3 loop the purification system has not been<br />

tested yet. Together with the purification system, an online monitoring system for the measurement of the<br />

nitrogen content in lithium was installed.<br />

Testing of the purification system is now planned in February 2011.<br />

Remote handling of the IFMIF target assembly system (LF 05 EU). During 2010, a series of technology and<br />

remote handling (RH) tasks were performed. The technology tasks were aimed at validating the current BP<br />

bayonet concept design. They included:<br />

1) The qualification of the lithium sealing capability of the Helicoflex gasket (see fig. 3.50). This experimental work was<br />

addressed at evaluating the compatibility with lithium of the outer Jacket material of the gasket (i.e. Soft<br />

Iron). After 1800 hrs of exposure at 350°C, post analyses of the rigs, stereoscopic and scanning electron<br />

microscopy (SEM) analyses (see fig. 3.51), were performed. The main outcomes of the tests highlighted the<br />

suitability of the proposed sealing system. Further tests are planned in 2011, thus exten<strong>di</strong>ng the exposure<br />

time up to 6000 hrs.<br />

2) Evaluation of the swelling phenomena and its impact on the BP coupling system (University of Palermo). This activity was<br />

aimed at evaluating the thermo–mechanical issues potentially induced by neutron swelling in the threaded<br />

connections of the IFMIF target BP. A parametric analysis was carried out for each kind of bolt by<br />

considering a swelling volumetric strain ranging from 0.001% to 0.1%, and both the maximum equivalent<br />

stress within the screw (see fig. 3.52) and the unscrewing torque (see fig. 3.53) were estimated. The results<br />

obtained highlighted that screw <strong>di</strong>mensions seem to influence mainly the highest values of the unscrewing<br />

torque which are reached at ε sw<br />

∼0.04÷0.05%, regardless of the screw <strong>di</strong>ameter. The maximum ε sw


technology programme (cont’d.)<br />

progress report<br />

2010<br />

081<br />

acceptable to avoid unscrewing torque to be higher than<br />

80 Nm has been assessed for the bolts considered.<br />

Further analyses will be carried out in 2011 to investigate the<br />

potential influence of the screw length of engagement on the<br />

bolt connection thermo–mechanical performances, in<br />

presence of neutron swelling.<br />

3) Bolting seizure and the pre–stress tests. This activity is addressed to<br />

select suitable materials for bolts with the objective to prevent<br />

their seizure or relaxation. The first test was performed early<br />

in 2010, by using the test section shown in figure 3.54, and due<br />

to the bad results (all the bolts broke after an exposure of 1000<br />

hrs at 350°C) the experiment will be repeated in 2011.<br />

4) Validation of the skate system concept. This task is focused at<br />

evaluating the performance and the reliability of the skate<br />

system. In 2010 the following activities were performed:<br />

• Control and DAQ systems design was completed;<br />

• A set of sensors (extensometers) to perform a preliminary<br />

test on the BP already available in DRP were purchased<br />

and delivered.<br />

The setting up of the experiment will start early in 2011.<br />

The RH tasks were focussed on the validation of the cleaning<br />

procedure for the removal of sticked lithium metal from steel. In<br />

detail:<br />

• Cleaning procedure. In order to clean up steel specimens from<br />

sticked liquid metals, at <strong>ENEA</strong> Brasimone a mixed low aci<strong>di</strong>c<br />

solution was developed. It consists of: acetic acid [1N]<br />

(CH 3<br />

COOH)+hydrogen peroxide (H 2<br />

O 2<br />

)+Ethanol<br />

(CH 3<br />

CH 2<br />

OH) with the same ratio (1:1:1).<br />

This cleaning solution has been used at room temperature, for<br />

cleaning Li, PbLi, Pb, LBE and, accor<strong>di</strong>ng to weight<br />

measurements and electronic microscopy, no steels' kind<br />

(ferritic or martensitic or austenitic) have ever been attacked or<br />

mo<strong>di</strong>fied or corroded due to the treatment.<br />

This cleaning solution can be used both by immersion or<br />

spraying over a <strong>di</strong>rty surface.<br />

• RH test of the cleaning procedure. To test the feasibility of the<br />

cleaning operations a very simple tool (see fig. 3.55) was<br />

manufactured and some trials were performed. Tests were<br />

performed by using a prototype of the backplate frame and a<br />

simulation of the TMs (a simple steel plate). The space<br />

available to perform the operation was of about 5 cm, which<br />

is the space left by the high flux test module (HFTM) once<br />

removed.<br />

Engineering design of the IFMIF target assembly system (ED 03).<br />

The technical work performed in the reporting period was<br />

de<strong>di</strong>cated to: 1) starting the design of the target assembly with<br />

bayonet BP for IFMIF; 2) making a preliminary neutronic<br />

calculation of the newly designed BP.<br />

1) Design of the IFMIF target assembly. A preliminary 3D CATIA<br />

model of the BP component – inclu<strong>di</strong>ng the lateral skate<br />

systems and the double reducer nozze – has been<br />

accomplished (fig. 3.56). Starting from the Engineering<br />

Validations and Environmental Engineering Design Activities<br />

εsw=0.1%<br />

Figure 3.52 – Von Mises stress <strong>di</strong>stribution at<br />

<strong>di</strong>fferent swelling strain<br />

T(Nm)<br />

1200<br />

800<br />

400<br />

0<br />

0.0<br />

M10<br />

M12<br />

M16<br />

0.04 0.08<br />

ε sw (%)<br />

Figure 3.53 – Unscrewing torque vs swelling<br />

volumetric strain<br />

F82H<br />

F82H<br />

EUROFER<br />

Inconel<br />

Figure 3.54 – Test rig for the bolted coupling<br />

system<br />

Figure 3.55 – Cleaning tool<br />

Figure 3.56 – Front view a) and rear view b)<br />

ofthe newly designed IFMIF target


082<br />

progress report<br />

2010<br />

BP<br />

Lithium JET<br />

Atom <strong>di</strong>splacement, dpa/fpy 4.7–10 –1<br />

He production, apppm/fpy 2<br />

H production, apppm/fpy 9<br />

Total heating W/cm 3 3.8–10 –1<br />

HFTM<br />

Atom <strong>di</strong>splacement, dpa/fpy 54<br />

He production, apppm/fpy 598<br />

H production, apppm/fpy 2742<br />

Total heating W/cm 3 23.08<br />

Figure 3.57 – BP<br />

geometrical layout of<br />

MCNP5 code<br />

Figure 3.58 – Main of the<br />

outcomes of the neutronic<br />

calculations on the BP<br />

superimposed mesh tally<br />

(EVEDA) lithium loop concept, the new design has been generated by enlarging the width of the lithium<br />

flow channel from the 100 mm of the EVEDA loop target to the actual IFMIF <strong>di</strong>mensions (260 mm) and<br />

mo<strong>di</strong>fying all other <strong>di</strong>mensions accor<strong>di</strong>ngly in order to fit the new channel size. The channel profile that has<br />

been implemented is the variable–curvature profile (with no straight sections) formerly designed by <strong>ENEA</strong>.<br />

As to the EVEDA design, the channel profile has now been entirely placed on the BP instead of <strong>di</strong>stributing<br />

it in between the BP and the interface frame. This solution is aimed at eliminating manufacturing problems<br />

and alignment issues between the two components.<br />

A first design optimization has been reached by eliminating all the unnecessary material in order to reduce<br />

the weight as much as possible. This preliminary design has been assessed from the neutronic point of view.<br />

Next step will be a thermo-mechanical assessment in order to evaluate the stress field in the componente,<br />

thus optimizing the design features on this basis.<br />

2) Neutronic calculations. In order to quantify the material damage due to neutron irra<strong>di</strong>ation the following was<br />

determined:<br />

a) Heat deposition due to neutron and gamma interactions with nuclides.<br />

b) Ra<strong>di</strong>ation damage (quantified by the number of dpa.<br />

c) Gas production, e.g. total production of helium and hydrogen produced by neutron induced<br />

nuclearreactions.<br />

Preliminary neutron/gamma transport calculations have been performed for the BP via MCNP5 code,<br />

version 1.4 (fig. 3.57).<br />

The neutron induced cross section data files used in the calculations have been taken mainly from INPE–50<br />

library, developed at INPE–Karlsruhe Institute of Technology (KIT), for neutron energies up to 50 MeV,<br />

and LANL–150N, developed at Los Alamos National Laboratory, for neutron energies up to 150 MeV.<br />

The BP profile was approximated in MCNP5 code through a combination of cylinders parallel to X<br />

(horizontal) axis. Mapping on the BP through “superimposed mesh tally” feature of MCNP5 has been used<br />

(fig. 3.58).<br />

DEMO R&D in the Broader Approach activities<br />

Development of CiC composite materials (task T1–2–5). In the framework of the Broader Approach activities<br />

for the development of composite SiC materials, <strong>ENEA</strong> laboratories have completed the experimental plan<br />

and the preliminary design of the test apparatus aimed at studying the erosion/corrosion of SiC composites<br />

into PbLi.


technology programme (cont’d.)<br />

progress report<br />

2010<br />

083<br />

In particular, the manufacturing of the experimental apparatus consisting of a high temperature oven has<br />

been continued accor<strong>di</strong>ng to an updated mechanical design which will permit operating up to 1200 °C with<br />

a SiC/PbLi relative velocity of 1 m/s.<br />

3.9 JET Fusion Technology<br />

JET housekeeping wastes detritiating<br />

A Pd–based membrane reactor for detritiating JET housekeeping wastes has been stu<strong>di</strong>ed (JET task<br />

JW10–FT–2.35) [3.22]. A finite element computer code permitted to simulate the behavior of the membrane<br />

reactor by varying the main operating parameters [3.23,3.24]. The increase in the temperature affects very<br />

slightly the detritiation capability while a reduction of the membrane thickness increases the decontamination<br />

factor. On the basis of the reactor modeling, the design and the manufacturing of a Pd–Ag permeator tube<br />

of <strong>di</strong>ameter 10 mm, length 500 mm and wall thickness 0.150, has been carried out. Further, the design of the<br />

membrane reactor has introduced an innovative module configuration [3.25], see figures 3.59 and 3.60. This<br />

innovative design mainly consists of a special device applied to the closed end of the permeator tube. It is a<br />

metallic spring coupled with a flexible wire with two functions:<br />

• to apply a traction force to the permeator tube in order to avoid its contact with the inner walls of the<br />

membrane module and to prevent deformations due to thermal and hydrogenation cycles,<br />

• to ensure the electrical continuity between the closed end of the permeator tube and the outside of the<br />

membrane module by allowing the heating of the tube via Joule effect.<br />

In the reactor manufactured by <strong>ENEA</strong>, this component is composed by:<br />

• an Inconel spring, able to guarantee the required mechanical performances at the working temperature<br />

(300–400°C) and apply to the permeator tube a traction force sufficient to drive it along a straight <strong>di</strong>rection<br />

during its thermal/hydrogenation expansion,<br />

• a copper wire, to ensure the electric current passage with a low electrical resistance.<br />

Direct ohmic heating has the advantage to heat the membrane only, thus reducing the heating of the process<br />

streams and saving power [3.26]. Furthermore, the traction force applied by the Inconel spring prevents<br />

ben<strong>di</strong>ng of the long (500 mm) Pd–Ag tube, thus ensuring long life to the membrane.<br />

He<br />

H 2 O<br />

HTO<br />

H<br />

He<br />

H 2 O<br />

Pd-Ag membrane tube<br />

H 2<br />

HTO<br />

2<br />

HT<br />

HT H 2 H 2 HT H 2<br />

HT H 2 HT H 2<br />

Bi-metallic<br />

spring<br />

Insulating electric<br />

feedthrough<br />

H 2<br />

HT<br />

Catalyst<br />

Power<br />

supply<br />

Figure 3.59 – Scheme of the Pd–based membrane reactor for the JET housekeeping wastes detritiation<br />

Figure 3.60 – Pd–based membrane reactor before assembling


084<br />

progress report<br />

2010<br />

Arb. units<br />

Counts/s<br />

10 13<br />

10 11<br />

10 9<br />

0<br />

10 4<br />

10 2<br />

10 0<br />

γ rays (NE213) 33519<br />

33516<br />

33517<br />

33520<br />

33522<br />

33512<br />

33661<br />

a)<br />

Time (s)<br />

γ rays (GEM)<br />

0 1<br />

Time (s)<br />

Figure 361 – Comparison of gamma-ray<br />

signals in FTU plasma <strong>di</strong>scharges: a) time<br />

traces from a NE213 detector; b) time<br />

traces from GEM pad #1<br />

a)<br />

1<br />

33519<br />

33516<br />

33517<br />

33520<br />

33522<br />

33512<br />

33661<br />

b)<br />

-33012<br />

-2577<br />

GEM–based neutron detector for 2.5 and 14 MeV<br />

The development of a gas electron multiplier (GEM)–based<br />

neutron detector for simultaneous 2.5 MeV (DD) and 14 MeV (DT)<br />

measurements has continued in the frame of an EFDA task on<br />

Diagnostics (WP10–DIA–04–01–xx–02). The detector, consisting<br />

of a proton recoil neutron converter and a triple GEM structure<br />

based on a Ar/CO 2<br />

/CF 4<br />

– 45/15/40 gas mixture, is <strong>di</strong>vided in two<br />

sub–units (U DT<br />

and U DD<br />

) respectively measuring 14 MeV neutrons<br />

only and 2.5 + 14 MeV neutrons [3.27]; the U DT<br />

sub–unit is<br />

provided with an aluminum layer (200 μm thick) for the rejection of<br />

protons produced by 2.5 MeV neutrons. The detector has been<br />

installed just outside the cryostat of the Frascati Tokamak Upgrade<br />

(FTU) device on the equatorial plane between ports 11 and 12.<br />

Preliminary acquisitions have been performed during plasma<br />

<strong>di</strong>scharges in the 2010 experimental campaign. Unfortunately, as<br />

hydrogen gas (instead of deuterium) was used in these <strong>di</strong>scharges<br />

due operational constraints, it has been possible to study just the<br />

response of the detector to gamma rays produced by runaway<br />

electrons. Note that this detector is also sensitive to gamma rays<br />

when a high high voltage (HV) setting is used. Results for seven<br />

<strong>di</strong>scharges are shown in figure 3.61 (HV=1180 V): in all cases the<br />

GEM signals correctly reproduce the time behaviour and relative<br />

intensity of the gamma signals from the reference gamma-ray<br />

scintillator detector.<br />

Further tests with the GEM neutron detector have been carried out<br />

by using a 241 AmBe neutron source in the frame of an EFDA Joint<br />

European Torus (JET) Fusion Technology task (JW9–FTFT–5.31).<br />

The source (sketched in figure 3.62 as a cylinder) has been placed<br />

<strong>di</strong>agonally at about 2 cm from the detector. Results are shown in<br />

figure 3.62. At high HV both neutrons and gamma–rays are<br />

detected by the two sub-units units. At lower HV the detected signal<br />

is due to neutrons only and is mainly seen by the U DD<br />

sub–unit as<br />

the aluminum layer in the U DT<br />

cuts the signal due to neutrons with<br />

E


technology programme (cont’d.)<br />

progress report<br />

2010<br />

085<br />

Counts<br />

10000<br />

100<br />

14 MeV neutrons<br />

Q S /Q L<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

γ<br />

14 MeV n from dt<br />

2.5 MeV n from dd<br />

300<br />

200<br />

100<br />

0 0<br />

0 400 800 1200 1600 2000<br />

1<br />

0 1000<br />

Channels<br />

2000<br />

Figure 3.63 – Example of 14 MeV<br />

monoenergetic neutron beam measurement<br />

during the CNS detector characterization<br />

campaign at PTB<br />

Q T /Arb. units<br />

Figure 3.64 – CNS capability of n/γ <strong>di</strong>scrimination and<br />

simultaneous 2.5 MeV and 14 MeV neutron<br />

measurements: 98% of the recorded pulses represent<br />

good data (2% of bad reconstructed pulses have now<br />

been fixed using the last release of the pre-processing<br />

routine)<br />

characterization matrix is on–going. Moreover, data collected in the previous JET experimental campaign<br />

have been analyzed in order to study the system’s performance during plasma <strong>di</strong>scharges (see fig. 3.64): some<br />

minor bugs in the data pre–processing routine have been found and fixed. The final installation and<br />

commissioning at JET of the CNS <strong>di</strong>agnostic is foreseen in 2011–2012.<br />

3.10 Cryogenics<br />

Liquid helium service<br />

The temperature of liquid helium at normal boiling point is 4.2 K (about –296°C). It is therefore used as a<br />

typical refrigerant for cooling of experimental equipments at very low temperatures. Helium, however, is<br />

rather expensive, so that recovering the helium evaporated during experiments may be beneficial, provided<br />

that the overall helium consumption is large enough. The gas recovered and compressed in a suitable storage<br />

system can indeed be liquefied again, subject to prior purification, thus allowing recycling the same amount<br />

of helium many times.<br />

A number of activities pursued by the Fusion Technical Unit at the Frascati Research Centre of <strong>ENEA</strong> require<br />

considerable amounts of liquid helium every year. The experiments with the FTU need liquid helium to cool<br />

down the magnets of the auxiliary heating facility electron cyclotron resonance heating (ECRH), or to freeze<br />

solid deuterium pellets to be injected at high speeds into the fusion plasma, as well as to keep plasma<br />

<strong>di</strong>agnostics at low temperature. The Superconductivity laboratory also uses sizeable amounts of liquid helium<br />

for experiments with large superconducting magnets, as well as to test critical components at low temperatures.<br />

A helium recovery facility and a helium liquefier are therefore operating in the Centre, which allows helium<br />

to be recycled many times, thus saving a considerable amount of money. The helium liquefier is a Linde<br />

TCF20, featuring a cold box equipped with an internal auto–purifier and two turbine expanders for gas<br />

pre–cooling, a screw driven DS220 recycling compressor equipped with an oil removal system, a line drier, a<br />

pressure control panel, two self–pressurizing dewars (1.000 l each) for liquid helium storage, two transfer and<br />

decant lines, a 7 m 3 pure helium buffer tank and an analytical panel equipped with a purity monitor and a<br />

moisture meter. An Allen Bradley Programmable Logic Controller automatically controls the plant, which was<br />

supplied by Linde Cryogenics Ltd. (UK) on April 1999. The nominal liquid helium production rates, with or<br />

without liquid nitrogen precooling, are of 60 and 30 l/h.<br />

In 2010, nearly 14.300 litres of liquid helium have been delivered to the users, which is slightly less than the<br />

amount of the previous year (about 19.500 litres). About 20% of the liquid evaporates (to the recovery system)<br />

while decanting it from the storage vessel to transport dewars (in order to deliver the product to the users).<br />

Moreover, the self–pressurizing storage dewar features an evaporation rate of about 25 liter/day, due to the<br />

unavoidable heat losses; of course, the helium vaporized from the liquid storage is recovered too. As a<br />

consequence, the overall liquid helium inventory managed in 2010 turns out to be roughly 23.200 litres. Nearly


086<br />

progress report<br />

2010<br />

12.500 litres (correspon<strong>di</strong>ng to more than 230 hours of operation) have been produced by the Linde liquefier,<br />

while the remaining 10.700 litres have been purchased to compensate for the system losses. The resulting<br />

average recovery efficiency is estimated to be about 53.8%, less than that recorded in 2009 (when about 65.5%<br />

was recovered). Such a low recovery efficiency is partially due to some deman<strong>di</strong>ng experiments carried out by<br />

the Superconductivity laboratory, which may occasionally require considerable amounts of refrigerant to be<br />

evaporated in a very short time, thus making both the capacity of the gas bag (5 m 3 ) and the throughput of<br />

the recovery compressors (80 m 3 /hr), inadequate. Moreover, during about six months of 2010, the recovery<br />

system was operating with only one of its two compressors, due to maintenance being performed in turn on<br />

both machines, as it is necessary after 15.000 hours of operation. This resulted in a reduced recovery<br />

throughput of only 40 m 3 /h and therefore in losses larger than usual.<br />

Data from independent gas counters in the (separated) recovery lines of each user allowed, throughout 2010,<br />

the <strong>di</strong>fferent recovery efficiencies to be <strong>di</strong>sentangled by FTU and Superconductivity laboratory. As a matter of<br />

fact, by comparing the amounts of liquid helium delivered and of gas recovered by Superconductivity<br />

laboratories and FTU it is possible to evaluate the percentage of total helium lost by each user.<br />

References<br />

[3.1] G. Ramogida et al., Final report on the analysis of the ITER <strong>di</strong>vertor cassettes, Contract EFDA/07/1702–1596<br />

(TW6–TVD–DIAGAN), <strong>ENEA</strong> Internal Report FUS–TN–DI–R–009/Rev.1, (October 2010)<br />

[3.2] G. Ramogida et al., Final report on the preliminary electro–magnetic load analysis for the design of a blanket<br />

manifold pipe concept for ITER, Contract EFDA/07/1702–1620 (TW6–TVB–MANEM), <strong>ENEA</strong> Internal Report FUS–<br />

TN–BB–R–034/Rev.1, (December 2010)<br />

[3.3] S. Tosti et al., Conceptual PFD of HTW processing, KIT Report TLK–CEW–0990PMT1–RD–0D02–01, 5 (May 2010)<br />

[3.4] C. Rizzello et al., Fusion Eng. Des. 85, 58–63 (2010)<br />

[3.5] M. D’Arienzo et al., Fusion Eng. Des. 85, 2288–2291 (2010)<br />

[3.6] F. Borgognoni et al., Fusion Eng. Des. 85, 2171–2175 (2010)<br />

[3.7] A. Santucci et al., A comparison study of highly tritiated water decomposition processes, Presented at the 9th<br />

International Conference on Tritium Science and Technology – Tritium (Nara, Japan 2010)<br />

[3.8] P. Rossi et al., Ultimate tensile strength testing campaign on ITER pre–compression ring mock–ups, Presented<br />

at the 26th Symposium on Fusion Technology – SOFT (Porto 2010) and to appear in Fusion Eng. Des.<br />

[3.9] F. Crescenzi et al., Mechanical characterization of glass fibre–epoxy composite material for ITER<br />

pre–compression rings, Presented at the 26th Symposium on Fusion Technology – SOFT (Porto 2010) and to<br />

appear in Fusion Eng. Des.<br />

[3.10] L. Petrizzi, F. Moro, Final report on ITER <strong>di</strong>agnostic port integration: <strong>di</strong>agnostic port plug engineering and<br />

integration, <strong>ENEA</strong> Internal Report FUS TN GE–VD–Q–001, Contract: FU06 CT 2006–00134 (EFDA/06–1432),<br />

(February 2010)<br />

[3.11] F. Moro et al., Neutronic calculations in support of the design of the ITER high resolution neutron spectrometer,<br />

Presented at the 26th Symposium on Fusion Technology – SOFT (Porto 2010) and to appear in Fusion Eng.<br />

Des.<br />

[3.12] R. Villari, L. Petrizzi, G. Brolatti, Three–<strong>di</strong>mensional neutronic analysis of the ITER in–vessel coils, Final Report<br />

of the Contract ITER/CT/09/4100001120, deliverable D2-2 (November 2010)<br />

[3.13] R. Villari et al., Three–<strong>di</strong>mensional neutronic analysis of the ITER in–vessel coils, Presented at the 26th<br />

Symposium on Fusion Technology – SOFT (Porto 2010) and to appear in Fusion Eng. Des.<br />

[3.14] R. Villari, L. Petrizzi, Neutron and gamma spectra behind ITER blanket modules and in <strong>di</strong>vertor, Final Report of<br />

the Contract ITER/CT/09/4100001120, deliverable D1–1 (March 2010)<br />

[3.15] R. Villari, L. Petrizzi, Neutronic analysis of ITER <strong>di</strong>vertor rails, Final Report of the Contract<br />

ITER/CT/09/4100001120, deliverable D2–1 (April 2010)<br />

[3.16] D. Marocco, B. Esposito, F. Moro, Combined unfol<strong>di</strong>ng and spatial inversion of neutron camera measurements<br />

for ion temperature profile determination in ITER, to appear in Nucl. Fusion<br />

[3.17] V. Cocilovo, M.T. Porfiri, R. De Angelis, A channel facility for ITER safety relevant dust mobilization stu<strong>di</strong>es,<br />

Presented at the 19th Topical Meeting on the Technology of Fusion Energy – TOFE (Las Vegas 2010)<br />

[3.18] L. Di Pace et al., Application of PACTITER v3.3 to the ACPs assessment of ITER neutral beam injectors primary<br />

heat transfer system, Presented at the 19th Topical Meeting on the Technology of Fusion Energy, – TOFE (Las<br />

Vegas 2010)


technology programme (cont’d.)<br />

progress report<br />

2010<br />

087<br />

[3.19] T. Pinna et al., HAZOP study for the HTW processing, <strong>ENEA</strong> Internal Report FUS–TN–SA–SE–R–208 (June 2010)<br />

[3.20] T. Pinna, C. Rizzello, A. Santucci, HAZOP study for the TC–DS conceptual design, <strong>ENEA</strong> Internal Report<br />

FUS–TN–SA–SE–R–209 (August 2010)<br />

[3.21] T. Pinna, C. Rizzello, A. Santucci, HAZOP study for the preliminary conceptual design of water detritiation<br />

system, <strong>ENEA</strong> Internal Report FUS–TN–SA–SE–R–214 (2010)<br />

[3.22] S. Tosti et al., Processo per la detriziazione <strong>di</strong> soft housekeeping waste e impianto relativo, Domanda <strong>di</strong> brevetto<br />

per invenzione industriale n. RM2010A000340 del 22.06.2010<br />

[3.23] F. Borgognoni et al., Multi physic approach for Pd–based membrane reactor modeling for wet gas detritiation,<br />

Presented at the 9th International Conference on Tritium Science and Technology – Tritium (Nara, Japan 2010)<br />

[3.24] S. Tosti et al., Design of Pd–based membrane reactor for gas detritiation, to appear in Fusion Eng. Des.<br />

10.1016/j.fusengdes.2010.11.021<br />

[3.25] S. Tosti et al., Reattore a membrana per il trattamento <strong>di</strong> gas contenti trizio, Domanda <strong>di</strong> brevetto per<br />

invenzione industriale n. RM2010A000330 del 16.06.2010<br />

[3.26] S. Tosti, F. Borgognoni, A. Santucci, Electrical resistivity, strain and permeability of Pd–Ag membrane tubes, Int.<br />

J. Hydrogen Energy 35, 7796–7802 (2010)<br />

[3.27] B. Esposito et al., Nucl. Instrum. Meth. A 617, 155–157 (2010)<br />

[3.28] F. Belli et al., Conceptual design, development and preliminary tests of a compact neutron spectrometer for<br />

the JET experiment, Procee<strong>di</strong>ng of the IEEE Nuclear Science Symposium Conference, Record, N13–170 (2009)


088<br />

progress report<br />

2010<br />

chapter 4<br />

superconductivity<br />

During 2010 the Superconductivity laboratory activities regarded manufacturing and testing of conductor<br />

samples for ITER (the way in latin) and its satellite facilities, in ad<strong>di</strong>tion to characterization and research on<br />

conventional low–temperature superconducting (LTS) materials and high temperature superconductor (HTS)<br />

coated conductors.<br />

Concerning the cable–in–conduit conductor (CICC) production, <strong>ENEA</strong> was involved in manufacturing the<br />

two poloidal field (PF) conductor samples PF1 and PF2 for ITER, and in the compaction of ITER centrals<br />

solenoid (CS) empty tubes. Activities were also carried out for the feasibility verification of the superconducting<br />

toroidal field (TF) magnet system of the Fusion Advanced Stu<strong>di</strong>es Torus (FAST). Besides these activities,<br />

<strong>ENEA</strong> was involved in the heat exchanger design for the 30 kA current leads of <strong>ENEA</strong> CICC upgrade facility<br />

and in the study on the effect of strand ben<strong>di</strong>ng on the voltage-current characteristic of Nb 3<br />

Sn CICCs.<br />

R&D on LTS was devoted to transport and structural stu<strong>di</strong>es on NbTi and Nb 3<br />

Sn strands. Direct inter–<br />

filament resistivity measurements were extended from Nb 3<br />

Sn to NbTi samples; with the aim to clarify how<br />

the jacket affects the strain configuration in the complex system of multi–filamentary strands, <strong>ENEA</strong> carried<br />

out high–resolution x–ray <strong>di</strong>ffraction measurements at the high–energy scattering beam–line ID15B of the<br />

European Synchrotron Ra<strong>di</strong>ation Facility (ESRF) in Grenoble. The <strong>ENEA</strong> 2–components pinning model for<br />

NbTi has been updated in order to take into account the temperature non–scaling. Several commercial Nb 3<br />

Sn<br />

and NbTi samples have been characterized by means of inductive and transport measurements in the <strong>ENEA</strong><br />

superconductivity facilities.


superconductivity (cont’d.)<br />

progress report<br />

2010<br />

089<br />

4.1 Cable–in–Conduit Conductor<br />

Manufacturing of ITER poloidal field conductor samples<br />

<strong>ENEA</strong> is involved in the ITER program for the final qualification<br />

of the conductors before the production phase. In this framework<br />

<strong>ENEA</strong> was awarded two contracts, one from Iter Organization<br />

(IO) and one from Fusion for Energy (F4E), for the manufacturing<br />

of two PF conductor samples (PF1 and PF2,<br />

ITER/CT/09/4300000048 Support on ITER PF conductor<br />

sample design and preparation; F4E–2009–OPE–021 (MS–MG)<br />

PF conductor sample). The activities started at the end of 2009<br />

and went on for the first months of 2010, and have been split<br />

between <strong>ENEA</strong> and Commissariat à l’Energie Atomique (CEA)<br />

laboratories.<br />

In particular, <strong>ENEA</strong> took care of jacketing and compacting the<br />

cables supplied by IO and F4E (PF1 cable manufactured by the<br />

Russian Domestic Agency and PF2 by Chinese Domestic Agency),<br />

of preparing the cables and designing, manufacturing and<br />

assembling the hairpin boxes. The hairpin box solution (fig. 4.1),<br />

an <strong>ENEA</strong> concept which avoids the use of a resistive joint between<br />

the two conductors, should <strong>di</strong>minish the possibility of current<br />

re<strong>di</strong>stribution effects close to the high field sample zone. CEA<br />

prepared the upper terminations, assembled at <strong>ENEA</strong><br />

laboratories, and performed the sample insulation (fig. 4.2) and<br />

instrumentation at CEA laboratories. As a result of these<br />

contracts’ activities, two samples have been delivered to Centre de<br />

Recherches en Physique des Plasmas (CRPP) and successfully<br />

tested there in the SULTAN facility.<br />

Figure 4.1 – Hairpin box<br />

Figure 4.2 – PF sample, clamping and<br />

insulation<br />

Compaction of ITER CS empty tubes<br />

To the purpose of obtaining a relevant stress–strain state to<br />

perform ben<strong>di</strong>ng trials in preparation of the win<strong>di</strong>ng operations,<br />

IO placed a contract to <strong>ENEA</strong> to compact 10 empty tubes of<br />

316LN steel. In this framework, <strong>ENEA</strong> took care of all the<br />

relevant activities concerned with the compaction (fig. 4.3). In<br />

particular, a deep inspection of the tubes external surface has been<br />

performed together with a comprehensive <strong>di</strong>mensional survey of<br />

Figure 4.3 – ITER CS during compaction


090<br />

progress report<br />

2010<br />

each tube as to: i) total length; ii) wall thicknesses at head, middle and tail positions; iii) external width and<br />

height at head, middle and tail positions; iv) inner <strong>di</strong>ameter at head, middle and tail positions.<br />

Once the compaction was completed, a verification of the final <strong>di</strong>mensions was conducted, thus establishing<br />

the opportunity of estimating the thickness change and the elongation due to the compaction.<br />

Feasibility verification of the superconducting proposal of the TF magnet system of FAST<br />

FAST, the Italian proposal of a satellite facility to ITER, has been the object of an intense activity aimed at<br />

investigating the feasibility of a superconducting solution for its magnet system. In particular, an analysis of<br />

the TF magnets thermal behaviour has been carried out. The minimum temperature margin in the coil has<br />

been calculated for the thermal load <strong>di</strong>stribution on win<strong>di</strong>ng and cable jacket due to nuclear heating.<br />

Moreover, only the room available in the resistive design has been considered and reference has been made to<br />

one of the most severe scenarios envisaged for FAST. Indeed, one of the main critical aspects in the operation<br />

of a superconducting TF magnet is the conductor heating due to <strong>di</strong>rect energy deposition by neutrons and by<br />

secondary gamma rays generated during plasma operation. The operating temperature and the relevant<br />

temperature margin (i.e. the operating safety margin) of the magnet depend both on the heat loads and on the<br />

capability of the coolant to remove it. In this framework, some analyses have been performed aimed at<br />

verifying the vali<strong>di</strong>ty of the assumptions based, where possible, on the design parameters of similar machines.<br />

Finally, the need for a neutron shield has been preliminarily assessed by comparing the effect of <strong>di</strong>fferent<br />

nuclear heating thermal loads on the performance of the SC cable.<br />

Heat exchanger design for the 30 kA current leads of <strong>ENEA</strong> CICC upgrade facility<br />

<strong>ENEA</strong> is carrying out an upgrade of the existing CICC facility for the characterization of superconducting<br />

long length wound conductors in forced He flow cooling. In this framework, a considerable effort has been<br />

spent for the design of a pair of optimized gas–cooled current leads for a 30 kA insert. Indeed, several<br />

geometrical and operational constraints have been considered due to the re–use of the pre–existing cryogenic<br />

plant and background magnet. In particular, to limit the overall length of the leads and the amount of cooling<br />

gas to be employed, a hybrid resistive/HTS configuration has been adopted. It consists of a copper bar, with<br />

an adequate heat exchanger, from room temperature down to 40 K and an HTS part made of BSCCO from<br />

40 K down to 5 K. Two helium inlets are foreseen for the lead<br />

cooling: one at 5 K at the bottom edge, in parallel to the<br />

background magnet refrigerant line, and one at 16 K in the<br />

joint between the resistive and the HTS parts. To avoid the<br />

formation of short paths, typical of the braided solution<br />

adopted in the leads installed in the <strong>ENEA</strong> facility, a helical<br />

configuration of the heat exchanger around the current<br />

carrying copper bar has been conceived. Moreover, a reduction<br />

Figure 4.4 – Temperature <strong>di</strong>stribution in the<br />

3D CFD analysis carried out in the exchanger<br />

design<br />

in the manufacture cost is expected as compared to other<br />

solutions that rely on finned bars or zig–zag approaches.<br />

Calculated temperature <strong>di</strong>stribution is shown in figure 4.4.<br />

Study on the effect of strand ben<strong>di</strong>ng on the voltage–current characteristic of Nb 3<br />

Sn CICC<br />

The primary issue of Nb 3<br />

Sn CICCs has been degradation, often observed during electromagnetic cycling, in<br />

the current sharing temperature, n–index, and critical current, as to measured strands values, due to strain<br />

effects. In the last years, work performed mostly relating to fusion magnet technology has led to a better<br />

understan<strong>di</strong>ng of the parameters required to improve the constraints imposed by the brittle nature of the<br />

Nb 3<br />

Sn filaments, such as cables low void fraction and long twist pitch sequence. On the other hand,<br />

experimental campaigns on bent Nb 3<br />

Sn wires, pre-compressed into a stainless–steel jacket, have shown that<br />

an appreciable decrease in the n–index values already occurs at the strand level, well below the irreversible<br />

mechanical load regime for filament breakage.<br />

This result is explained, with the support of simulation results, by taking into account the broadening of the<br />

critical current <strong>di</strong>stribution on the wires’ cross section due to the presence of the jacket and to ben<strong>di</strong>ng strain.<br />

Considering the impact of the CICCs’ layout on their overall performances, the effective resemblance between


superconductivity (cont’d.)<br />

progress report<br />

2010<br />

091<br />

pre–compressed bent wires and strands inside cables is emphasized, and an innovative interpretation of the<br />

cabled conductors test results is given, from which a tool can be derived to pre<strong>di</strong>ct their performances in terms<br />

of the n–index versus critical current relation of constituting strands, characterized under simultaneous<br />

pre–compression and ben<strong>di</strong>ng strain.<br />

Role of the cross section geometry in rectangular Nb 3<br />

Sn CICC performances<br />

Parameters such as cable twist pitch (TP) and void fraction (VF) have a strong impact on CICC performances.<br />

A proper choice of their values in the <strong>di</strong>rection of raising TP and lowering VF has been proven to considerably<br />

enhance the transport properties, though increasing the AC losses, and to appreciably reduce the conductor<br />

degradation with electromagnetic and thermal loa<strong>di</strong>ng cycles. It has also been demonstrated that a further<br />

route for the improvement of CICCs’ performance is represented by a suitable optimization of the conductor<br />

shape as to the electromagnetic force <strong>di</strong>stribution. In this sense, CIC conductors with high aspect ratio<br />

rectangular geometry, if properly oriented, have shown a better response to high electromagnetic pressure, as<br />

proved by experimental evidences.<br />

The test results of a large rectangular Nb 3<br />

Sn CICC have been interpreted, thus conclu<strong>di</strong>ng that a high aspect<br />

ratio rectangular cross section helps in preventing performance degradation in CICCs and offers, if properly<br />

oriented as to the electromagnetic load, a better support to the strands, thus limiting the ben<strong>di</strong>ng strain effects.<br />

4.2 R&D on Superconducting Materials<br />

Study on Nb 3<br />

Sn strands<br />

Direct measurement of transversal resistance in Nb 3<br />

Sn strands. The first <strong>di</strong>rect measurement of the interfilament<br />

resistance vs. temperature by using a 4–probes method has been realized at <strong>ENEA</strong> Frascati and<br />

applied to Nb 3<br />

Sn samples as well as to NbTi ones, also inclu<strong>di</strong>ng the effect of a background magnetic field<br />

(0–3 T) at low temperatures.<br />

This activity, started in 2009 and still going on, lead to the clarification of the role of copper in lowering the<br />

measured resistance. This fact has been demonstrated, both in the NbTi and Nb 3<br />

Sn strands, making use of<br />

auxiliary samples with a reduced thickness of the outer stabilizing copper shell. The tranverse resistance R t<br />

of<br />

NbTi strands, which have a pure copper matrix, resulted to be an order of magnitude lower than that of the<br />

Internal–Tin Nb 3<br />

Sn samples and this is acceptable considering the presence of bronze in the strand<br />

cross–section.<br />

This higher resistivity in Nb 3<br />

Sn samples in turn plays a role in determining the ac losses, thermal stability, and<br />

sensitivity to the wire’s mechanical ben<strong>di</strong>ng. A 2D FEM model of the wire cross section has been developed<br />

which allows the per–unit length electrical conductance matrix between filament bundles at <strong>di</strong>fferent<br />

temperatures to be computed. The experimental and numerical results confirm that this matrix has a strong<br />

temperature dependence. The transverse electrical parameters computed with the 2D model are then<br />

implemented in a 3D lumped parameter non-linear electrical circuit that describes the entire wire sample<br />

under test.<br />

X–ray <strong>di</strong>ffraction measurements. <strong>ENEA</strong> is carrying on high–resolution x–ray <strong>di</strong>ffraction measurements at the<br />

high–energy scattering beamline ID15B of the ESRF in Grenoble. The lattice parameters, averaged over<br />

several Nb 3<br />

Sn peaks along both axial and transverse orientations, have been computed for the bare and the<br />

jacketed wires as function of the applied composite strain. Starting from a zero applied stress, the application<br />

of the axial stress causes the lattice cell to relax its pre–compression in the axial <strong>di</strong>rection, and to increase the<br />

compression in the ra<strong>di</strong>al one. A cubic cell is again obtained at an applied tensile strain of 0.094% in the bare<br />

strand and of 0.564% in the steel reinforced one.<br />

A much larger strain range (up to about 1.1%) is allowed to take place in the stainless steel reinforced wire as<br />

to the bare wire (up to about 0.5%), thus suggesting an important hint toward the improvement of the strain<br />

tolerance in such systems. In fact, the application of the outer steel reinforcement is not accompanied by a loss<br />

in performances, since the maximum in the critical current vs. axial strain curve is maintained in the jacketed<br />

wire, as compared to the bare one.


092<br />

progress report<br />

2010<br />

Critical current dependence on axial strain in stainless steel jacketed Nb 3<br />

Sn wires. The critical current of an<br />

internal tin Nb 3<br />

Sn wire developed by Oxford Instruments Superconducting Technology for ITER has been<br />

stu<strong>di</strong>ed under axial strain at fields between 12 T and 19 T≅4.2 K. Simulating the situation in a cable in<br />

conduit, where thermally induced compressive strain is important, the same wire was jacketed with AISI 316L<br />

stainless steel. The reinforced wire shows an important increase of ε m<br />

, the applied strain where the critical<br />

current I c<br />

reaches its maximum, from 0.25% to 0.57%. In ad<strong>di</strong>tion the irreversibility limit, ε irr<br />

, is improved<br />

from 0.50% applied strain to >1.10%. It could also be shown that the I c<br />

at zero intrinsic strain is almost<br />

identical. This demonstrates that jacketing does not influence the physical parameters of the original wire.<br />

Experimental data of the bare wire has been well fitted by <strong>di</strong>fferent strain functions. However, it was not<br />

possible to adequately model the data of the jacketed wire. There are in<strong>di</strong>cations that only models, which take<br />

into account the multi<strong>di</strong>mensional character of strain are able to describe the behaviour, but further<br />

development is required.<br />

Study on NbTi strands<br />

Test results of the Chinese NbTi wire for the ITER poloidal field magnets: a validation of the 2–pinning<br />

components model. A two–component model has been developed in the past years at <strong>ENEA</strong> in order to<br />

describe the normalized bulk pinning force curves and the critical current density of NbTi strands over a wider<br />

B–T range as compared to conventional single–component models. The model was previously successfully<br />

applied to data collected on several NbTi commercial strands. For further validation, we have extensively<br />

tested a strand recently produced by the Chinese Company Western Superconducting Technologies (fig. 4.5)<br />

for the ITER PF magnets PF2 to PF5, and applied the model to these data. In order to take into account the<br />

observed non–scaling with temperature of the reduced pinning force curves, the model has been updated by<br />

inclu<strong>di</strong>ng the observed <strong>di</strong>fference in the temperature dependences of the two components, thus contributing<br />

to the overall bulk pinning force.<br />

Critical current density (A/mm2)<br />

4<br />

2<br />

0<br />

0<br />

×103<br />

8.5 K<br />

4.2 K<br />

Transport J c<br />

4.2 K<br />

5.0 K<br />

5.5 K<br />

6.0 K<br />

6.2 K<br />

6.5 K<br />

7.0 K<br />

7.5 K<br />

8.0 K<br />

4 8<br />

Field induction (T)<br />

Magn. J c<br />

4.2 K<br />

5.0 K<br />

5.5 K<br />

6.0 K<br />

6.5 K<br />

7.0 K<br />

7.5 K<br />

8.0 K<br />

8.5 K<br />

2-components<br />

Fit<br />

4.2 K<br />

5.0 K<br />

5.5 K<br />

6.0 K<br />

6.2 K<br />

6.5 K<br />

7.0 K<br />

7.5 K<br />

8.0 K<br />

8.5 K<br />

Figure 4.5 – Superconductor transport (large<br />

symbols) and magnetization (small symbols)<br />

current density as function of the magnetic<br />

field, in the temperature range 4.2 K to 8.5 K<br />

F p<br />

= F p (1) + F p (2) = C 1·(1 t n ) 1·b 1·(1 b) 1 + C 2·(1 tn ) 2 ·b 2 ·(1 b) 2<br />

With reduced field and temperature defined as follows:<br />

b=B/B irr<br />

(T) = B/B irr_0<br />

(1-t n ); t = T / T c0<br />

the importance of testing wires over very wide temperature<br />

ranges is evidenced, and the good agreement between<br />

experimental and fit results validate the proposed formulation. It<br />

can be regarded as a reliable tool for the description of NbTi<br />

performances, to be used in the design of superconducting<br />

magnets. From the phenomenological point of view, it is shown<br />

that, at low temperatures, the two pinning mechanisms<br />

contribute to the bulk pinning force, thus resulting in pinning force peaking at a reduced field B/B irr<br />

≅0.5. As<br />

the temperature increases, the pinning force peak moves to lower fields, thus in<strong>di</strong>cating that the low field<br />

component pinning mechanism becomes dominant.<br />

Quality control monitoring of NbTi strands for JT–60SA TF coils<br />

<strong>ENEA</strong> was awarded a contract from F4E (F4E–BOA–004 (MS–MG)) for the performance of quality controls<br />

in support of the evaluation process of industrial offers and for an in depth monitoring of the NbTi strand<br />

production for JT–60SA TF conductor. The TF conductor is a CICC, and relies on twisted multifilament<br />

NbTi–based composite strands with copper strands cabled and than jacketed to become a CICC. The<br />

characterization of the superconducting strands in the temperature and magnetic field range of interest is in<br />

fact a fundamental step in the design of a magnet for a tokamak reactor, based on them. During 2010 three<br />

NbTi strands have been characterized at the <strong>ENEA</strong> Variable Temperature facility in terms of transport critical<br />

current and n–value at various temperatures.


superconductivity (cont’d.)<br />

progress report<br />

2010<br />

093<br />

ITER NbTi strand benchmarking tests<br />

Scope of this task was to test the performances and layout of<br />

a NbTi strand intended for the ITER PF coils, as a<br />

benchmark of <strong>di</strong>fferent test facilities. Strand characterization<br />

has been performed at <strong>ENEA</strong> in terms of strand layout<br />

(<strong>di</strong>ameter and twist pitch length), transport critical current<br />

and n–value at liquid helium, hysteresis losses by<br />

magnetization technique, critical current as function of<br />

temperature, by magnetization technique (formally not<br />

foreseen by the benchmarking activity), transport critical<br />

current and n–value at variable temperature (formally not<br />

foreseen by the benchmarking activity). Superconducting<br />

critical current density (J c<br />

) is shown in figure 4.6.<br />

4.3 High Temperature Superconductors<br />

Figure 4.6 – Superconductor Jc extracted from<br />

magnetization data, carried out at <strong>di</strong>fferent<br />

temperatures (small dots), as compared to<br />

transport data collected at the <strong>ENEA</strong> VTI facility<br />

(large symbols). The data measured in the <strong>ENEA</strong><br />

liquid helium facility are also reported (green<br />

square symbols) for comparison<br />

0 4 8<br />

Field induction (T)<br />

The activity of the laboratory on High Temperature Superconductors (HTS) was focused on the development<br />

and characterization of coated conductor (CC) tapes based on films of YBa 2<br />

Cu 3<br />

O 7–X<br />

(YBCO) and their<br />

application. In particular, the activities can be grouped as follows:<br />

i) Coated conductor processing. Exploitation of the innovative low-fluorine chemical deposition for high current<br />

YBCO films and development of a more robust and economic oxide buffer layer architecture suitable for<br />

alternative copper based metallic substrates. These activities have been carried out in collaboration with<br />

Technical University of Cluj (Romania), Physics Department of “Tor Vergata” Rome University, Institute<br />

of Material Science of Consiglio Nazionale delle Ricerche (CNR) and Physics Department of Roma TRE<br />

University;<br />

ii) Conceptual design of the construction of toroidal field based on HTS–coils for a tokamak machine. This work was aimed<br />

at the upgra<strong>di</strong>ng of the Istituto Superior Técnico Tokamak (ISTTOK) machine and has been carried out<br />

in cooperation with Portuguese and Slovak EURATOM Associations.<br />

Critical current density (A/mm2)<br />

4<br />

2<br />

0<br />

×103<br />

Transport (VTI) Magnetization<br />

3.5 K<br />

4.2 K<br />

4.2 K<br />

5.0 K<br />

5.0 K<br />

6.0 K<br />

6.0 K<br />

7.0 K<br />

7.0 K<br />

8.0 K<br />

7.5 K<br />

8.5 K<br />

4.2 K_LHe test facility<br />

Study of Ni–Cu based alloy tapes for YBCO coated conductor application<br />

Ni–Cu (Ni with 50 at% Cu) alloy based substrates are currently stu<strong>di</strong>ed at <strong>ENEA</strong> in order to obtain substrates<br />

with interme<strong>di</strong>ate characteristics between Ni and Cu. To stabilize the microstructure of the binary Ni–Cu<br />

alloy, 3 at% Co was added (Ni–Cu–Co). This alloy tape develops<br />

a rather sharp cube structure, with a fraction around 97% of<br />

cubic grains. The alloy is stronger than either the pure metals or<br />

T c0 = 86.6 K<br />

the binary Ni–Cu and shows a yield strength of around 120 MPa<br />

at 0.2% offset. Ni–Cu–Co shows a reduced magnetism as<br />

compared to the currently employed Ni–W alloy, since the Curie<br />

temperature is around 155 K. This alloy substrate was successfully<br />

used for the realization of high J c<br />

YBCO films. The film is mainly<br />

104<br />

c–axis oriented with a minor fraction of a–axis grains. A J c<br />

of<br />

about 1.1 MA cm –2 was measured (fig. 4.7).<br />

Another solution was the substitution of Co with W. A very strong<br />

cube texture is obtained only for W content around 0.5 at%<br />

(Ni–Cu–W), with a fraction of cubic grains around 99% without<br />

secondary recrystallization. This alloy is as strong as Ni–Cu–Co<br />

and is nonmagnetic at 77 K, since the Curie temperature is<br />

22.5 K. A more suitable MgO–based buffer layer architecture was<br />

stu<strong>di</strong>ed. MgO film was epitaxially deposited by e–beam<br />

evaporation in H 2<br />

O atmosphere at temperature as low as 400°C.<br />

A 10 nm– thick Pd seed layer was used to promote MgO epitaxy.<br />

The x–ray θ–2θ spectrum shows that the MgO film is well<br />

Critical current density (A cm-2)<br />

10 6 10 nm<br />

2 4 6<br />

1000<br />

100<br />

0<br />

Magnetic induction (T)<br />

Figure 4.7 – Critical current density as a<br />

function of the magnetic induction J c (B) for<br />

a YBCO/CeO 2 /YSZ/CeO 2 sample grown on<br />

Pd–buffered Ni–Cu–Co substrate. In the<br />

inset, the cross section of the multilayer<br />

architecture is shown


094<br />

progress report<br />

2010<br />

Intensity (Arb. units)<br />

1200<br />

800<br />

400<br />

As grown<br />

Annealed<br />

42 43<br />

(200) MgO<br />

0<br />

35 45 55<br />

2θ (deg)<br />

Figure 4.8 – X–ray <strong>di</strong>ffraction θ–2θ scan of MgO<br />

film grown on Pd–buffered Ni–Cu–W. The<br />

spectra refer to the as–grown sample (full<br />

dots) and after annealing at 800 °C in vacuum<br />

(empty dots). In the inset, a detail of (200)MgO<br />

peaks. The thickness of MgO, Pd and Ni–Cu–W<br />

is 120 nm, 10 nm and 50 mm, respectively<br />

Realtive–peak–to–peak<br />

intensity (Arb. units)<br />

2×10 3<br />

a)<br />

(200) Pd<br />

b)<br />

(200) Ni–Cu–W<br />

Zr<br />

Y<br />

O<br />

Ce<br />

Ni<br />

Pd<br />

0 400 800<br />

oriented (fig. 4.8). The MgO layer is adequate for the<br />

deposition of a cap layer before YBCO deposition as tested by<br />

the heat treatment at 800 °C in vacuum.<br />

Oxidation behaviour of the Ni–W and CeO 2<br />

interface: role of<br />

Pd inter–layer<br />

Considering that oxidation at the substrate interface could<br />

influence the epitaxial growth and the mechanical stability of<br />

the whole coating architecture, the role of the Pd interlayer at<br />

the interface between NiW and CeO 2<br />

/YSZ/CeO 2<br />

buffer layer<br />

structure has been stu<strong>di</strong>ed by x–ray techniques and electron<br />

Auger spectroscopy. Extended x–ray absorption fine structure<br />

(EXAFS) analyses reveal that the inter–<strong>di</strong>ffusion process<br />

between the Pd layer and the substrate mo<strong>di</strong>fies the substrate<br />

interface composition due to the formation of an ordered<br />

Ni–Pd alloy even at temperatures as low as 600°C. At high<br />

temperatures, the oxidation mechanism is dependent on the Pd<br />

layer thickness, and competition between the NiO and the<br />

NiWO 4<br />

formation is observed. Oxidation also affects the CeO 2<br />

interface with the substrate. Auger electron spectroscopic (AES)<br />

analyses, reported in figure 4.9, reveal that the interface region<br />

is more extended than that of samples in vacuum annealed,<br />

and that outward migration of Ni and Pd in the CeO 2<br />

layer<br />

occurs. The CeO 2<br />

layer contamination results to be reduced as<br />

the Pd layer increases. The lower CeO 2<br />

contamination and the<br />

lower NiO formation could be associated to the good adhesion<br />

obtained in coated conductor samples with a Pd interlayer.<br />

4×10 3 400 800 1200 1600<br />

Realtive–peak–to–peak<br />

intensity (Arb. units)<br />

0<br />

0<br />

8×10 4<br />

4×10 4<br />

Sputtering time (s)<br />

c)<br />

Zr<br />

Y<br />

O<br />

Ce<br />

Ni<br />

Pd<br />

0<br />

0 400 800 1200 1600<br />

Sputtering time (s)<br />

Figure 4.9 – AES depth profiles for CeO 2 /YSZ<br />

samples deposited on Ni–W substrate buffered<br />

with a 50 nm Pd over layer annealed at 800 °C<br />

a) in vacuum and b) in 10 mTorr of oxygen back<br />

ground pressure. c) AES depth profiles for<br />

CeO 2 /YSZ samples deposited on Ni–W<br />

substrate buffered with a 200 nm Pd over layer<br />

annealed at 800 °C in 10 mTorr of oxygen back<br />

ground pressure. W signal is multiplied for 50<br />

Low fluorine YBCO MOD<br />

In this low fluorine method, only the Ba precursor is introduced<br />

in the coating solution as a trifluoroacetate, while other<br />

precursors are (Cu and Y)–acetate treated with an excess of<br />

propionic acid. The reaction path for YBCO formation was<br />

investigated by x–ray photoelectron spectroscopy (XPS) and<br />

<strong>di</strong>ffraction (XRD). From these analyses it resulted that the<br />

YBCO formation occurs through a rather complex mechanism<br />

involving hydrolysis of both Y and Ba fluorides and the<br />

reaction with CuO. However, this path is probably hindered by<br />

a competing reaction taking place at the same temperature<br />

range as YBCO formation (around 700–800°C). In figure 4.10,<br />

the evolution of the reaction path can be derived through<br />

x–ray <strong>di</strong>ffraction θ–2θ patterns. Within the 700–795°C<br />

temperature range the YBCO phase coexists with both<br />

Y 2<br />

Cu 2<br />

O and BaF 2<br />

phases. At 795°C, the XRD spectrum<br />

shows the presence of sharp and intense (00l) reflection of<br />

YBCO together with other <strong>di</strong>stinct peaks ascribable to the<br />

presence of residual Y 2<br />

Cu 2<br />

O 5<br />

phase, while BaF 2<br />

phase<br />

<strong>di</strong>sappears.<br />

Transport properties improvement in low fluorine YBCO MOD with artificial pinning sites<br />

The possibility of enhancing the pinning efficiency by means of artificial pinning sites created by ad<strong>di</strong>tion of<br />

BaZrO 3<br />

(BZO) has been investigated in YBa 2<br />

Cu 3<br />

O 7–x<br />

(YBCO) films grown by metallorganic decomposition<br />

(MOD) methods. YBCO and BZO coating solutions were prepared and subsequently mixed in molar ratios<br />

correspon<strong>di</strong>ng to 5, 7.5, 10, 15 mol.% BZO. A marked increase in the J c<br />

(0) value has been measured in MOD


superconductivity (cont’d.)<br />

progress report<br />

2010<br />

095<br />

Intensity (Arb. units)<br />

(0.04)<br />

(0.05)<br />

26 30 34 38 42<br />

2θ(Deg)<br />

*<br />

795°C+10<br />

795°C<br />

750°C<br />

725°C<br />

700°C<br />

550°C<br />

Pyrolysed<br />

Figure 4.10 – XRD analyses for the samples<br />

quenched at <strong>di</strong>fferent temperatures. Continuous line<br />

represent the Ba(O,F) reflection, while dashed line<br />

are the peak ascribable to the Y 2 Cu 2 O 5 phase. (004)<br />

and (005) are two reflection of the YBCO film, while<br />

* is a substrate feature<br />

Pinning force density (GN/m3)<br />

10 11 a)<br />

10 9<br />

10 7<br />

(MOD)YBCO<br />

82 K<br />

65 K<br />

77 K<br />

10 5 0.1 1 10<br />

Magnetic induction (T)<br />

10 K<br />

30 K<br />

50 K<br />

Critical current density (A/m 2 )<br />

10 5 T=77 K<br />

10 3<br />

10 1<br />

10 -1<br />

10 -3<br />

10- 5<br />

Correlated<br />

Isotropic<br />

γ=4<br />

4 T<br />

6 T<br />

8 T<br />

-20 20 60 100<br />

Angle (degree)<br />

b)<br />

Figure 4.11 – a) Pinning force<br />

densities of pure YBCO (red)<br />

and 10 mol. % YBCO–BZO<br />

(blue) measured as a function<br />

of the applied field at several<br />

temperatures; b) critical<br />

current density as a function<br />

of the applied field <strong>di</strong>rection<br />

measured for 10 mol.%<br />

YBCO–BZO at 77 K at <strong>di</strong>fferent<br />

field field intensity. The green<br />

line represent the isotropic<br />

contribution while the black<br />

arrow shows the correlated<br />

contribution at 0° and 8 T<br />

0.5<br />

0<br />

-0.5<br />

0.4<br />

0.2<br />

0<br />

-0.2<br />

Figure 4.12 – Map of the magnetic flux density axial component B z<br />

in the plane of the coil generated by the actual copper coil and by<br />

one of the proposed version of superconducting coil having the<br />

same internal bore. Copper coil characteristics: I op = 8 kA, coil is a<br />

stack of 8 layer connected in series. HTS coil: I op =100 A, coil is<br />

obtained as a stack of 2 layer with 320 turns each<br />

0.8<br />

0.4<br />

0<br />

-0.4<br />

films, even though a clear dependence of J c<br />

(0) values on the BZO content cannot be established. The results,<br />

as shown in figure 4.11, revealed an improvement in the pinning efficiency if compared with pure YBCO<br />

samples, as evidenced by the upward shift of the irreversibility field value (from 6.8 T to 8 T) and the increase<br />

in the maximum pinning force density (from 4.5 to 11.5 GN/m 3 ) measured at 77 K. This result is consistent<br />

with the presence of the BZO nano–particles acting as ad<strong>di</strong>tional pinning sources.<br />

Conceptual design of YBCO coil for the toroidal magnetic system of ISTTOK tokamak<br />

The aim of this activity is to evaluate the possibility of operating ISTTOK tokamak with a HTS toroidal<br />

magnetic field, thus allowing a continuous operation in steady state. The feasibility of a tokamak operating<br />

with HTS is extremely relevant and ISTTOK is the ideal can<strong>di</strong>date for a meaningful test in this sense, due to<br />

its small size, the possibility to operate in a steady–state inductive operation and therefore at lower cost. A finite<br />

element analysis has been carried out to calculate the <strong>di</strong>stribution of magnetic field components. It is found<br />

that the operation at 77 K with 0.45 Tesla field on plasma axis would require 17 km of 12 mm wide tape<br />

commercially available today. In Figure 4.12 the maps of the magnetic flux density axial component as<br />

obtained from numerical analysis for a single actual copper a) and HTS coil b) are plotted.


096<br />

progress report<br />

2010<br />

chapter 5<br />

inertialfusion<br />

The research activity on the ABC facility is now restarting after a shut down of about one year. New<br />

calibrations of the laser outputs are on going. The scientific program is being revised in the light of a possible<br />

upgrade of the laser power or the pulse time shape. Digitization of the alignment and <strong>di</strong>agnostics sensor is<br />

under implementation.<br />

As a possible follow up of the ABC activity, the ABC team has designed a 200 J <strong>di</strong>ode pumped laser. Accor<strong>di</strong>ng<br />

to this preliminary study, a prototype sector of a <strong>di</strong>ode illuminating head has been designed and is presently<br />

under realisation. The first tests will be devoted to checking the emission spectrum of the <strong>di</strong>odes under<br />

operation, a de<strong>di</strong>cated fast time response spectrograph has been commissioned. A provisional cooling system<br />

for a 25–30 <strong>di</strong>ode brick has been designed and is now undergoing further investigation (fig. 5.1).<br />

Figure 5.1 – The ABC target repository, positioning<br />

manipulator and holder


progress report<br />

2010<br />

097<br />

chapter 6<br />

fusion&industry<br />

In 2010, the construction of ITER has entered an important phase with the calls for tender for the largest<br />

components of the reactor itself and the buil<strong>di</strong>ngs on the European site in Cadarache (France). The activities<br />

of the Italian Industry Liaison Office for ITER (ILO) have also decisively stepped up in strengthening the<br />

involvement of the Italian industry in the construction of ITER.<br />

Beside the information service announcing all calls for tender published by Fusion For Energy (F4E), several<br />

initiatives were taken with the purpose of raising awareness and sprea<strong>di</strong>ng information to potential<br />

contractors, which were also assisted in understan<strong>di</strong>ng the technical content and the requirements of the above<br />

mentioned calls.<br />

• The ILO organised the Italian industry participation in the Fusion Technology Forum Exhibition in the<br />

frame of the Symposium on Fusion Technology (SOFT 2010), held in Porto (Portugal) in September. The<br />

Forum brought together hundreds of industries and research laboratories from all over Europe.<br />

• A meeting was organized at <strong>ENEA</strong> Frascati Centre on February 26th to illustrate the European<br />

procurement packages on ITER Remote Handling, with the participation of experts from ITER IO and<br />

F4E. About forty participants from twenty companies attended the meeting.<br />

• A seminar on ITER International Project for Fusion Energy was held during the CERN workshop<br />

Opportunità per le Aziende, held in Turin on October 6th, 2010.<br />

The close collaboration with the F4E Business Intelligence Group has been strengthened. A number of Italian<br />

companies have been introduced in F4E, and to the ILOs of other European Countries in order to create<br />

opportunities for the formation of consortia at a European level. The ILO also promoted the participation of<br />

Italian companies in the F4E Information Meetings on Neutral Beam Test Facility in Padua (Italy, 18<br />

November) and on Buil<strong>di</strong>ngs for ITER (22 November), and in the First Monaco ITER International Fusion<br />

Energy Days (23–25 November). All these initiatives have received a considerable interest and have been<br />

attended by a growing number of participants.<br />

The participation of Italian industries in F4E competitive tenders has been extremely successful in 2010: at<br />

the end of the year a total of 25 industrial contracts have been awarded to Italian companies for a total value<br />

of more than 500 millions € (on a total of 1000 millions € awarded by F4E since 2007). The major contracts<br />

were related to the supply of critical components and greater technological content that make up the core of<br />

the reactor (vacuum vessel, toroidal field coil win<strong>di</strong>ng packs, toroidal and poloidal field coil conductors,<br />

<strong>di</strong>vertor targets, power supplies (fig. 6.1).


098<br />

progress report<br />

2010 fusion & industry (cont’d.)<br />

Figure 6.1 – Researchers of the <strong>ENEA</strong> Fusion Technical<br />

Unit visiting the Walter Tosto Spa in Chieti (Italy). Walter<br />

Tosto with Ansaldo Nucleare and Mangiarotti has been<br />

awarded the contract for the supply of the ITER vacuum<br />

vessel. In the picture, together with <strong>ENEA</strong><br />

representatives, the company Business Development<br />

Manager and some of the fifteen young engineers hired<br />

by Walter Tosto for the realization of the vacuum<br />

chamber of ITER. They all are enthusiast for the<br />

opportunity they have given to work for a large<br />

international project, highly technological and<br />

innovative, and with strict quality management: a unique<br />

experience for their professional development, and a<br />

positive example in the current youth employment crisis<br />

In the framework of Euratom – Fusion, the European Commission has established a forum de<strong>di</strong>cated to the<br />

development of innovative fusion reactor technologies with the involvement of industry. The Fusion Industry<br />

Innovation Forum will aim to involve the industry in elaborating the fusion energy development strategy, with<br />

a view to its implementation in the time specified by the SET Plan. In particular, it will provide the tool to<br />

develop a technology roadmap, produce the required industrial innovation, increase opportunities to transfer<br />

know–how between research laboratories and industry, and develop the necessary human capacity. As a first<br />

step in this <strong>di</strong>rection, it proceeded with the consultation of industry representatives in various EU countries.<br />

In this context, in March 2010, <strong>ENEA</strong> organized a meeting at its headquarter, with the participation of a<br />

representative of the European Commission – Euratom and the major Italian industry players in the field of<br />

fusion and energy in general, with the aim of gathering views and suggestions for the creation of such a forum.<br />

Two Italian representatives are now members of the Fusion Industry Innovation Forum.


progress report<br />

2010<br />

099<br />

chapter 7<br />

Qualityassurance<br />

Throughout 2010 <strong>ENEA</strong> – Unità Tecnica <strong>Fusione</strong> (UTFUS) has been carrying on the activities of<br />

establishing, documenting and implementing a Quality Management System (QMS) in accordance with the<br />

ISO 9001:2008 requirements.<br />

The main steps undertaken towards the final implementation have been:<br />

• Start–up of the certification process of<br />

the QMS (pre–au<strong>di</strong>t and stage 1 au<strong>di</strong>t<br />

performed)<br />

• Definition of the certification scope of<br />

the QMS as follows: “Design,<br />

development and experimental tests<br />

of components and systems for<br />

magnetic thermonuclear fusion plants,<br />

inclu<strong>di</strong>ng construction of related test<br />

prototypes. Advanced stu<strong>di</strong>es to<br />

support magnetic thermonuclear<br />

fusion”<br />

• Determination of the main processes<br />

needed for the QMS and their<br />

application. They are: i) experimental<br />

activities, ii) design activities, iii)<br />

construction of plants or<br />

components/prototypes usually<br />

designed inside UTFUS<br />

• Issue of the quality management<br />

system documentation inclu<strong>di</strong>ng: a)<br />

the documented statements of a<br />

Table 7.I – List of the prodcedure<br />

Procedure<br />

PGQ 01<br />

PGQ 02<br />

PGQ 03<br />

PGQ 04<br />

PGQ 05<br />

PSO 01<br />

PSO 02<br />

PSO 03<br />

PSO 04<br />

PSO 05<br />

PSO 06<br />

PSO 07<br />

PSO 08<br />

PSO 09<br />

PSO 10<br />

quality policy and quality objectives; b) the Quality Manual; c) 15 documented procedures; some (5)<br />

required by the ISO 9001:2008 and others (10) customised accor<strong>di</strong>ng to type of activities, complexity of<br />

processes and their interactions; d) work instructions.<br />

• Communication to the staff about establishment, documentation and implementation of the quality<br />

management system, carried out through 8 seminars (involving 94% of the staff)<br />

• Establishment and completion of internal au<strong>di</strong>ts<br />

• Data collection of instrumentation and reference codes.<br />

• Collection and analysis of data aiming to demonstrate the suitability and effectiveness of the QMS and to<br />

evaluate where continual improvement can be pursued.<br />

The list of 15 documented procedures is reported in the following table 7.I. The entire QMS documentation<br />

is available to all staff at the <strong>ENEA</strong> UTFUS de<strong>di</strong>cated web page http://www.fusione.enea.it/<br />

PROJECTS/sgq/index.html.en<br />

Title<br />

Management and control of documents<br />

Internal au<strong>di</strong>ts<br />

Management of non conformities<br />

Management of preventive and corrective actions<br />

Management and control of records<br />

Management of Human Resources<br />

Management of experimental activities<br />

Management of design activities<br />

Management of construction of prototypes or plants<br />

Procurement/supplying and management of supplies<br />

Management of measuring instruments<br />

Management of special processes<br />

Data analysis<br />

Guideline for the preparation of quality plans<br />

Supplying, storage and traceability of consumables


100<br />

progress report<br />

2010<br />

chapter 8<br />

publicationsandevents<br />

8.1 Publications<br />

Articles<br />

A. BIERWAGE, L. CHEN, F. ZONCA: Pressure–gra<strong>di</strong>ent–induced Alfvén eigenmodes: I. Ideal MHD and finite ion Larmor ra<strong>di</strong>us effects,<br />

Plasma Phys. Control. Fusion 52, 015004 (2010)<br />

A. BIERWAGE, L. CHEN, F. ZONCA: Pressure–gra<strong>di</strong>ent–induced Alfvén eigenmodes: II. Kinetic excitation with ion temperature gra<strong>di</strong>ent,<br />

Plasma Phys. Control. Fusion 52, 015005 (2010)<br />

R. VILLARI, A. CUCCHIARO, B. ESPOSITO, D. MAROCCO, F. MORO, L. PETRIZZI, A. PIZZUTO, G. BROLATTI: Neutronic analysis of FAST,<br />

IEEE Trans. Plasma Sci. 38, 3, 406–413 (2010)<br />

A. CUCCHIARO, R. ALBANESE, G. AMBROSINO, G. BROLATTI, G. CALABRÒ, V. COCILOVO, A. COLETTI, R. COLETTI, P. COSTA, P. FROSI, F.<br />

CRESCENZI, F. CRISANTI, G. GRANUCCI, G. MADDALUNO, V. PERICOLI–RIDOLFINI, A. PIZZUTO, C. RITA, G. RAMOGIDA: Conceptual design<br />

of the FAST load assembly, Fusion Eng. Des. 85, 174–180 (2010)<br />

C. RIZZELLO, F. BORGOGNONI, T. PINNA, S. TOSTI: Review of tritium confinement and atmosphere detritiation system in hot cells<br />

complex, Fusion Eng. Des. 85, 58–63 (2010)<br />

M. SORBA, D. MILANESIO, R. MAGGIORA. A.A. TUCCILLO: Optimization of the FAST ICRF antenna using TOPICA code, Fusion Eng. Des.<br />

85, 161–168 (2010)<br />

Y. HYROOKA, G. MAZZITELLI, S.V. MIRNOV, M. ONO, M. SHIMADA and F.L. TABARES: Conference report on the 1st International Workshop<br />

on Li–applications to boundary control in fusion devices, Nucl. Fusion 50, 077001–077004 (2010)<br />

B. ESPOSITO, F. MURTAS, R. VILLARI, M. ANGELONE, D. MAROCCO, M. PILLON, S. PUDDU: Design of a GEM–based detector for the<br />

measurement of fast neutrons, Nucl. Instrum. Meth. Phys. Res. A 617, 155–157 (2010)<br />

A. DELLA CORTE, V. CORATO, A. DI ZENOBIO, C. FIAMOZZI ZIGNANI, L. MUZZI, G.M. POLLI, L. RECCIA, S. TURTÙ, P. BRUZZONE, E.<br />

SALPIETRO, A. VOSTENER: Successful performances of the EU–AltTF sample, a large size Nb 3 Sn cable-in-conduit conductor with<br />

rectangular geometry, Supercond. Sci. Technol. 23, 045028–045033 (2010)<br />

S. ALMAVIVA, M. MARINELLI, E. MILANI, G. PRESTOPINO, A. TUCCIARONE, C. VERONA, G. VERONA RINATI, M. ANGELONE, M. PILLON:<br />

Improved performance in synthetic <strong>di</strong>amond neutron detectors: application to boron neutron capture therapy, Nucl. Instrum. Meth. Phys.<br />

Res. A 612, 580–582 (2010)<br />

D. PACELLA, G. PIZZICAROLI, D. MAZON, P. MALARD: A method for detecting layers or dust deposited on tokamak surfaces, Fusion Sci.<br />

Technol. 57, 2, 142–151 (2010)<br />

E. VISCA, A. PIZZUTO, S. ROCCELLA: Tecnologie per la costruzione <strong>di</strong> componenti ad alto flusso termico per reattori a fusione, Proc. 28th<br />

UIT Heat Transfer Congress, Eds. M. Pilotelli and G.P. Beretta, Univesità <strong>di</strong> Brescia, p. 385–390 (2010)<br />

Y. SADEGHI, G. RAMOGIDA, L. BONCAGNI, C. D’EPIFANIO, V. VITALE, F. CRISANTI, L. ZACCARIAN: Real–time reconstruction of plasma<br />

equilibrium in FTU, IEEE Trans. Plasma Sci. 38,3, 352-358 (2010)<br />

L. MUZZI, V. CORATO, G. DE MARZI, A. DI ZENOBIO, C. FIAMOZZI ZIGNANI, L.RECCIA, S. TURTÙ, A. DELLA CORTE, P. BARABASCHI, M.<br />

PEYROT, P. BRUZZONE, B. STEPANOV: The JT–60SA toroidal field conductor reference sample: manufacturing and test results, IEEE<br />

Trans. Appl. Supercond. 20,3, 442–446 (2010)<br />

A. DI ZENOBIO, A. DELLA CORTE, L. MUZZI, A. BRAGAGNI, A. TANGUENZA, D. VALORI, A. BALDINI, D. BESSETTE, A. DEVRED, A. VOSTNER:<br />

Conductor manufacturing of the ITER TF full–size performance samples, IEEE Trans. Appl. Supercond. 20,3, 1412–1415 (2010)


publications and events (cont’d.)<br />

progress report<br />

2010<br />

101<br />

ZHIYONG QIU, F. ZONCA, LIU CHEN: Nonlocal theory of energetic–particle–induced geodesic acoustic mode, Plasma Phys. Control.<br />

Fusion 52, 095003 (13pp) (2010)<br />

L. BONCAGNI, S. GALEANI, G.GRANUCCI, G. VARANO, V. VITALE, L. ZACCARIAN: Using dynamic input allocation for elongation control at<br />

FTU, Fusion Eng. Des. 85, 3-4, 443–446 (2010)<br />

A. PIZZUTO, F. GNESOTTO, M. LONTANO, R. ALBANESE, G. AMBROSINO, M.L. APICELLA, A. BRUSCHI, M. BARUZZO, G. CALABRO’, A. CARDINALI,<br />

R. CESARIO, F. CRISANTI, V. COCILOVO, A. COLETTI, R. COLETTI, P. COSTA, S. BRIGUGLIO, P. FROSI, F. CRESCENZI, V. COCCORESE, A. CUCCHIARO,<br />

C. DI TROIA, B. ESPOSITO, G. FOGACCIA, E. GIOVANNOZZI, G. GRANUCCI, G. MADDALUNO, R. MAGGIORA, M. MARINUCCI, D. MAROCCO, P.<br />

MARTIN, G. MAZZITELLI, F. MIRIZZI, S. NOWAK, R. PACCAGNELLA, L. PANACCIONE, G. L. RAVERA, F. ORSITTO, V. PERICOLI RIDOLFINI, G.<br />

RAMOGIDA, C. RITA, M. SCHNEIDER, A. TUCCILLO, R. ZAGÓRSKI, M. VALISA, R. VILLARI, G. VLAD, F. ZONCA: The Fusion Advanced Stu<strong>di</strong>es Torus<br />

(FAST): a proposal for an ITER satellite facility in support of the development of fusion energy, Nucl. Fusion 50, 095005 (15 pp) (2010)<br />

P. MICOZZI, F. ALLADIO, A. MANCUSO, F. ROGIER: Ideal MHD stability limits of the PROTO–SPHERA configuration, Nucl. Fusion 50,<br />

095004 (10 pp) (2010)<br />

A. BERTOCCHI, L. BONCAGNI, C. CENTIOLI, F. IANNONE, M. PANELLA, M. VELLUCCI, V. VITALE: Open source solutions in control and data<br />

acquisition systems: FTU case stu<strong>di</strong>es, Fusion Eng. Des. 85, 3-4, 321–324 (2010)<br />

B. GUILLERMINET, I. CAMPOS PLASENCIA, M. HAEFELE, F. IANNONE, A. JACKSON, G. MANDUCHI, M. PLOCIENNIK, E. SONNENDRUCKER,<br />

P. STRAND, M. OWSIAK, EUROPEAN TASK FORCE ON INTEGRATED TOKAMAK MODELLING ACTIVITY: High performance computing tools<br />

for the integrated tokamak modelling project, Fusion Eng. Des. 85, 3–4, 388–393 (2010)<br />

V.F. PAIS, S. BALME, H.S. AKPANGNY, F. IANNONE, P. STRAND: Enabling remote access to projects in a large collaborative environment,<br />

Fusion Eng. Des. 85, 3–4, 633–636 (2010)<br />

A. BIANCALANI, LIU CHEN, F. PEGORARO, F. ZONCA: Continuous spectrum of shear Alfvén waves within magnetic islands, Phys. Rev.<br />

Lett. 105,9, 095002(4) (2010)<br />

C. CASTALDO, A. CARDINALI: Tritium minority heating with mode conversion of fast waves, Phys. of Plasmas 17, 072513 (5 pp) (2010)<br />

X. WANG, F. ZONCA, L. CHEN: Theory and simulation of <strong>di</strong>screte kinetic beta induced Alfvén eigenmode in tokamak plasmas, Plasma<br />

Phys. Control. Fusion 52, 115005 (12pp) (2010)<br />

G.L. RAVERA, R. MAGGIORA, F. MIRIZZI, A.A. TUCCILLO: Performance of <strong>di</strong>fferent load tolerant external matching unit for the FAST–ICRH<br />

system, Proc. of the 40th European Microwave Conference, 1198–1201 (2010)<br />

A. VANNOZZI, A. ANGRISANI ARMENIO, A. AUGIERI, G. CELENTANO, V. GALLUZZI, A. MANCINI, T. PETRISOR, A. RUFOLONNI, GY.<br />

THALMAIER: Development and characterization of cube–texture Ni–Cu–Co substrates for YBCO coated conductors, Acta Materialia 58,<br />

910–918 (2010)<br />

G. CELENTANO, A. AUGIERI, A. MAURETTI, A.VANNOZZI, A. ANGRISANI ARMENIO, V. GALLOZZI, S. GAUDIO, A. MANCINI, A. RUFOLONI, I.<br />

DAVOLI, C. DEL GAUDIO, F. NANNI: Electrical and mechanical characterization of coated conductors lap joint, IEEE Trans. Appl.<br />

Supercond. 20, 3, 1549–1552 (2010)<br />

V. CORATO, L. MUZZI, A. AUGIERI, U. BESI VETRELLA, C. FIAMOZZI ZIGNANI, A. RUFOLONI, A. DELLA CORTE: Measurement of the<br />

transversal resistivity in superconducting strands with 4–probe technique, IEEE Trans. Appl. Supercond. 20, 3, 1630–1633 (2010)<br />

A. AUGIERI, G. CELENTANO, V. GALLUZZI, A. MANCINI, A. RUFOLONI, A. VANNOZZI, A. ANGRISANI ARMENIO, T. PETRISOR, L. CIONTEA, S. RUBANOV,<br />

E. SILVA, N. POMPEO: Pinning analyses on epitaxial YBa 2 Cu 3 O 7-‰ film with BaZrO 3 inclusions, J. Appl. Phys. 108, 063906,1–5 (2010)<br />

M. ANGELONE, M. PILLON, M. MARINELLI, E. MILANI, G. PRESTOPINO, C. VERONA, G. VERONA-RINATI, I. COFFEY, A. MURARI, N. TARTONI


102<br />

progress report<br />

2010<br />

AND JET–EFDA CONTRIBUTORS: Single crystal artificial <strong>di</strong>amond detectors for VUV and soft x–ray measurements on JET thermonuclear<br />

fusion plasma, Nucl. Instrum. Meth. Phys. Res. A 623, 726–730 (2010)<br />

R. CESARIO, L. AMICUCCI, C. CASTALDO, L. PANACCIONE, G. CALABRÒ, A. CARDINALI, C. CIANFARANI, M. MARINUCCI, C. MAZZOTTA,<br />

V. PERICOLI, O. TUDISCO, FTU TEAM: Current drive at plasma densities required for thermonuclear reactors, Nature Commun. 1:<br />

doi:10.1038/ncomms1052 (2010)<br />

R. DE ANGELIS, M. BARUZZO, P. BURATTI, B. ALPER, L. BARRERA, A. BOTRUGNO, M. BRIX, L. FIGINI, A. FONSECA, C. GIROUD, N.<br />

HAWKES, D. HOWELL, E. DE LA LUNA, F. ORSITTO, V. PERICOLI, E. RACHLEW, O. TUDISCO, and JET–EFDA CONTRIBUTORS: Localization<br />

of MHD modes and consistency with q profiles in JET, Nucl. Instrum. Meth. Phys. Res. A 623, 734–737 (2010)<br />

R. DE ANGELIS, L. DI MATTEO: Observations and analysis of FTU plasmas by video cameras, Nucl. Instrum. Meth. Phys. Res. A 623,<br />

815–817 (2010)<br />

M. GELFUSA, M. BROMBIN, P. GAUDIO, A. BOBOC, A. MURARI, F.P. ORSITTO, JET–EFDA CONTRIBUTORS: Modelling of the signal<br />

processing electronics of JET interferometer–polarimeter, Nucl. Instrum. Meth. Phys. Res. A 623, 660–663 (2010)<br />

J.R. MARTIN–SOLIS, R. SANCHEZ, B. ESPOSITO: Experimental observation of increased threshold electric field for runaway generation<br />

due to synchroton ra<strong>di</strong>ation losses in the FTU tokamak, Phys. Rev. Lett. 105, 185002(1–4) (2010)<br />

F.P. ORSITTO, A. BIBOC, P. GAUDIO, M. GELFUSA, E. GIOVANNOZZI, C. MAZZOTTA, A. MURARI, and JET–EFDA CONTRIBUTORS: Mutual interaction<br />

of Faraday rotation and Cotton Mouton phase shift in JET polarimetric measurements, Rev. Sci. Instrum. 81, 10D533(1–4) (2010)<br />

A. ROMANO, D. PACELLA, D. MAZON, F. MURTAS, P. MALARD, L. GABELLIERI, B. TILIA, V. PIERGOTTI, G. CORRADI: Characterization of a<br />

2D soft–x ray tomography camera with <strong>di</strong>scrimination in energy bands, Rev. Sci. Instrum. 81, 10E523(1–3) (2010)<br />

E. GIOVANNOZZI, M. BEURSKENS, M. KEMPENAARS, R. PASQUALOTTO, A. RYDZY and JET–EFDA CONTRIBUTORS: Detection of dust on<br />

JET with the high resolution Thomson scattering systems, Rev. Sci. Instrum. 81, 10E131(1–3) (2010)<br />

G. MONDONICO, B. SEEBER, C. SENATORE, R. FLUKIGER, V. CORATO, G. DE MARZI, L. MUZZI: Improvement of electromechanical<br />

properties of an ITE internal tin Nb 3 Sn wire, J. Appl. Phys. 108, 093906 (2010)<br />

F. BORGOGNONI, D. DEMANGE, L. DORR, S. TOSTI, S. WELTE: Processing test of an upgraded mechanical design for PERMCAT reactor,<br />

Fusion Eng. Des. 85, issue 10–12, 2171–2175 (2010)<br />

C. FIAMOZZI ZIGNANI, V. CORATO, L. MUZZI, A. DELLA CORTE: Numerical simulation of Nb 3 Sn strands performances with ben<strong>di</strong>ng strain<br />

and comparison with experimental measurements, IEEE Trans. Appl. Supercond. 20, 3, 1432–1435 (2010)<br />

O. TUDISCO, C. MAZZOTTA, A. BOTRUGNO, G. MAZZITELLI, M.L. APICELLA, G. APRUZZESE, D. FRIGIONE, L. GABELLIERI, A. ROMANO AND FTU<br />

TEAM: Peaked density profiles and MHD activity on FTU in lithium dominated <strong>di</strong>scharges, Fusion Eng. Des. 85,6, 902–909 (2010)<br />

A. CARDINALI, V. FUSCO: Analytical and numerical stu<strong>di</strong>es of the cold electromagnetic LH wave equation in the mode converzion<br />

regime, J. Physics: Conf. Ser. 260, 012007 (2010)<br />

F. ZONCA, A. BIANCALANI, I. CHAVDAROVSKI, L. CHEN, C. DI TROIA, X. WNG: Kinetic structures of shear Alfvén and acoustic wave spectra<br />

in burning plasmas, J. Physics: Conf. Ser. 260, 012022 (2010)<br />

R. CESARIO, L. AMICUCCI, C. CASTALDO, D. DE ARCANGELIS, M. FERRARI, M. MARINUCCI, F. NAPOLI, E. POLLURA, L. PANACCIONE, A.A.<br />

TUCCILLO, and FTU TEAM: Parametric instability and lower hybrid current drive at plasma densities required for thermonuclear reactors,<br />

J. Physics: Conf. Ser. 260, 012008 (2010)<br />

A. BIANCALANI, LIU CHEN, F. PEGORARO, F. ZONCA: Shear Alfvén wave continuous spectrum within magnetic island, Phys. of Plasmas<br />

17, 122106(1–7) (2010)<br />

V. PERICOLI RIDOLFINI, G. CALABRÒ, E. GIOVANNOZZI, L. PANACCIONE, A.A. TUCCILLO: LHCD efficiency and scattering by density<br />

fluctuations at the plasma edge, Proc. of the 37th EPS Conference on Plasma Physics, ECA Vol. 34A, P5.176 (2010)<br />

G. CALABRÒ, D.C. MCDONALD, M. BEURSKENS, C.F. MAGGI, I. DAY, E. DE LA LUNA, T. EICH, N. FEDORCZAK, O. FORD, E. GIOVANNOZZI, C.<br />

GIROUD, P. GOHIL, M. LENNHOLM, P.J. LOMAS, J. LONNROTH, G.P. MADDISON, I. NUNES, V. PERICOLI RIDOLFINI, F. RYTER, G. SAIBENE, R.<br />

SARTORI, W. STUDHOLME, E. SURREY, I. VOITSEKHOVITCH, K.D. ZASTROW and JET–EFDA CONTRIBUTORS: H–Mode threshold stu<strong>di</strong>es in<br />

helium–4 JET plasmas, Proc. of the 37th EPS Conference on Plasma Physics, ECA Vol. 34A, O5.127 (2010), ISBN: 2–914771–62–2<br />

V. PERICOLI–RIDOLFINI: Increased particle and energy transport induced by LH waves in the tokamak scrape–off layer plasma, Proc. of<br />

the 37th EPS Conference on Plasma Physics, ECA Vol. 34A, P5.177 (2010), ISBN: 2-914771-62-2<br />

M.L. APICELLA, G. APRUZZESE, G. MAZZITELLI, A.G. ALEKSEYEV, A. BOTRUGNO, P. BURATTI, R. DE ANGELIS, H. KROEGLER, V.B.<br />

LAZAREV, S.V. MIRNOV, R. ZAGORSKI: Ra<strong>di</strong>ative layer with a liquid ithium limiter on FTU, Proc. of the 37th EPS Conference on Plasma<br />

Physics, ECA Vol. 34A, P2.114 (2010), ISBN: 2–914771–62–2


publications and events (cont’d.)<br />

progress report<br />

2010<br />

103<br />

G. CALABRO’, E. GIOVANNOZZI, R. RAMOGIDA, F. CRISANTI, C. LABATE, M. MATTEI, P. MICOZZI, G. VLAD: Modelling of FAST equilibrium<br />

configurations by a toroidal multipolar expansion code using Kepler workflows, Proc. of the 37th EPS Conference on Plasma Physics,<br />

ECA Vol. 34A, P4.157 (2010), ISBN: 2–914771–62–2<br />

A. BIERWAGE, L. CHEN, F. ZONCA: Pressure–gra<strong>di</strong>ent–induced Alfvén eigenmodes destabilized by ion temperature gra<strong>di</strong>ent, Proc. of the<br />

37th EPS Conference on Plasma Physics, ECA Vol. 34A, P4.179 (2010), ISBN: 2–914771–62–2<br />

A. JACCHIA, S. CIRANT, F. DE LUCA, P. BURATTI, E. LAZZARO, O. TUDISCO, C. MAZZOTTA, G. CALABRO’ G. RAMOGIDA, C. CIANFARANI,<br />

D. MAROCCO, G. GROSSETTI, G. GRANUCCI, O. D’ARCANGELO, W. BIN and FTU and ECRH TEAM: Density response to modulated EC<br />

heating in FTU tokamak, Proc. of the 37th EPS Conference on Plasma Physics, ECA Vol. 34A, P1.045 (2010), ISBN: 2–914771–62–2<br />

A. BOTRUGNO, P. BURATTI, F. ZONCA: Comparison between BAE observations at FTU and theoretical models, Proc. of the 37th EPS<br />

Conference on Plasma Physics, ECA Vol. 34A, P4.110 (2010), ISBN: 2–914771–62–2<br />

M. GONICHE, Y. BARANOV, P. BONOLI, G. CALABRO’, A. CARDINALI, C. CASTALDO, R. CESARIO, J. DECKER, J. GARCIA, G. GIRUZZI, E.<br />

JOFFRIN, A. HUBBARD, K. KIROV, X. LITAUDON, J. MAILLOUX, R. PARKER: Lower hybrid current drive for the steady state scenario, Plasma<br />

Phys. Control. Fusion 52, 124031 (18pp) (2010)<br />

B. BAIOCCHI, G. CALABRÒ, L. LAURO–TARONI, P. MANTICA, A. CARDINALI, G. CORRIGAN, F. CRISANTI, D. FARINA, L. FIGINI, G. GIRUZZI,<br />

T. JOHNSON, M. MARINUCCI, V. PARAIL: Pre<strong>di</strong>ctive modelling of H–mode and steady–state scenarios in FAST, Proc. of the 37th EPS<br />

Conference on Plasma Physics, ECA Vol. 34A, P1.007 (2010), ISBN: 2–914771–62–2<br />

M. BARUZZO, M. SCHNEIDER, V. BASIUK, A. CARDINALI, M. MARINUCCI, J.F. ARTAUD, O. ASUNTA, T. BOLZONELLA, F. CRISANTI, R.<br />

DUMONT, G. GIRUZZI, F. IMBEAUX, P. MANTICA, M. VALISA, F. ZONCA: First NBI configuration study for FAST proposal, Proc. of the 37th<br />

EPS Conference on Plasma Physics, ECA Vol. 34A, P5.142 (2010), ISBN: 2–914771–62–2<br />

A. BIANCALANI, L. CHEN, F. PEGORARO, F. ZONCA: Continuous spectrum of shear Alfvén waves inside magnetic islands, Proc. of the<br />

37th EPS Conference on Plasma Physics, ECA Vol. 34A, P4.109 (2010), ISBN: 2–914771–62–2<br />

L. FRASSINETTI, M.N.A. BEURSKENS, D.C. MCDONALD, J. HOBIRK, D. WARZOSO, P. BURATTI, F. CRISANTI, C. CHALLIS, E. GIOVANNOZZI, E.<br />

JOFFRIN, P. LOMAS, J. LONNROTH, C. MAGGI, I. NUNES, S. SAARELMA, G. SAIBENE and JET EFDA CONTRIBUTORS: Pedestal confinement in<br />

hybrid versus baseline plasmas in JET, Proc. of the 37th EPS Conference on Plasma Physics, ECA Vol. 34A, P1.1031 (2010)<br />

M. ANGELONE, M. PILLON, R. FACCINI, D. PINCI, W. BALDINI, R. CALABRESE: Silicon photo–multiplier ra<strong>di</strong>ation hardness tests with<br />

a beam controlled neutron source, Nucl. Instrum. Meth. Phys. Res. A 623, 921–926 (2010)<br />

P. BATISTONI, M. ANGELONE, P. CARCONI, U. FISCHER, K. FLEISCHER, K. KONDO, A. KLIX, I. KODELI, D. LEICHTLE, L. PETRIZZI, M. PILLON,<br />

W. POHORECKI, M. SOMMER, A. TRKOV, R. VILLARI. Neutronics experiments on HCPB and HCLL TBM mock–ups in preparation of<br />

nuclear measurements in ITER, Fusion Eng. Des. 85, 1675–1680 (2010)<br />

C. NARDI, L. BETTINALI, M. LABANTI: Long term characterization on uni<strong>di</strong>rectional fiberglass for ITER pre–compression rings, Fusion Eng.<br />

Des. 85, 2241–2244 (2010)<br />

E. VISCA, E. CACCIOTTI, S. LIBERA, A. MANCINI, A. PIZZUTO, S. ROCCELLA, B. RICCARDI, F. ESCOURBIAC, G.P. SANGUINETTI: Manufacturing<br />

and testing of reference samples for ITER <strong>di</strong>vertor acceptance criteria definition, Fusion Eng. Des. 85, 1986–1991 (2010)<br />

T. PINNA, L.C. CADWALLADER, G. CAMBI, S. CIATTAGLIA, S. KNIPE, F. LEUTERER, A. MALIZIA, P. PETERSEN, M.T. PORFIRI, F. SAGOT, S.<br />

SCALES, J. STOBER, J.C. VALLET, T. YAMANISHI: Operating experiences from existing fusion facilities in view of ITER safety and reliability,<br />

Fusion Eng. Des. 85, 1410–1415 (2010)<br />

T. PINNA, G. CAMBI, S. KNIPE and JET–EFDA CONTRIBUTORS: JET operating experience: global analysis of tritium plant failure, Fusion<br />

Eng. Des. 85, 1396–1400 (2010)<br />

G. CAMBI, D.G. CEPRAGA, L. DI PACE, F. DRUYTS, V. MASSAUT: The potential presence and minimisation of plutonium within the irra<strong>di</strong>ated<br />

beryllium in fusion power plants, Fusion Eng. Des. 85, 1139–1142 (2010)<br />

D. LEICHTLE, U. FISCHER, I. KODELI, R.L. PEREL, A. KLIX, P. BATISTONI, R. VILLARI: Sensitivity and uncertainty analyses of the HCLL<br />

mock–up experiment, Fusion Eng. Des. 85, 1724–1727 (2010)<br />

S. NICOLLET, B. LACROIX, L. ZANI, P. HERTOUT, CH. PORTAFAIX, R. VILLARI: Development of an extended thermo-hydraulic simulation<br />

tool for fusion magnet design study – Application to the initial versions of JT–60SA TF coils layout, Cryogenic 50,1, 18–27 (2010)<br />

A. KLIX, P. BATISTONI, R. BOTTGER, D. LEBRUN-GRANDIE, U. FISCHER, J. HENNIGER, D. LEICHTLE, R. VILLARI: Measurement and analysis<br />

of neutron flux spectra in a neutronics mock–up of the HCLL test blanket module, Fusion Eng. Des. 85, 1803–1806 (2010)<br />

A. EKEDAHL, L. DELPECH, M. GONICHE, D. GUILHEM, J. HILLAIRET, M. PREYNAS, P.K. SHARMA, J. ACHARD, Y.S. BAE, X. BAI, C. BALORIN,<br />

Y. BARANOV, V. BASIUK, A.BÉCOULET, J. BELO, G. BERGER-BY, S. BRÉMOND, C. CASTALDO, S. CECCUZZI, R. CESARIO, E. CORBEL, X.<br />

COURTOIS, J. DECKER, E. DELMAS, X. DING, D. DOUAI, C. GOLETTO, J.P. GUNN, P. HERTOUT, G.T. HOANG, F. IMBEAUX, K.K. KIROV, X.


104<br />

progress report<br />

2010<br />

LITAUDON, R. MAGNE, J. MAILLOUX, D. MAZON, F. MIRIZZI, P. MOLLARD, P. MOREAU, T. OOSAKO, V. PETRZILKA, Y. PEYSSON, S. POLI, M.<br />

PROU, F. SAINT–LAURENT, F. SAMAILLE, B. SAOUTIC: Val<strong>di</strong>ation of the ITER–relevant passive–active–multijunction LHCD laucher on long<br />

pulses in Tore Supra, Nucl. Fusion 50, 112002(5pp) (2010)<br />

A. MILOVANOV: Self–organized criticality with a fishbone–like instability cycle, Europhys. Lett. 89, 60004 (2010)<br />

G. MAZZITELLI, M.L. APICELLA, G. APRUZZESE, R. DE ANGELIS, D. FRIGIONE, E. GIOVANNOZZI, L. GABELLIERI, G. GRANUCCI, C.<br />

MAZZOTTA, M. MARINUCCI, A. ROMANO, O. TUDISCO, FTU TEAM and ECRH TEAM: Review of FTU results with the liquid lithium limiter,<br />

Fusion Eng. Des. 85, 6, 902–909 (2010)<br />

F. CRISANTI, R. ALBANESE, F. ARTAUD, B. BAIOCCHI, M. BARUZZO, V. BASIUK, A. BIERWAGE, R. BILATO, T. BOLZONELLA, M. BRAMBILLA, S.<br />

BRIGUGLIO, G. CALABRO’, A. CARDINALI, G. CORRIGAN, A. CUCCHIARO, C. DI TROIA, D. FARINA, L. FIGINI, G. FOGACCIA, G. GIRUZZI, G.<br />

GRANUCCI, F. IMBEAUX, T. JOHNSON, L. LAURO TARONI, R. MAGGIORA, P. MANTICA, D. MILANESIO, V. PARAIL, V. PERICOLI–RIDOLFINI, A.<br />

PIZZUTO, S. PODDA, G. RAMOGIDA, M. SANTINELLI, M. SCHNEIDER, A. TUCCILLO, M. VALISA, R. VILLARI, B. VIOLA, G. VLAD, X. WANG, F.<br />

ZONCA: Scenario development for FAST in the view of ITER and DEMO, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 - Paper<br />

FTP/2–4 (2010) online at: http://www-pub.iaea.org/mtcd/meetings/ cn180_papers.asp<br />

A. CARDINALI, M. BARUZZO, C. DI TROIA, M. MARINUCCI, A. BIERWAGE, G. BREYIANNIS, S. BRIGUGLIO, G. FOGACCIA, G. VLAD, X. WANG,<br />

F. ZONCA, V. BASIUK, R. BILATO, M. BRAMBILLA, F. IMBEAUX, S. PODDA, M. SCHNEIDER: Energetic particle physics in FAST H–mode<br />

scenario with combined NNBI and ICRH, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 – Paper THW/P7-04 (2010) online<br />

at: http://www–pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

P. MANTICA, B. BAIOCCHI, G. CALABRO’, L. LAURO TARONI,, O. ASUNTA, M. BARUZZO, A. CARDINALI, G. CORRIGAN, F. CRISANTI, D.<br />

FARINA, L. FIGINI, G. GIRUZZI, F. IMBEAUX, T. JOHNSON, M. MARINUCCI, V. PARAIL, A. SALMI, M. SCHNEIDER, M. VALISA: Physics based<br />

modelling of H–mode and advanced tokamak scenarios for FAST: analysis of the role of rotation in pre<strong>di</strong>cting core transport in future<br />

machines, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper THC/P2-05 (2010) online at:<br />

http://www–pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

M. TARDOCCHI, A. BRUSCHI, D. MAROCCO, N. NOCENTE, G. CALABRO’, A. CARDINALI, F. CRISANTI, B. ESPOSITO, L. FIGINI, G. GORINI,<br />

G. GROSSETTI, G. GROSSO, M. LONTANO, S. NOVAK, F. ORSITTO, U. TARTARI, O TUDISCO: Production and <strong>di</strong>agnosis of energetic particle<br />

in FAST, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXW/P7–26 (2010) online at: http://www–pub.iaea.org/mtcd/<br />

meetings/cn180_papers.asp<br />

G. MAZZITELLI, M.L. APICELLA, D. FRIGIONE, G. MADDALUNO, M. MARINUCCI, C. MAZZOTTA, V. PERICOLI–RIDOLFINI, M. ROMANELLI, G.<br />

SZEPESI, O. TUDISCO AND FTU TEAM: FTU results with the liquid lithium limiter, Proc. of the 23rd IAEA Fusion Energy Conference, CN-<br />

180 -Paper EXC/6–3 (2010) online at: http://www–pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

B. ESPOSITO, G. GRANUCCI, M. MARASCHEK, S. NOWAK, A. GUDE, V. IGOCHINE, R. MCDERMOTT, F. POLI, J. STOBER, W. SUTTROP, W.<br />

TREUTTERER, H. ZOHM AND ASDEX UPGRADE TEAM: Avoidance of <strong>di</strong>scruption at high ‚β n in ASDEX Upgrade with off–axis ECRH, Proc.<br />

of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXW/10–2Ra (2010) online at: http://www-pub.iaea.org/mtcd/<br />

meetings/cn180_papers.asp<br />

R. DE ANGELIS, F. ORSITTO, M. BARUZZO, P. BURATTI, B. ALPER, L. BARRERA, A. BOTRUGNO, M. BRIX, K. CROMBE’, L. FIGINI, A. FONSECA, C.<br />

GIROUD, N. HAWKES, D. HOWELL, E. DE LA LUNA, V. PERICOLI-RIDOLFINI, E. RACHLEW, O. TUDISCO AND JET–EFDA CONTRIBUTORS:<br />

Determination of q profiles in JET by consistency of motional stark effect and MHD mode localization, Proc. of the 23rd IAEA Fusion Energy<br />

Conference, CN-180 - Paper EXS/P2-03 (2010) online at: http://www-pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

R. DE ANGELIS, F. ORSITTO, M. BARUZZO, P. BURATTI, B. ALPER, L. BARRERA, A. BOTRUGNO, M. BRIX, K. CROMBE’, L. FIGINI, A.<br />

FONSECA, C. GIROUD, N. HAWKES, D. HOWELL, E. DE LA LUNA, V. PERICOLI-RIDOLFINI, E. RACHLEW, O. TUDISCO AND JET–EFDA<br />

CONTRIBUTORS: Particle deposition, transport and fuelling in pellet injection experiments at JET, Proc. of the 23rd IAEA Fusion Energy<br />

Conference, CN-180 - Paper EXC/P4-05 (2010) online at: http://www-pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

P. BURATTI, M. BARUZZO, R.J. BUTTERY, C.D. CHALLIS, I.T. CHAPMAN, F. CRISANTI, L. FIGINI, M. GRYAZNEVICH, T.C. HENDER, D.F.<br />

HOWELL, H. HAN, E. JOFFRIN, J. HOBIRK, F. IMBEAUX, O.J. KWON, X. LITAUDON,J. MAILLOUX AND JET–EFDA CONTRIBUTORS: Kink<br />

instabilities in high–beta JET advanced scenarios, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXS/P5-02 (2010)<br />

online at: http://www–pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

R. CESARIO, L. AMICUCCI, M.L. APICELLA, G. CALABRO’, A. CARDINALI, C. CASTALDO, C. CIANFARANI, D. FRIGIONE, M. MAZZITELLI, C.<br />

MAZZOTTA, L. PANACCIONE, V. PERICOLI-RIDOLFINI, A.A. TUCCILLO, O. TUDISCO AND FTU TEAM: Lower hybrid current drive at densities<br />

required for thermonuclear reactors, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXW/P7–02 (2010) online at:<br />

http://www–pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

A.A. TUCCILLO ON BEHALF OF FTU TEAM AND A. ALEXEYEV, L. AMICUCCI, A. BIANCALANI, A. BIERWAGE, G. BREYANNIS, I.<br />

CHAVDAROVSKI, L. CHEN, F. DE LUCA, Z.O. GUIMARAES–FILHO, A. JACCHIA, E. LAZZARO, F. PEGORRO, M. ROMANELLI, X. WANG:


publications and events (cont’d.)<br />

progress report<br />

2010<br />

105<br />

Overview of the FTU results, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper OV/4-2 (2010) online at:<br />

http://www–pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

G. GRANUCCI, G. RAMPONI, G. CALABRO’, F. CRISANTI, G. RAMOGIDA, W. BIN, A. BOTRUGNO, P. BURATTI, O. D’ARCANGELO, D.<br />

FRIGIONE, G. PUCELLA, A. ROMANO, O. TUDISCO, AND FTU TEAM: Plasma start–up results with EC assisted breakdown on FTU, Proc.<br />

of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXW/P2–03 (2010) online at: http://www–pub.iaea.org/mtcd/<br />

meetings/cn180_papers.asp<br />

D.C. MCDONALD, G. CALABRO’, M. BEURSKENS, I. DAY, E, DE LA LUNA, T. EICH, N. FEDORCZAC, O. FORD, W. FUNDAMENSKI,<br />

C. GIROUD, P. GOHIL, M. LENNHOLM, J. LONNROTH, P.J. LOMAS, G.P. MADDISON, C.F. MAGGI, I. NUNES, G. SAIBENE, R. SARTORI, W.<br />

STUDHOLME, E. SURREY, I. VOITSEKOVITCH, K.D. ZATROW AND JET–EFDA CONTRIBUTORS: JET helium–4 ELMy H–mode stu<strong>di</strong>es, Proc.<br />

of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXC/2–4rb (2010) online at: http://www–pub.iaea.org/mtcd/<br />

meetings/cn180_papers.asp<br />

M. BARUZZO, B. ALPER,T. BOLZONELLA, M. BRIX, P. BURATTI, C.D. CHALLIS, F. CRISANTI, E. DE LA LUNA, P.C. DE VRIES, C. GIROUD, N.C.<br />

HAWKES, D.F. HOWELL, F. IMBEAUX, E. JOFFRIN, H.R. KOSLOWSKI, X. LITAUDON, J. MAILLOUX, A.C.C. SIPS, O. TUDISCO AND JET–EFDA<br />

CONTRIBUTORS: Neoclassical tearing mode (NTM) magnetic spectrum and magnetic coupling in JET tokamak, Plasma Phys. Control.<br />

Fusion 52, 075001 (18pp) (2010)<br />

P. MAGET, H. LUTJENS, R. COELHO, B. ALPER, M. BRIX, P. BURATTI, R.J. BUTTERY, E. DE LA LUNA, N. HAWKES, G.T.A. HUYSMANS, J.<br />

JENKINS, C.D. CHALLIS, C. GIROUD, X. LITAUDON, J. MAILLOUX, M. OTTAVIANI AND JET–EFDA CONTRIBUTORS: Modelling of (2,1) NTM<br />

threshold in JET advanced scenarios, Nucl. Fusion 50, 045004 (16pp) (2010)<br />

E. JOFFRIN, C.D. CHALLIS, J. CITRIN, J. GARCIA, J. HOBIRK, I. JENKINS, J. LONNROTH, D.C. MCDONALD, P. MAGET, P. MANTICA, M.<br />

BEURSKENS, M. BRIX, P. BURATTI, F. CRISANTI, L. FRASSINETTI, C. GIROUD, F. IMBEAUX, M. PIOVESAN, F. RIMINI, G. SERGIENKO, A.C.C.<br />

SIPS, T. TALA, I. VOITSEKOVITCH and JET–EFDA CONTRIBUTORS: High confinement hybrid scenario in JET and its significance for ITER,<br />

Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXC/1_1 (2010) online at:<br />

http://www–pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

J. MAILLOUX, X. LITAUDON, P.C. DE VRIES, J. GARCIA, I. JENKINS, B. ALPER, YU.BARANOV, M. BARUZZO, M. BEURSKENS, M. BRIX, P.<br />

BURATTI, G. CALABRÒ, R. CESARIO, C.D. CHALLIS, K. CROMBE, O. FORD, D. FRIGIONE, C. GIROUD, M. GONICHE, N. HAWKES, D.<br />

HOWELL, P. JACQUET, E. JOFFRIN, V. KIPTILY, K.K. KIROV, P. MAGET, D.C. MCDONALD, V. PERICOLI–RIDOLFINI, V. PLYUSIN, F. RIMINI, M.<br />

SCHNEIDER, S. SHARAPOV, C. SOZZI, I. VOITSEKOVITCH, L. ZABEO and JET–EFDA CONTRIBUTORS: Towards a steasy-state scenario with<br />

ITER <strong>di</strong>mensionless parameters in JET, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXC/1_4 (2010) online at:<br />

http://www-pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

P. MAGET, H. LUTJENS, B. ALPER, M. BARUZZO, M. BRIX, P. BURATTI, R.J. BUTTERY, C. CHALLIS, R. COELHO, E. DE LA LUNA, C. GIROUD,<br />

N. HAWKES, G.T.A. HUYSMANS, I. JENKINS, X. LITAUDON, J. MAILLOUX, N. MELLET, D. MESHCHERIAKOV, M. OTTAVIANI, AND JET–EFDA<br />

CONTRIBUTORS: Non linear MHD modelling of NTMs in JET advanced scenarios, Proc. of the 23rd IAEA Fusion Energy Conference, CN-<br />

180 -Paper EXC/P5–09 (2010) online at: http://www-pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

P. MANTICA, C. ANGIONI, B. BAIOCCHI, C. CHALLIS, J. CITRIN, G. COLYER, A.C.A. FIGUEIREDO, L. FRASSINETTI, E. JOFFRIN, T. JOHNSON, E.<br />

LERCHE, A.G. PEETERS, A. SALMI, D. STRINTZI, T. TALA, M. TSALAS, D. VAN EESTER, P.C. DE VRIES, J. WEILAND, M. BARUZZO, M.N.A.<br />

BEURSKENS, J.P.S. BIZARRO, P. BURATTI, F. CRISANTI, X. GARBET, C. GIROUD, N. HAWKES, J. HOBIRK, F. IMBEAUX, J. MAILLOUX, V. NAULIN,<br />

C. SOZZI, G. STAEBLER, T.W. VERSLOOT AND JET–EFDA CONTRIBUTORS: A key to improved ion core confinement in the JET tokamak: ion<br />

stiffness mitigation due to combined plasma rotation and low magnetic shear, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -<br />

Paper EXC/9-2 (2010) online at: http://www-pub.iaea.org/mtcd/ meetings/cn180_papers.asp<br />

P.A. POLITZER, C.D. CHALLIS, E. JOFFRIN, T.C. LUCE, M. BEURSKENS, P. BURATTI, F. CRISANTI, J.C. DEBOO, J.R. FERRON, C. GIROUD,<br />

J. HOBIRK, C.T. HOLCOMB, A.W. HYATT, F. IMBEAUX, R.J. JAYAKUMAR, I. JENKINS, J.E. KINSEY, R.J. LA HAYE, D.C. MCDONALD, C.C.<br />

PETTY, F. TURCO, M.R. WADE AND JET–EFDA CONTRIBUTORS: Understan<strong>di</strong>ng confinement in advaced inductive scenario plasmas -<br />

dependence on gyrora<strong>di</strong>us and rotation, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXC/P2–06 (2010) online at:<br />

http://www–pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

M.P. GRAYAZNEVICH, Y.Q. LIU, T.C. HENDER, D.F. HOWELL, I.T. CHAPMAN, C.D. CHALLIS, S.P. PINCHES, E. JOFFRIN, H.R. KOSLOWSKI, P.<br />

BURATTI, E. SOLANO AND JET–EFDA CONTRIBUTORS: Determination of plasma stability using resonant field amplification in JET, Proc.<br />

of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper EXC/P5–06 (2010) online at: http://www-pub.iaea.org/mtcd/<br />

meetings/cn180_papers.asp<br />

M. ANGELONE, G. AIELLI, S. ALMAVIVA, R. CARDARELI, D. LATTANZI, M. MARINELLI, E. MILANI, M. PILLON, G. PRESTOPINO, R.<br />

SANTONICO, C. VERONA, G. VERONA RINATI: Neutron spectroscopy by means of artificial <strong>di</strong>amond detectors using a remote read out<br />

scheme, IEEE Trans. Nucl. Sci. 57, 6, 3655–3660 (2010)


106<br />

progress report<br />

2010<br />

S. VENTICINQUE, R. AVERSA, B. DI MARTINO, R. DONINI, S. BRIGUGLIO, G. VLAD: Management of high performance scientific applications<br />

using mobile agents based services, Scalable Computing: Practice and Experience 11, 2, 149–159 (2010)<br />

C. CASTALDO, S. RATYNSKAIA, M. DE ANGELI, U. DE ANGELIS: On the feasibility of electro–optical detection of dust–impact ionization in<br />

tokamaks, Plasma Phys. Control. Fusion 52, 105003 (6pp) (2010)<br />

S. RATYNSKAIA, M. DE ANGELI, E. LAZZARO, C. MARMOLINO, U. DE ANGELIS, C. CASTALDO, A. CREMONA, L. LAGUARDIA, G. GERVASINI,<br />

G. GROSSO: Plasma fluctuation spectra as a <strong>di</strong>agnostic tool for submicron dust, Phys. of Plasmas 17, 043703 (2010)<br />

X. WANG, S. BRIGUGLIO, G. FOGACCIA, G. VLAD, C. DI TROIA, F. ZONCA, L. CHEN, A. BIERWAGE, H. ZHANG: Kinetic thermal ions effects<br />

on Alfvénic fluctuations in tokamak plasmas, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper THW/2–4Ra (2010) online<br />

at: http://www–pub.iaea.org/mtcd/meetings/cn180_papers.asp<br />

L. CHEN, W. DENG, Z. LIN, D. SPONG, G.Y. SUN, X. WANG, X.Q.XU, H.S. ZHANG, W.L. ZHANG, A. BIERWAGE, S. BRIGUGLIO, I. HOLOD, G.<br />

VLAD, Y. XIAO, F. ZONCA: Verification of gyrokinetic particle simulation of Alfvén eigenmodes excited by external antenna and by fast<br />

ions, Proc. of the 23rd IAEA Fusion Energy Conference, CN-180 -Paper THW/P7–25 (2010) online at: http://www–pub.iaea.org/mtcd/<br />

meetings/cn180_papers.asp<br />

ZHIYONG QUI, F. ZONCA, L. CHEN: Kinetic theories of geodesic acoustic mode in toroidal plasmas, Proc. of the 23rd IAEA Fusion Energy<br />

Conference, CN-180 - Paper THW/P8–01 (2010) online at: http://www–pub.iaea.org/mtcd/meetings/ cn180_papers.asp<br />

A. MURARI, M. ANGELONE, G. BONHEURE, E. CECIL, T. CRACIUNESCU, D. DARROW, T. EDLINGTON, G. ERICSSON, M. GATU-JOHNSON,<br />

G. GORINI, C. HELLESEN, V. KIPTILY, J. MLYNAR, C. PEREZ VON THUN, M. PILLON, S. POPOVICHEV, B. SYME, M. TARDOCCHI, V.L. ZOITA<br />

AND EFDA–JET CONTRIBUTORS: New developments in the <strong>di</strong>agnostics for the fusion products on JET preparation for ITER (invited<br />

paper), Rev. Sci. Instrum. 81, 10E136(1–8) (2010)<br />

S. ALMAVIVA, M. MARINELLI, E. MILANI, G. PRESTOPINO, A. TUCCIARONE, C. VERONA, G. VERONA–RINATI, M. ANGELONE, M. PILLON, I.<br />

DOLBNYA, K. SAWHNEY, N. TARTONI: Chemical vopor deposition <strong>di</strong>amond based multilayered ra<strong>di</strong>ation detector: physical analysis of<br />

detection properties, J. Appl. Phys. 107, 014511(1–7) (2010)<br />

S. ALMAVIVA, MARCO MARINELI, E. MILANI, G. PRESTOPINO, A. TUCCIARONE, C. VERONA, G. VERONA–RINATI, M. ANGELONE, M. PILLON:<br />

Extreme UV single crystal <strong>di</strong>amond Schottky photo<strong>di</strong>ode in planar and transverse configuration, Diamond & Rel. Mat. 19, 78–82 (2010)<br />

S. SANDRI, A. CONIGLIO, A. DANIELE, M. D’ARIENZO, M. PILLON: Ra<strong>di</strong>ation shiel<strong>di</strong>ng for the ITER neutral beam test facility, Procee<strong>di</strong>ngs<br />

of the 12th Congress of the Ra<strong>di</strong>ation Protection Association (IRPA12), Procee<strong>di</strong>ngs Series STI/PUB/1460 Companion CD (2010)<br />

K. SHINOHARA, T. KURKI-SUONIO, D. SPONG, O. ASUNTA, K. TANI, E. STRUMBERGER, S. BRIGUGLIO, S. GUNTER, T. KOSKELA, G.<br />

KRAMER, S. PUTVINSKI, K. HAMAMATSU, ITPA TOPICAL GROUP ON ENERGETIC PARTICLES: 3D effect of ferromagnetic materials on<br />

alpha particle power loads on first wall structures and equilibrium on ITER, Proc. of the 23rd IAEA Fusion Energy Conference, CN–180<br />

– Paper ITR/P1–36 (2010) online at: http://www–pub.iaea.org/mtcd/meetings/ cn180_papers.asp<br />

P. COSTA, C. NERI, M. SPAGNOLO, G. FALCINELLI, F. MICCHETTI: A software platform for the optimization of IVVS viewing performances,<br />

Procee<strong>di</strong>ng of the 2010 EnginSoft International Conference, p.1–19 (2010)<br />

R. VITELLI, L. BONCAGNI, F. MECOCCI, S. PODDA, V. VITALE, L. ZACCARIAN: An anti–windup-based solution for the low current<br />

nonlinearity compensation on the FTU horizontal position controller, Procee<strong>di</strong>ngs of the 49th IEEE Conference on Decision and Control,<br />

Atlanta 2010, Article n. 5717837, pp. 2735–2740 (2011) - ISBN 978–142447745–6<br />

G. VARANO, L. BONCAGNI, S. GALEANI, G. GRANUCCI, V. VITALE, L. ZACCARIAN: Results on plasma position and elongation regulation<br />

at FTU using dynamic input allocation, Procee<strong>di</strong>ngs of the 49th IEEE Conference on Decision and Control, Atlanta 2010, Article no<br />

5717468, pp 2753–2758 (2011) – ISBN 978–142447745–6<br />

Articles in course of publication<br />

R. CESARIO, L. AMICUCCI, C. CASTALDO, M. DEMPENAARS, J. JACHMICH, J. MAILLOUX, O. TUDISCO AND EFDA-JET CONTRIBUTORS:<br />

Plasma edge density and lower hybrid current drive in JET (Joint European Torus), Plasma Phys. Control. Fusion<br />

R. VITELLI, L. BONCAGNI, F. MECOCCI, S. PODDA, V. VITALE, L. ZACCARIAN: An anti–windup–based solution for the low current<br />

nonlinearity compensation on the FTU horizontal position controller, Proc. 49th IEEE Conference on Decision and Control<br />

G. VARANO, L. BONCAGNI, S. GALEANI, G. GRANUCCI, V. VITALE, L. ZACCARIAN: Plasma position and elongation regulation at FTU using<br />

dynamic allocation, Proc. 49th IEEE Conference on Decision and Control<br />

R. VITELLI, L. BONCAGNI, F. MECOCCI, S. PODDA, V. VITALE, L. ZACCARIAN: An anti–windup–based solution for the low current<br />

nonlinearity compensation on the FTU horizontal position controller, IEEE Trans. Control Syst. Technol.


publications and events (cont’d.)<br />

progress report<br />

2010<br />

107<br />

L. BONCAGNI, Y. SADEGHI, D. CARNEVALE, G. MAZZITELLI, A. NETO, D. PUCCI, F. SARTORI, S. SINIBALDI, V. VITALE, R. VITELLI, L.<br />

ZACCARIAN, S. MONACO, G. ZAMBORLINI: First steps in the FTU migration towards a modular and <strong>di</strong>stributed real–time control<br />

architecture based on MARTe, IEEE Trans. Nucl. Sci.<br />

L. BONCAGNI, A. BARBALACE, Y. SADEGHI, M. POMPEI, L. ZACCARIAN, F. SARTORI: Switched ethernet in synchronized <strong>di</strong>stributed control<br />

systems using RTnet, IEEE Trans. Nucl. Sci.<br />

C. NERI, P. COSTA, M. FERRI DE COLLIBUS, M. FLOREAN, G. MUGNAINI, M. PILLON, F. POLLASTRONE, P. ROSSI: ITER in vessel viewing<br />

system design and assessment activities, Fusion Eng. Des.<br />

E. VISCA, E. CACCIOTTI, A. KOMAROV, S. LIBERA, N. LITUNOVSKY, A. MAKHANKOV, A. MANCINI, M. MEROLA, A. PIZZUTO, B. RICCARDI, S. ROCCELLA:<br />

Manufacturing, testing and post–test examination of ITER <strong>di</strong>vertor vertical target W small scale mock–ups, Fusion Eng. Des.<br />

G. VARANO, L. BONCAGNI, S. GALEANI, G. GRANUCCI, V. VITALE, L. ZACCARIAN: Plasma position and elongation regulation at FTU using<br />

dynamic allocation, IEEE Trans. Control Syst. Technol.<br />

F. MIRIZZI, S. CECCUZZI, S. MESCHINO, J.F. ARTAUD, J.H. BELO, G. BERGER-BY, J.M. BERNARD, A. CARDINALI, C. CASTALDO, R. CESARIO, J.<br />

DECKER, L. DELPECH, A. EKEDAHL, J. GARCIA, P. GARIBALDI, M. GONICHE, D. GUILHEM, G.T. HOANG, J. HUA, Q.Y. HUANG, J. HILLAIRET, F.<br />

IMBEAUX, F. KAZARIAN, S.H. KIM, X. LITAUDON, R. MAGGIORA, R. MAGNE, L. MARFISI, D. MILANESIO, W. NAMKUNG, L. PAJEWSKI, L.<br />

PANACCIONE, Y. PEYSSON, P.K. SHARMA, G. SCHETTINI, M. SCHNEIDER, A.A. TUCCILLO, O. TUDISCO, G. VECCHI, R. VILLARI, K. VULLIEZ:<br />

Contribution to the design of the main transmission line for the ITER relevant LHCD system, Fusion Eng. Des.<br />

S. GAUDIO, G. DE MARZI, G. CELENTANO, A. AUGIERI, V. GALLUZZI, A. MANCINI, A. RUFOLONI, A. VANNOZZI, A. DELLA CORTE, U.<br />

GAMBARDELLA, A. SAGGESE, J.J. JIANG, J. WEISS, E. HELLSTROM, D. LARBALESTIER: The effect of doping on the magnetic properties<br />

in Ba(Fe 1-x Cox) 2 As 2 polycristalline samples, IEEE Trans. Appl. Supercond.<br />

V. CORATO, L. MUZZI, U. BESI VETRELLA, C. FIAMOZZI ZIGNANI, A. DELLA CORTE: Mapping of the transversal resistivity matrix measured<br />

on NbTi and Nb 3 Sn superconducting strands, IEEE Trans. Appl. Supercond.<br />

A. DI ZENOBIO, A. DELLA CORTE, L. MUZZI, G.M. POLLI, L. RECCIA,S. TURTU’, F. CRISANTI, A. CUCCHIARO, A. PIZZUTO, R. VILLARI: FAST:<br />

feasibility analysis for a completely superconducting magnet system, IEEE Trans. Appl. Supercond.<br />

C. FIAMOZZI ZIGNANI, L. MUZZI, S. TURTU’, A. DELLA CORTE: The effect of strand ben<strong>di</strong>ng on the voltage-current characteristics of<br />

Nb 3 Sn cable–in–conduit conductors, IEEE Trans. Appl. Supercond.<br />

A. MANCINI, G. CELENTANO, A. VANNOZZI, V. GALLUZZI, A. RUFOLONI, A. AUGIERI, S. GAUDIO, A.A. ANGRISANI, I. COLANTONI, I. DAVOLI:<br />

The oxidation behaviour at the Ni–W and CeO 2 interface with and without Pd over layer, IEEE Trans. Appl. Supercond.<br />

L. MUZZI, G. DE MARZI, U. BESI VETRELLA, C. FIAMOZZI ZIGNANI, V. CORATO, A. RUFOLONI, A. DELLA CORTE: Test results of a NbTi wire<br />

for the ITER PF 2–5 magnets: a validation of the 2–pinning components model, IEEE Trans. Appl. Supercond.<br />

G.M. POLLI, L. AFFINITO, A. DELLA CORTE: Heat exchanger design for the 30 kA gas cooled current leads in the <strong>ENEA</strong> 12 T CICC facility,<br />

IEEE Trans. Appl. Supercond.<br />

L. RECCIA, S. TURTU’, G.M. POLLI, L. AFFINITO, F. MAIERNA, A. DELLA CORTE, P. DECOOL, A. TORRE, H. CLOEZ, A. VOSTNER, A. DEVRED, D.<br />

BASSETTE, T. BOUTBOUL: Preparation of PF1/6 and PF2 conductor performance qualification sample, IEEE Trans. Appl. Supercond.<br />

S. TURTU’, L. MUZZI, C. FIAMOZZI ZIGNANI, V. CORATO, A. DELLA CORTE, A. DI ZENOBIO, L. RECCIA: Role of the cross–section geometry<br />

in rectangular Nb 3 Sn CICC performance, IEEE Trans. Appl. Supercond.<br />

A. VANNOZZI, V. GALLUZZI, A. MANCINI, A. RUFOLONI, A. AUGIERI, A.A. ANGRISANI, L. CIONTEA, Y. THALMAIER, T. PETRISOR, G. CELENTANO: Study<br />

of MgO–based buffer layer architecture for the development of Ni–Cu–based RABiTS YBCO coated conductor, IEEE Trans. Appl. Supercond.<br />

A. COLETTI, O. BAULAIGUE, P. CARA, R. COLETTI, A. FERRO, E. GAIO, M. MATSUKAWA, L. NOVELLO, M. SANTINELLI, K. SHIMADA, F.<br />

STARACE, T. TERAKADO, K. YAMAUCHI: JT–60SA power supply system, Fusion Eng. Des.<br />

P. ROSSI, M. CAPOBIANCHI, F. CRESCENZI, A. MASSIMI, G. MUGNAINI, C. NARDI, A. PIZZUTO, L. BETTINALI, J. KNASTER, H. RAJAINMAKI,<br />

D. EVANS: Ultimate tensile strength testing campaign on ITER pre–compression ring mock–ups, Fusion Eng. Des.<br />

F. CRESCENZI, F. MARINI, C. NARDI, A. PIZZUTO, P. ROSSI, L. VERDINI, H. RAJAINMAKI, J. KNASTER, L. BETTINALI: Mechanical<br />

characterization of glass fibre–epoxy composite material for ITER pre–compression rings, Fusion Eng. Des.<br />

S. CECCUZZI, S. MESCHINO, F. MIRIZZI, J.F. ARTAUD, Y.S. BAE, J. BELO, G. BERGER-BY, J.M. BERNARD, PH. CARA, A. CARDINALI, C. CASTALDO, R.<br />

CESARIO J. DECKER, L. DELPECH, A. EKEDAHL, J. GARCIA, P. GARIBALDI, M. GONICHE, D. GUILHEM, J. HILLAIRET, G.T. HOANG, Q.Y. HUANG, F.<br />

IMBEAUX, H. JIA, S.H. KIM, Y. LAUSENAZ, R. MAGGIORA, R. MAGNE, L. MARFISI, D. MILANESIO, W. NAMKUNG, L. PAJEWSKI, L. PANACCIONE, Y.<br />

PEYSSON, A. SAILLE, G. SCHETTINI, M. SCHNEIDER, P.K. SHARMA, A.A. TUCCILLO, O. TUDISCO, G. VECCHI, R. VILLARI, K. VULLIEZ, Y. WU, Q. ZENG:<br />

Mode filters for oversized transmission lines, Fusion Eng. Des.


108<br />

progress report<br />

2010<br />

R. VILLARI, L. PETRIZZI, G. BROLATTI, E. DALY, M. LOUGHLIN, A. MARTIN, F. MORO, E. POLUNOVSKY: Three–<strong>di</strong>mensional neutronic<br />

analysis of the ITER in–vessel coils, Fusion Eng. Des.<br />

S. TOSTI, C. RIZZELLO, F. BORGOGNONI, N. GHIRELLI, A. SANTUCCI: Design of Pd-based membrane reactor for gas detritiation, Fusion Eng. Des.<br />

S. CECCUZZI, S. MESCHINO, F. MIRIZZI, G. SCHETTINI: Mode filters for oversized corrugated rectangular vaweguide, Proc. of the XVIII<br />

Riunione Nazionale <strong>di</strong> Elettromagnetisco (RiNEm 2010) e 1^ Conferenza Nazionale della Commissione URSI B<br />

F. MORO, B. ESPOSITO, D. MAROCCO, R. VILLARI, L. PETRIZZI, E. ANDERSSON SUNDEN, S. CONROY, G. ERICSSON, M. GATU JOHNSON, M. DAPENA:<br />

Neutronic calculations in support of the design of the ITER high resolution neutron spectrometer, Fusion Eng. Des.<br />

U. FISCHER, D. GROBE, F. MORO, P. PERESLAVTSEV, R. VILLARI, L. PETRIZZI, V. WEBER: Integral approach for neutronics analyses of the<br />

European test blanket modules in ITER, Fusion Eng. Des.<br />

M. DAPENA, L. PETRIZZI, F. MORO: Preliminary neutronic analyses of ITER high resolution Neutron spectrometer collimator, Fusion Eng. Des.<br />

G. CALABRO’, V. COCILOVO, F. CRISANTI, A. CUCCHIARO, R. MAZZUCA, A. PIZZUTO, G. RAMOGIDA, C. RITA, Y. SADEGHI: Active toroidal<br />

field ripple reduction system in FAST, Fusion Eng. Des.<br />

A. CUCCHIARO, G. BROLATTI, G. CALABRO’, V. COCILOVO, P. FROSI, F. CRESCENZI, F. CRISANTI, G. MADDALUNO, V. PERICOLI-RIDOLFINI, A. PIZZUTO,<br />

C. RITA, G. RAMOGIDA, S. ROCCELLA, P. ROSSI: Engineering evolution of the FAST machine, Fusion Eng. Des.<br />

F. CRISANTI, A. CUCCHIARO, R. ALBANESE, G. ARTASERSE, M. BARUZZO, T. BOLZONELLA, G. BROLATTI, G. CALABRO’, F. CRESCENZI, R.<br />

COLETTI, P. COSTA, A. DELLA CORTE, A. DI ZENOBIO, P. FROSI, L. LAURO TARONI, G. MADDALUNO, D. MARCUZZI, F. MAVIGLIA, L. MUZZI, V.<br />

PERICOLI-RIDOLFINI, A. PIZZUTO, G. POLLI, G. RAMOGIDA, L. RECCIA, V. RIGATO, C. RITA, S. ROCCELLA, M. SANTINELLI, P. SONATO, S. TURTU’,<br />

M. VALISA, B. VIOLA: FAST: a European ITER satellite experiment in the view of DEMO, Fusion Eng. Des.<br />

G. POLLI, A. DELLA CORTE, A. DI ZENOBIO, L. MUZZI, L. RECCIA, S. TURTU’, G. BROLATTI, F. CRISANTI, A. CUCCHIARO, A. PIZZUTO, R. VILLARI: A<br />

thermo–hydraulic analysis of the superconducting proposal for the TF magnet system of FAST, Fusion Eng. Des.<br />

V. PERICOLI–RIDOLFINI, R. ZAGORSKI, B. VIOLA, G. CALABRO’, G. CORRIGAN, F. CRISANTI, G. MADDALUNO, L. LAURO TARONI:<br />

Simulations of the SOL plasma for FAST, a proposed ITER satellite tokamak, Fusion Eng. Des.<br />

F. MAVIGLIA, G, ARTASERSE, R. ALBANESE, G. CALABRO’, F. CRISANTI, A. PIRONTI, A. PIZZUTO, G. RAMOGIDA: Poloidal field circuits<br />

sensitivity stu<strong>di</strong>es and shape control in FAST, Fusion Eng. Des.<br />

M. BARUZZO, T. BOLZONELLA, G. CALABRO’, F. CRISANTI, A. CUCCHIARO, D. MARCUZZI, W. RIGATO, M. SCHNEIDER, P. SONATO, M.<br />

VALISA, P. ZACCARIA, J.F. ARTAUD, M. BASIUK, A. CARDINALI, F. IMBEAUX, L. LAURO TARONI, M. MARINUCCI, P. MANTICA, F. ZONCA:<br />

Requirements specification for the neutral beam injector on FAST, Fusion Eng. Des.<br />

G. VARANO, L. BONCAGNI, S. GALEANI, G. GRANUCCI, V. VITALE, L. ZACCARIAN: Experimental results on elongation control using<br />

dynamic input allocation at FTU, Fusion Eng. Des.<br />

L. BONCAGNI, Y. SADEGHI, C. CENTIOLI, S. SINIBALDI, V. VITALE, L. ZACCARIAN, G. ZAMBORLINI: Progress in the migration towards the<br />

real time framework MARTe at the FTU tokamak, Fusion Eng. Des.<br />

G. MAZZITELLI, M.L. APICELLA, A. ALEXEYEV AND FTU TEAM: Heat loads on FTU liquid lithium limiter, Fusion Eng. Des.<br />

M. RIVA, B. ESPOSITO, D. MAROCCO, F. BELLI, B. SYME AND JET–EFDA CONTRIBUTORS: The new <strong>di</strong>gital electronics for the JET neutron<br />

profile monitor: performances and first experimental results, Fusion Eng. Des.<br />

R. BONIFETTO, P.K. DOMALAPALLY, G.M. POLLI, L. SAVOLDI RICHARD, S. TURTU, R. VILLARI, R. ZANINO: Computation of JT–60SA TF coil<br />

temperature margin, Fusion Eng. Des.<br />

H. FERNANDES, F. GOMORY, A. DELLA CORTE, G. CELENTANO, J. SOUC, C. SILVA, I. CARVALHO, R. GOMES, A. DI ZENOBIO, G. MESSINA:<br />

Toroidal high temperature superconducting coils for ISTTOK, Fusion Eng. Des.<br />

M. ANGELONE, M. PILLON, G. PRESTOPINO, M. MARINELLI, E. MILANI, C. VERONA , G. VERONA-RINATI, G. AIELLI, R. CARDARELLI, R.<br />

SANTONICO, R.BEDOGNI, A. ESPOSITO: Thermal and fast neutron dosimety using artificial single crystal <strong>di</strong>amond detectors, Ra<strong>di</strong>at. Meas.<br />

M. ANGELONE, P. BATISTONI, F. MORO, M. PILLON, R.VILLARI, R. BEDOGNI, M. CHITI, A. GENTILE, A. ESPOSITO: Mixed n–γ fields<br />

dosimetry at low doses by means of <strong>di</strong>fferent solid state dosimetry, Ra<strong>di</strong>at. Meas.<br />

T. PINNA: Stu<strong>di</strong>es for the preparation of the preliminary safety reports for the european test blanket system, Fusion Eng. Des.<br />

S. ROCCELLA, G. BURRASCA, E. CACCIOTTI, A. CASTILLO, A. MANCINI, A. PIZZUTO, A. TATI’, E. VISCA: Non–destructive methods for the<br />

defect detection in the ITER high heat flux components, Fusion Eng. Des.<br />

R. BEDOGNI, A. ESPOSITO, A. GENTILE, M. ANGELONE, M. PILLON: Comparing active and passive bonner sphere spectrometers in the<br />

2.5 MeV quasi mono–energetic neutron field of the <strong>ENEA</strong>–Frascati neutron generator (FNG), Ra<strong>di</strong>at. Meas.


publications and events (cont’d.)<br />

progress report<br />

2010<br />

109<br />

M. PILLON, M. ANGELONE, S. SANDRI: Measurements of the activation and decay heat produced in materials irra<strong>di</strong>ated with D–T<br />

neutrons. Comparison with easy-2007 code pre<strong>di</strong>ctions, Fusion Sci. Technol.<br />

F. BORGONONI, S. TOSTI, C. RIZZIELLO, M. VADRUCCI, N. GHIRELLI, K. LIGER: Multi physic approach for membrane reactor modelling for<br />

wet gas detritiation, Fusion Sci. Technol.<br />

V. COCILOVO, R. DE ANGELIS, M.T. PORFIRI: A channel facility for Iter safety relevant dust mobilization stu<strong>di</strong>es, Fusion Sci. Technol.<br />

F. BORGOGNONI, S. TOSTI, M. VADRUCCI, A. SANTUCCI: Pure hydrogen production in a Pd–Ag multi–membranes reactor by methane<br />

reforming, Int. J. Hydrogen Energy<br />

A. VANNOZZI, G. CELENTANO: Development and characterization of nickel–copper–based substrates fo 2nd generation high–critical<br />

temperature superconductor tapes, In “Copper Alloys: Preparation, Properties and Application”<br />

P. COSTA, C. NERI, M. SPAGNOLO, F. MICCHETTI: A software platform for the optimization of IVVS viewing performances, Proc. of the<br />

2010 EnginSoft International Conference - CAE Technologies for Industry and ANSYS Italian Conference<br />

L. DI PACE, D. CARLONI, L. PERNA, S. PACI: Application of pactiter V3.3 code to the ACPS assessment of ITER neutral beam injectors<br />

primary heat transfer system, Fusion Sci. Technol.<br />

M. ANGELONE, P. BATISTONI, F. MORO, M. PILLON, R. VILLARI, M. LOUGHLIN: A Neutronics shiel<strong>di</strong>ng mock–up experiment for reduction<br />

of uncertainty on the pre<strong>di</strong>ction of the ITER–TFC nuclear heating, Fusion Sci. Technol.<br />

E. VISCA, A. PIZZUTO, B. RICCARDI, S. ROCCELLA, G.P. SANGUINETTI: A reliable technology to manufacture the ITER inner vertical target,<br />

Fusion Sci. Technol.<br />

A.A. TUCCILLO ON BEHALF OF FTU TEAM AND A. ALEXEYEV, L. AMICUCCI, A. BIANCALANI, A. BIERWAGE, G. BREYANNIS, I.<br />

CHAVDAROVSKI, L. CHEN, F. DE LUCA, Z.O. GUIMARAES-FILHO, A. JACCHIA, E. LAZZARO, F. PEGORARO, M. ROMANELLI, X. WANG:<br />

Overview of the FTU results, Nucl. Fusion<br />

V. PERICOLI–RIDOLFINI: The effect of the lower hybrid waves on turbulence and on transport of particles and energy in the FTU tokamak<br />

scrape–off layer plasma, Plasma Phys. Control. Fusion<br />

V. PERICOLI–RIDOLFINI, M.L. APICELLA, G. CALABRO’, C. CIANFARANI, E. GIOVANNOZZI, L. PANACCIONE: Lower hybrid current drive<br />

efficiency in tokamaks and wave scatteringby density fluctuations at the plasma edge, Nucl. Fusion<br />

P. BURATTI, M. BARUZZO, R.J. BUTTERY, C.D. CHALLIS, I.T. CHAPMAN, F. CRISANTI, L. FIGINI, M. GRYAZNEVICH, T.C. HENDER, D.F.<br />

HOWELL, H. HAN, E. JOFFRIN, J. HOBIRK, F. IMBEAUX, O.J. KWON, X. LITAUDON,J. MAILLOUX AND JET–EFDA CONTRIBUTORS: Kink<br />

instabilities in high–beta JET advanced scenarios, Nucl. Fusion<br />

Contributions to conferences<br />

O. TUDISCO, C. MAZZOTTA, A. BOTRUGNO, G. MAZZITELLI, M.L. APICELLA, G. APRUZZESE, D. FRIGIONE, L. GABELLIERI, A. ROMANO and<br />

FTU TEAM: Peaked density profiles and MHD activity on FTU in lithium dominated <strong>di</strong>scharges, 2nd International Symposium on Plasma<br />

Surface Interaction Toki, Gifu (Japan), January 18-20, 2010<br />

G. MAZZITELLI, M.L. APICELLA, G. APRUZZESE, R. DE ANGELIS, D. FRIGIONE, E. GIOVANNOZZI, L. GABELLIERI, G. GRANUCCI, C.<br />

MAZZOTTA, M. MARINUCCI, A. ROMANO, O. TUDISCO, FTU TEAM AND ECRH TEAM: Review of FTU results with the liquid lithium limiter,<br />

2nd International Symposium on Plasma Surface Interaction Toki, Gifu (Japan), January 18–20, 2010<br />

L. GABELLIERI, D. PACELLA, D. MAZON. A. ROMANO: A new SXR tomography with energy <strong>di</strong>scrimination capability, 6th Workshop on<br />

Fusion Data Processing, Validation and Analysis Madrid (Spain), January 25-27, 2010<br />

C. CASTALDO: Novel <strong>di</strong>agnostics for dust in space, laboratory and fusion plasmas, Plasma Diagnostics 2010 Pont à Mousson, Lorrain<br />

(France), April 12-16, 2010<br />

C. DI TROIA, S. BRIGUGLIO, G. CALABRÒ, A. CARDINALI, F. CRISANTI, G. FOGACCIA, M. MARINUCCI, G. VLAD, F. ZONCA: Fast ion transport<br />

and confinement in the FAST conceptual design, U.S. Transport Task Force Workshop Annapolis, MD (USA), April 13–16, 2010<br />

A.V. MILOVANOV, F. ZONCA: Aspects of complex behavior in magnetically confined plasma with intense energetic particlepopulation, 8th<br />

Workshop on Complex Systems of Charged Particles and their Interaction with Electromagnetic Ra<strong>di</strong>ation Moscow (Russia), April 14–16, 2010<br />

A. CARDINALI, F. SANTINI: Lower hybrid current drive at densities required for thermonuclear reactors, Int. Sherwood Fusion Theory<br />

Conference Seattle, Washington (USA), April 19–21, 2010<br />

F.P. ORSITTO, A. BIBOC, P. GAUDIO, M. GELFUSA, E. GIOVANNOZZI, C. MAZZOTTA, A. MURARI, AND JET EFDA CONTRIBUTORS: Mutual<br />

interaction of Faraday rotation and Cotton Mouton phase shift in JET polarimetric measurements, 18th High Temperature Plasma<br />

Diagnostics (HTPD-18) Wildwood, NJ (USA), May 16–20, 2010


110<br />

progress report<br />

2010<br />

A. ROMANO, D. PACELLA, D. MAZON, F. MURTAS, P. MALARD, L. GABELLIERI, B. TILIA, V. PIERGOTTI, G. CORRADI: Characterization of a 2D soft–X<br />

ray tomography camera with <strong>di</strong>scrimination in energy bands, 18th High–Temperature Plasma Diagnostics (HTPD-18) Wildwood, NJ, (USA), May<br />

16-20, 2010<br />

E. GIOVANNOZZI, M. BEURSKENS, M. KEMPENAARS, R. PASQUALOTTO, A. RYDZY AND JET EFDA CONTRIBUTORS: Detection of dust on JET with<br />

the high resolution Thomson scattering systems, 18th High–Temperature Plasma Diagnostics (HTPD–18) Wildwood, NJ, (USA), May 16–20, 2010<br />

L. BONCAGNI, Y. SADEGHI, D. CARNEVALE, G. MAZZITELLI, A. NETO, D. PUCCI, F. SARTORI, S. SINIBALDI, V. VITALE, R. VITELLI, L.<br />

ZACCARIAN, S. MONACO, G. ZAMBORLINI: First steps in the FTU migration towards a modular and <strong>di</strong>stributed real–time<br />

controlarchitecture based on MARTe, 17th Real Time Conference (RT10) Lisboa (Portugal), May 24–28, 2010<br />

L. BONCAGNI, A. BARBALACE, Y. SADEGHI, M. POMPEI, L. ZACCARIAN, F. SARTORI: Switched ethernet in synchronized <strong>di</strong>stributed control<br />

systems using RTnet, 17th Real Time Conference (RT10) Lisboa (Portugal), May 24–28, 2010<br />

A.V. MILOVANOV, F. ZONCA: Aspects of complex behavior in magnetically confined plasma with intense energetic particlepopulation,<br />

Birkeland Workshop on Complex Natural Systems Tromso (Norway), May 27–31, 2010<br />

E. VISCA, A. PIZZUTO, S. ROCCELLA: Tecnologie per la costruzione <strong>di</strong> componenti ad alto flusso termico per reattori a fusione, XXVIII<br />

Congresso UIT sulla Trasmissione del Calore Brescia (Italy), June 21–23, 2010<br />

V. PERICOLI RIDOLFINI, G. CALABRÒ, E. GIOVANNOZZI, L. PANACCIONE, A.A. TUCCILLO: LHCD efficiency and scattering by density<br />

fluctuations at the plasma edge, 37th EPS Conference on Plasma Physics Dublin (Ireland), June 21–25, 2010<br />

G. CALABRÒ, D.C. MCDONALD, M. BEURSKENS, C.F. MAGGI, I. DAY, E. DE LA LUNA, (INVITED PAPER) T. EICH, N. FEDORCZAK, O. FORD, E.<br />

GIOVANNOZZI, C. GIROUD, P. GOHIL, M. LENNHOLM, P.J. LOMAS, J. LONNROTH, G.P. MADDISON, I. NUNES, V. PERICOLI–RIDOLFINI, F. RYTER,<br />

G. SAIBENE, R. SARTORI, W. STUDHOLME, E. SURREY, I. VOITSEKHOVITCH, K.D. ZASTROW AND JET–EFDA CONTRIBUTORS: H–Mode<br />

threshold stu<strong>di</strong>es in helium–4 JET plasmas, 37th EPS Conference on Plasma Physics Dublin (Ireland), June 21–25, 2010<br />

V. PERICOLI–RIDOLFINI: Increased particle and energy transport induced by LH waves in the tokamak scrape–off layer plasma, 37th EPS<br />

Conference on Plasma Physics Dublin (Ireland), June 21–25, 2010<br />

M.L. APICELLA, G. APRUZZESE, G. MAZZITELLI, A.G. ALEKSEYEV, A. BOTRUGNO, P. BURATTI, R. DE ANGELIS, H. KROEGLER, V.B.<br />

LAZAREV, S.V. MIRNOV, R. ZAGORSKI: Ra<strong>di</strong>ative layer with a liquid ithium limiter on FTU, 37th EPS Conference on Plasma Physics Dublin<br />

(Ireland), June 21–25, 2010<br />

G. CALABRO’, E. GIOVANNOZZI, R. RAMOGIDA, F. CRISANTI, C. LABATE, M. MATTEI, P. MICOZZI, G. VLAD: Modelling of FAST equilibrium<br />

configurations by a toroidal multipolar expansion codeusing Kepler workflows, 37th EPS Conference on Plasma Physics Dublin (Ireland),<br />

June 21–25, 2010<br />

A. BIERWAGE, L. CHEN, F. ZONCA: Pressure–gra<strong>di</strong>ent–induced Alfvén eigenmodes destabilized by ion temperature gra<strong>di</strong>ent, 37th EPS<br />

Conference on Plasma Physics Dublin (Ireland), June 21–25, 2010<br />

A. JACCHIA, S. CIRANT, F. DE LUCA, P. BURATTI, E. LAZZARO, O. TUDISCO, C. MAZZOTTA, G. CALABRO’ G. RAMOGIDA, C. CIANFARANI,<br />

D. MAROCCO, G. GROSSETTI, G. GRANUCCI, O. D’ARCANGELO, W. BIN AND FTU AND ECRH TEAM: Density response to modulated EC<br />

heating in FTU tokamak, 37th EPS Conference on Plasma Physics Dublin (Ireland), June 21–25, 2010<br />

A. BOTRUGNO, P. BURATTI, F. ZONCA: Comparison between BAE observations at FTU and theoretical models, 37th EPS Conference on<br />

Plasma Physics Dublin (Ireland), June 21–25, 2010<br />

M. GONICHE, Y. BARANOV, P. BONOLI, G. CALABRO’, A. CARDINALI, C. CASTALDO, R. CESARIO, J. DECKER, J. GARCIA, G. GIRUZZI, E.<br />

JOFFRIN, A. HUBBARD, K. KIROV, X. LITAUDON, J. MAILLOUX, R. PARKER (Invited Paper): Lower hybrid current drive for the steady state<br />

scenario, 37th EPS Conference on Plasma Physics Dublin (Ireland), June 21–25, 2010<br />

B. BAIOCCHI, G. CALABRÒ, L. LAURO–TARONI, P. MANTICA, A. CARDINALI, G. CORRIGAN, F. CRISANTI, D. FARINA, L. FIGINI, G. GIRUZZI,<br />

T. JOHNSON, M. MARINUCCI, V. PARAIL: Pre<strong>di</strong>ctive modelling of H–mode and steady-state scenarios in FAST, 37th EPS Conference on<br />

Plasma Physics Dublin (Ireland), June 21–25, 2010<br />

M. BARUZZO, M. SCHNEIDER, V. BASIUK, A. CARDINALI, M. MARINUCCI, J.F. ARTAUD, O. ASUNTA, T. BOLZONELLA, F. CRISANTI, R.<br />

DUMONT, G. GIRUZZI, F. IMBEAUX, P. MANTICA, M. VALISA, F. ZONCA: First NBI configuration study for FAST proposal, 37th EPS<br />

Conference on Plasma Physics Dublin (Ireland), June 21-25, 2010<br />

A. BIANCALANI, L. CHEN, F. PEGORARO, F. ZONCA: Continuous spectrum of shear Alfvén waves inside magnetic islands, 37th EPS<br />

Conference on Plasma Physics Dublin (Ireland), June 21–25, 2010<br />

L. FRASSINETTI, M.N.A. BEURSKENS, D.C. MCDONALD, J. HOBIRK, D. WARZOSO, P. BURATTI, F. CRISANTI, C. CHALLIS, E. GIOVANNOZZI, E.<br />

JOFFRIN, P. LOMAS, J. LONNROTH, C. MAGGI, I. NUNES, S. SAARELMA, G. SAIBENE AND JET–EFDA CONTRIBUTORS: Pedestal confinement in<br />

hybrid versus baseline plasmas in JET, 37th EPS Conference on Plasma Physics Dublin (Ireland), June 21–25, 2010


publications and events (cont’d.)<br />

progress report<br />

2010<br />

111<br />

A.A. ANGRISANI, A. AUGIERI, L. CIONTEA, G. CONTINI, I. DAVOLI, V. GALLUZZI, A. MANCINI, A. RUFOLONI, T. PETRISOR, A. VANNOZZI, G.<br />

CELENTANO: Analysis of YBCO phase formation in thin films grown using a metal propionate coatingsolution, Applied Superconductivity<br />

Conference (ASC 2010) Washington D.C. (USA), August 1–6, 2010<br />

A. AUGIERI, V. GALLUZZI, A.A. ANGRISANI, A. MANCINI, A. RUFOLONI, A. VANNOZZI, G. CELENTANO, E. SILVA, N. POMPEO, T. PETRISOR,<br />

L. CIONTEA: Pinning properties of BaZrO 3-Y Ba 2 Cu 3 O 7-x thin films deposited by PLD and MOD, Applied Superconductivity Conference<br />

(ASC 2010) Washington D.C. (USA), August 1–6, 2010<br />

G. MESSINA, G. CELENTANO, G. GIORGI, F. MAIERNA, S. RUECA, R. VIOLA, A. DELLA CORTE: Design and manufacturing of HTS coils for axial<br />

flux electrical machine prototype, Applied Superconductivity Conference (ASC 2010) Washington D.C. (USA), August 1–6, 2010<br />

S. GAUDIO, G. DE MARZI, G. CELENTANO, A. AUGIERI, V. GALLUZZI, A. MANCINI, A. RUFOLONI, A. VANNOZZI, A. DELLA CORTE, U.<br />

GAMBARDELLA, A. SAGGESE, J.J. JIANG, J. WEISS, E. HELLSTROM, D. LARBALESTIER: The effect of doping on the magnetic properties in<br />

Ba(Fe 1-x Co x ) 2 As 2 polycristalline samples, Applied Superconductivity Conference (ASC 2010) Washington D.C. (USA), August 1–6, 2010<br />

V. CORATO, L. MUZZI, U. BESI VETRELLA, C. FIAMOZZI ZIGNANI, A. DELLA CORTE: Mapping of the transversal resistivity matrix measured on<br />

NbTi and Nb 3 Sn superconductingstrands, Applied Superconductivity Conference (ASC 2010) Washington D.C. (USA), August 1–6, 2010<br />

G. DE MARZI, L. MUZZI, V. CORATO, C. FIAMOZZI ZIGNANI, A. DELLA CORTE, G. MONDONICO, B. SEEBER, C. SENATORE, R. FLUKIGER:<br />

Improvement of electromechanical properties of stainless steel jacketed Nb 3 Sn wires, Applied Superconductivity Conference (ASC 2010)<br />

Washington D.C. (USA), August 1–6, 2010<br />

A. DI ZENOBIO, A. DELLA CORTE, L. MUZZI, G.M. POLLI, L. RECCIA,S. TURTU’, F. CRISANTI, A. CUCCHIARO, A. PIZZUTO, R. VILLARI: FAST:<br />

feasibility analysis for a completely superconducting magnet system, Applied Superconductivity Conference (ASC 2010) Washington D.C.<br />

(USA), August 1–6, 2010<br />

C. FIAMOZZI ZIGNANI, L. MUZZI, S. TURTU’, A. DELLA CORTE: The effect of strand ben<strong>di</strong>ng on the voltage–current characteristics of<br />

Nb 3 Sn cable–in–conduit conductors, Applied Superconductivity Conference (ASC 2010) Washington D.C. (USA), August 1–6, 2010<br />

A. MANCINI, G. CELENTANO, A. VANNOZZI, V. GALLUZZI, A. RUFOLONI, A. AUGIERI, S. GAUDIO, A.A. ANGRISANI, I. COLANTONI, I. DAVOLI:<br />

The oxidation behaviour at the Ni–W and CeO 2 interface with and without Pd over layer, Applied Superconductivity Conference (ASC<br />

2010) Washington D.C. (USA) August 1–6, 2010<br />

L. MUZZI, G. DE MARZI, U. BESI VETRELLA, C. FIAMOZZI ZIGNANI, V. CORATO, A. RUFOLONI, A. DELLA CORTE: Test results of a NbTi wire<br />

for the ITER PF 2–5 magnets: a validation of the 2–pinning components model, Applied Superconductivity Conference (ASC 2010)<br />

Washington D.C. (USA), August 1–6, 2010<br />

G.M. POLLI, L. AFFINITO, A. DELLA CORTE: Heat exchanger design for the 30 kA gas cooled current leads in the <strong>ENEA</strong> 12 T CICC facility,<br />

Applied Superconductivity Conference (ASC 2010) Washington D.C. (USA), August 1–6, 2010<br />

L. RECCIA, S. TURTU’, G.M. POLLI, L. AFFINITO, F. MAIERNA, A. DELLA CORTE, P. DECOOL, A. TORRE, H. CLOEZ, A. VOSTNER, A. DEVRED,<br />

D. BASSETTE, T. BOUTBOUL: Preparation of PF1/6 and PF2 conductor performance qualification sample, Applied Superconductivity<br />

Conference (ASC 2010) Washington D.C. (USA), August 1–6, 2010<br />

S. TURTU’, L. MUZZI, C. FIAMOZZI ZIGNANI, V. CORATO, A. DELLA CORTE, A. DI ZENOBIO, L. RECCIA: Role of the cross-section geometry in<br />

rectangular Nb 3 Sn CICC performance, Applied Superconductivity Conference (ASC 2010) Washington D.C. (USA), August 1–6, 2010<br />

A. VANNOZZI, V. GALLUZZI, A. MANCINI, A. RUFOLONI, A. AUGIERI, A.A. ANGRISANI, L. CIONTEA, Y. THALMAIER, T. PETRISOR, G.<br />

CELENTANO: Study of MgO–based buffer layer architecture for the development of Ni–Cu–based RABiTS YBCO coated conductor,<br />

APPLIED SUPERCONDUCTIVITY CONFERENCE (ASC 2010) WASHINGTON D.C. (USA), AUGUST 1–6, 2010<br />

A. CARDINALI, V. FUSCO: Analytical and numerical stu<strong>di</strong>es of the cold electromagnetic LH wave equation in the modeconverzion regime, Joint<br />

Varenna–Lausanne International Workshop on Theory of Fusion Plasmas Villa Monastero, Varenna (Italy), August 30 – September 3, 2010<br />

F. ZONCA, A. BIANCALANI, I. CHAVDAROVSKI, L. CHEN, C. DI TROIA, X. WNG: Kinetic structures of shear Alfvén and acoustic wave spectra<br />

in burning plasmas, Joint Varenna–Lausanne International Workshop on Theory of Fusion Plasmas Villa Monastero, Varenna (Italy)<br />

August 30 – September 3, 2010<br />

R. CESARIO, L. AMICUCCI, C. CASTALDO, D. DE ARCANGELIS, M. FERRARI, M. MARINUCCI, F. NAPOLI, E. POLLURA, L. PANACCIONE, A.A.<br />

TUCCILLO, AND FTU TEAM: Parametric instability and lower hybrid current drive at plasma densities required forthermonuclear reactors, Joint<br />

Varenna–Lausanne International Workshop on Theory of Fusion Plasmas Villa Monastero, Varenna (Italy) August 30 – September 3, 2010<br />

M. ANGELONE, M. PILLON, G. PRESTOPINO, M. MARINELLI, E. MILANI, C. VERONA , G. VERONA–RINATI, G. AIELLI, R. CARDARELLI, R.<br />

SANTONICO, R.BEDOGNI, A. ESPOSITO: Thermal and fast neutron dosimety using artificial single crystal <strong>di</strong>amond detectors, 16th International<br />

Conference on Solid State Dosimetry (SSD–16) Sydney (Australia), September 19–24, 2010<br />

F. MIRIZZI, J.F. ARTAUD, Y.S. BAE, J. BELO, G. BERGER–BY, J.M. BERNARD, PH. CARA, A. CARDINALI, C. CASTALDO, S. CECCUZZI, R. CESARIO,


112<br />

progress report<br />

2010<br />

J. DECKER, L. DELPECH, A. EKEDAHL, J. GARCIA, P. GARIBALDI, M. GONICHE, D. GUILHEM, J. HILLAIRET, G.T. HOANG, Q.Y. HUANG, F. IMBEAUX,<br />

H. JIA, S.H. KIM, Y. LAUSENAZ, R. MAGGIORA, R. MAGNE, L. MARFISI, S. MESCHINO, D. MILANESIO, W. NAMKUNG, L. PAJEWSKI, L. PANACCIONE,<br />

Y. PEYSSON, A. SAILLE, G. SCHETTINI, M. SCHNEIDER, P.K. SHARMA, A.A. TUCCILLO, O. TUDISCO, G. VECCHI, R. VILLARI, K. VULLIEZ, Y. WU, Q.<br />

ZENG: The revised LHCD system for ITER, Workshop on RF Heating Technology of Fusion Plasmas Como (Italy), September 13–15, 2010<br />

S. CECCUZZI, F. MIRIZZI, S. MESCHINO, L. PAJEWSKI, G. SCHETTINI, J.F. ARTAUD, Y.S. BAE, J. BELO, G. BERGER–BY, J.M. BERNARD, PH.<br />

CARA, A. CARDINALI, C. CASTALDO, R. CESARIO, J. DECKER, L. DELPECH, A. EKEDAHL, J. GARCIA, P. GARIBALDI, M. GONICHE, D.<br />

GUILHEM, J. HILLAIRET, G.T. HOANG, Q.Y. HUANG, F. IMBEAUX, H. JIA, S.H. KIM, Y. LAUSENAZ, R. MAGGIORA, R. MAGNE, L. MARFISI, D.<br />

MILANESIO, W. NAMKUNG, L. PANACCIONE, Y. PEYSSON, A. SAILLE, M. SCHNEIDER, P.K. SHARMA, A.A. TUCCILLO, O. TUDISCO, G. VECCHI,<br />

R. VILLARI, K. VULLIEZ, Y. WU, Q. ZENG: Bends and mode filters in oversized rectangular waveguide for the ITER relevant LHCD system,<br />

Workshop on RF Heating Technology of Fusion Plasmas Como (Italy) September 13–15, 2010<br />

S. ALMAVIVA, L. CANEVE, F. COLAO, R. FANTONI, G. MADDALUNO: LIBS characterization of ITER–like tiles superficial layers, 6th International<br />

Conference on Laser–induced Breakdown Spectroscopy (LIBS 2010) Memphis, TN (USA), September 13–17, 2010<br />

M. ANGELONE, P. BATISTONI, F. MORO, M. PILLON, R.VILLARI, R. BEDOGNI, M. CHITI, A. GENTILE. A. ESPOSITO: Mixed n–γ fields<br />

dosimetry at low doses by means of <strong>di</strong>fferent solid state dosimetry, 16th International Conference on Solid State Dosimetry (SSD–16)<br />

Sydney (Australia), September 19–24, 2010<br />

R. BEDOGNI, A. ESPOSITO, A. GENTILE, M. ANGELONE, M. PILLON: Comparing active and passive bonner sphere spectrometers in the<br />

2.5 MeV quasimono–energetic neutron field of the <strong>ENEA</strong>–Frascati neutron generator (FNG), 16th International Conference on Solid State<br />

Dosimetry (SSD–16) Sydney (Australia), September 19–24, 2010<br />

P. BURATTI, F. ALLADIO: Magnetic reconnection, current filaments and ejection events in laboratory plasmas, XCVI Congresso Nazionale<br />

Società Italiana <strong>di</strong> Fisica (SIF) Bologna (Italia), September 20–24, 2010<br />

A. CARDINALI: Teoria Hamiltoniana nello stu<strong>di</strong>o della propagazione dell’onda ibrida inferiore in plasmiconfinati magneticamente, XCVI<br />

Congresso Nazionale Società Italiana <strong>di</strong> Fisica (SIF) Bologna (Italia), September 20–24, 2010<br />

R. CESARIO: Generazione <strong>di</strong> corrente a densità <strong>di</strong> plasma richieste per reattori a fusione termonucleare (Invited Paper), XCVI Congresso<br />

Nazionale Società Italiana <strong>di</strong> Fisica (SIF) Bologna (Italia), September 20–24, 2010<br />

C. NERI, P. COSTA, M. FERRI DE COLLIBUS, M. FLOREAN, G. MUGNAINI, M. PILLON, F. POLLASTRONE, P. ROSSI: ITER in vessel viewing system<br />

design and assessment activities, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

E. VISCA, E. CACCIOTTI, A. KOMAROV, S. LIBERA, N. LITUNOVSKY, A. MAKHANKOV, A. MANCINI, M. MEROLA, A. PIZZUTO, B. RICCARDI,<br />

S. ROCCELLA: Manufacturing, testing and post–test examination of ITER <strong>di</strong>vertor vertical target W smallscale mock–ups, 26th<br />

Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 - October 1, 2010<br />

F. MIRIZZI, S. CECCUZZI, S. MESCHINO, J.F. ARTAUD, J.H. BELO, G. BERGER-BY, J.M. BERNARD, A. CARDINALI, C. CASTALDO, R.<br />

CESARIO, J. DECKER, L. DELPECH, A. EKEDAHL, J. GARCIA, P. GARIBALDI, M. GONICHE, D. GUILHEM, G.T. HOANG, J. HUA, Q.Y. HUANG,<br />

J. HILLAIRET, F. IMBEAUX, F. KAZARIAN, S.H. KIM, X. LITAUDON, R. MAGGIORA, R. MAGNE, L. MARFISI, D. MILANESIO, W. NAMKUNG, L.<br />

PAJEWSKI, L. PANACCIONE, Y. PEYSSON, P.K. SHARMA, G. SCHETTINI, M. SCHNEIDER, A.A. TUCCILLO, O. TUDISCO, G. VECCHI, R.<br />

VILLARI, K. VULLIEZ: Contribution to the design of the main transmission line for the ITER relevant LHCD system, 26th Symposium on<br />

Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

A. COLETTI, O. BAULAIGUE, P. CARA, R. COLETTI, A. FERRO, E. GAIO, M. MATSUKAWA, L. NOVELLO, M. SANTINELLI, K. SHIMADA, F. STARACE,<br />

T. TERAKADO, K. YAMAUCHI: JT–60SA power supply system, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27<br />

– October 1, 2010<br />

P. ROSSI, M. CAPOBIANCHI, F. CRESCENZI, A. MASSIMI, G. MUGNAINI, C. NARDI, A. PIZZUTO, L. BETTINALI, J. KNASTER, H. RAJAINMAKI,<br />

D. EVANS: Ultimate tensile strength testing campaign on ITER pre–compression ring mock–ups, 26th Symposium on Fusion Technology<br />

(SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

F. CRESCENZI, F. MARINI, C. NARDI, A. PIZZUTO, P. ROSSI, L. VERDINI, H. RAJAINMAKI, J. KNASTER, L. BETTINALI: Mechanical<br />

characterization of glass fibre–epoxy composite material for ITER pre–compression rings, 26th Symposium on Fusion Technology (SOFT)<br />

Porto (Portugal), September 27 – October 1, 2010<br />

S. CECCUZZI, S. MESCHINO, F. MIRIZZI, J.F. ARTAUD, Y.S. BAE, J. BELO, G. BERGER-BY, J.M. BERNARD, PH. CARA, A. CARDINALI, C.<br />

CASTALDO, R. CESARIO J. DECKER, L. DELPECH, A. EKEDAHL, J. GARCIA, P. GARIBALDI, M. GONICHE, D. GUILHEM, J. HILLAIRET, G.T. HOANG,<br />

Q.Y. HUANG, F. IMBEAUX, H. JIA, S.H. KIM, Y. LAUSENAZ, R. MAGGIORA, R. MAGNE, L. MARFISI, D. MILANESIO, W. NAMKUNG, L. PAJEWSKI,<br />

L. PANACCIONE, Y. PEYSSON, A. SAILLE, G. SCHETTINI, M. SCHNEIDER, P.K. SHARMA, A.A. TUCCILLO, O. TUDISCO, G. VECCHI, R. VILLARI, K.<br />

VULLIEZ, Y. WU, Q. ZENG: Mode filters for oversized transmission lines, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal),<br />

September 27 – October 1, 2010<br />

R. VILLARI, L. PETRIZZI, G. BROLATTI, E. DALY, M. LOUGHLIN, A. MARTIN, F. MORO, E. POLUNOVSKY: Three–<strong>di</strong>mensional neutronic


publications and events (cont’d.)<br />

progress report<br />

2010<br />

113<br />

analysis of the ITER in–vessel coils, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

S. TOSTI, C. RIZZELLO, F. BORGOGNONI, N. GHIRELLI, A. SANTUCCI: Design of Pd–based membrane reactor for gas detritiation, 26th<br />

Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

F. MORO, B. ESPOSITO, D. MAROCCO, R. VILLARI, L. PETRIZZI, E. ANDERSSON SUNDEN, S. CONROY, G. ERICSSON, M. GATU JOHNSON, M.<br />

DAPENA: Neutronic calculations in support of the design of the ITER high resolution neutron spectrometer, 26th Symposium on Fusion<br />

Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

U. FISCHER, D. GROBE, F. MORO, P. PERESLAVTSEV, R. VILLARI, L. PETRIZZI, V. WEBER: Integral approach for neutronics analyses of the<br />

European test blanket modules in ITER, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

M. DAPENA, L. PETRIZZI, F. MORO: Preliminary neutronic analyses of ITER high resolution neutron spectrometer collimator, 26th<br />

Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

G. CALABRO’, V. COCILOVO, F. CRISANTI, A. CUCCHIARO, R. MAZZUCA, A. PIZZUTO, G. RAMOGIDA, C. RITA, Y. SADEGHI: Active toroidal field ripple<br />

reduction system in FAST, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

A. CUCCHIARO, G. BROLATTI, G. CALABRO’, V. COCILOVO, P. FROSI, F. CRESCENZI, F. CRISANTI, G. MADDALUNO, V. PERICOLI-RIDOLFINI,<br />

A. PIZZUTO, C. RITA, G. RAMOGIDA, S. ROCCELLA, P. ROSSI: Engineering evolution of the FAST machine, 26th Symposium on Fusion<br />

Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

F. CRISANTI, A. CUCCHIARO, R. ALBANESE, G. ARTASERSE, M. BARUZZO, T. BOLZONELLA, G. BROLATTI, G. CALABRO’, F. CRESCENZI,<br />

R. COLETTI, P. COSTA, A. DELLA CORTE, A. DI ZENOBIO, P. FROSI, L. LAURO TARONI, G. MADDALUNO, D. MARCUZZI, F. MAVIGLIA, L.<br />

MUZZI, V. PERICOLI-RIDOLFINI, A. PIZZUTO, G. POLLI, G. RAMOGIDA, L. RECCIA, V. RIGATO, C. RITA, S. ROCCELLA, M. SANTINELLI, P.<br />

SONATO, S. TURTU’, M. VALISA, B. VIOLA: FAST: a European ITER satellite experiment in the view of DEMO (Invited Paper), 26th<br />

Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

G. POLLI, A. DELLA CORTE, A. DI ZENOBIO, L. MUZZI, L. RECCIA, S. TURTU’, G. BROLATTI, F. CRISANTI, A. CUCCHIARO, A. PIZZUTO, R.<br />

VILLARI: A thermo–hydraulic analysis of the superconducting proposal for the TF magnet system of FAST, 26th Symposium on Fusion<br />

Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

V. PERICOLI-RIDOLFINI, R. ZAGORSKI, B. VIOLA, G. CALABRO’, G. CORRIGAN, F. CRISANTI, G. MADDALUNO, L. LAURO TARONI: Simulations of the SOL<br />

plasma for FAST, a proposed ITER satellite tokamak, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

F. MAVIGLIA, G, ARTASERSE, R. ALBANESE, G. CALABRO’, F. CRISANTI, A. PIRONTI, A. PIZZUTO, G. RAMOGIDA: Poloidal field circuits sensitivity<br />

stu<strong>di</strong>es and shape control in FAST, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal) September 27 – October 1, 2010<br />

M. BARUZZO, T. BOLZONELLA, G. CALABRO’, F. CRISANTI, A. CUCCHIARO, D. MARCUZZI, W. RIGATO, M. SCHNEIDER, P. SONATO, M.<br />

VALISA, P. ZACCARIA, J.F. ARTAUD, M. BASIUK, A. CARDINALI, F. IMBEAUX, L. LAURO TARONI, M. MARINUCCI, P. MANTICA, F. ZONCA:<br />

Requirements specification for the neutral beam injector on FAST, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal),<br />

September 27 – October 1, 2010<br />

G. VARANO, L. BONCAGNI, S. GALEANI, G. GRANUCCI, V. VITALE, L. ZACCARIAN: Experimental results on elongation control using<br />

dynamic input allocation at FTU, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

L. BONCAGNI, Y. SADEGHI, C. CENTIOLI, S. SINIBALDI, V. VITALE, L. ZACCARIAN, G. ZAMBORLINI: Progress in the migration towards the real time<br />

framework MARTe at the FTU tokamak, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

G. MAZZITELLI, M.L. APICELLA, A. ALEXEYEV AND FTU TEAM: Heat loads on FTU liquid lithium limiter, 26th Symposium on Fusion<br />

Technology (SOFT) Porto (Portugal),ß September 27 – October 1, 2010<br />

M. RIVA, B. ESPOSITO, D. MAROCCO, F. BELLI, B. SYME AND JET–EFDA CONTRIBUTORS: The new <strong>di</strong>gital electronics for the JET neutron<br />

profile monitor: performances and firstexperimental results, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September<br />

27 – October 1, 2010<br />

R. BONIFETTO, P.K. DOMALAPALLY, G.M. POLLI, L. SAVOLDI RICHARD, S. TURTU, R. VILLARI, R. ZANINO: Computation of JT–60SA TF coil<br />

temperature margin, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

H. FERNANDES, F. GOMORY, A. DELLA CORTE, G. CELENTANO, J. SOUC, C. SILVA, I. CARVALHO, R. GOMES, A. DI ZENOBIO, G. MESSINA:<br />

Toroidal high temperature superconducting coils for ISTTOK, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal),<br />

September 27 – October 1, 2010<br />

P. BATISTONI, M. ANGELONE, P. CARCONI, U. FISCHER, D. LEICHTLE, A. KLIX, I. CODELI, M. PILLON, W. POHORECKI, A. TRKOV, R. VILLARI:<br />

Neutronics experiment on a HCLL breeder blanket mock–up, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal),<br />

September 27 – October 1, 2010<br />

M. ANGELONE: Neutronics shiel<strong>di</strong>ng experiment on a ITER mock–up to reduce the uncertainties on thepre<strong>di</strong>ctions of the toroidal field


114<br />

progress report<br />

2010<br />

coils nuclear heating, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

T. PINNA: Stu<strong>di</strong>es for the preparation of the preliminary safety reports for the european test blanket system, 26th Symposium on Fusion<br />

Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

S. ROCCELLA, G. BURRASCA, E. CACCIOTTI, A. CASTILLO, A. MANCINI, A. PIZZUTO, A. TATI’, E. VISCA: Non–destructive methods for the defect<br />

detection in the ITER high heat flux components, 26th Symposium on Fusion Technology (SOFT) Porto (Portugal), September 27 – October 1, 2010<br />

G.L. RAVERA, R. MAGGIORA, F. MIRIZZI, A.A. TUCCILLO: Performance of <strong>di</strong>fferent load tolerant external matching unit for the FAST–ICRH<br />

system, 40th European Microwave Conference (EUMW2010) Paris (France), September 28–30, 2010<br />

C. VERONA, M. MARINELLI, E. MILANI, G. PRESTOPINO, G. VERONA–RINATI, M. ANGELONE, M. PILLON: Effect of secondary electrons<br />

emission on the spectral responsivity of single crystal <strong>di</strong>amondbased Extreme–UV detector, 21st European Conference on Diamond,<br />

Diamond–like materials, Carbon Nanotubes, and Nitrides (DIAMOND 2010) Budapest (Hungary), September 5–9, 2010<br />

S. CECCUZZI, S. MESCHINO, F. MIRIZZI, G. SCHETTINI: Mode filters for oversized corrugated rectangular vaweguide, XVIII Riunione Nazionale<br />

<strong>di</strong> Elettromagnetismo (RiNEm 2010) e 1^ Conferenza Nazionale della Commissione URSI B, Benevento (Italy), September 6–10, 2010<br />

O. TUDISCO: Electron temperature characteristic length and profile resiliency in FTU, 3rd EFDA Transport Topical Group Meeting and<br />

15th EU–US Transport Task Force Workshop Cordoba (Spain), September 7–10, 2010<br />

C. MAZZOTTA, M. ROMANELLI, M.L. APICELLA, M. MARINUCCI, G. MAZZITELLI, O. TUDISCO AND FTU TEAM: Liquid lithium limiter<br />

<strong>di</strong>scharges at FTU: density profiles and microstability analysis, 3rd EFDA Transport Topical Group Meeting and 15th EU–US Transport<br />

Task Force Workshop Cordoba (Spain), September 7–10, 2010<br />

A. CARDINALI, G. CALABRO’, F. CRISANTI, C. DI TROIA, L. LAURO–TARONI, M. MARINUCCI, B. BAIOCCHI, M. BARUZZO, A. BIERWAGE, G.<br />

BREYIANNIS, S. BRIGUGLIO, G. FOGACCIA, P. MANTICA, G. VLAD, X. WANG, F. ZONCA, V. BASIUK, R. BILATO, M. BRAMBILLA, G. CORRIGAN, F.<br />

IMBREAUX, T. JOHNSON, V. PARAIL, S. PODDA, M. SCHNEIDER: H–mode scenarios in FAST with combined NNBI and ICRH, 3rd EFDA Transport<br />

Topical Group Meeting and 15th EU–US Transport Task Force Workshop Cordoba (Spain), September 7–10, 2010<br />

V. COCILOVO, R. DE ANGELIS, M.T. PORFIRI: A channel facility for Iter safety relevant dust mobilization stu<strong>di</strong>es, 19th Topical Meeting on<br />

Technology of Fusion Energy (TOFE) Las Vegas (USA), November 7–11, 2010<br />

F. CRISANTI, R. ALBANESE, F. ARTAUD, B. BAIOCCHI, M. BARUZZO, V. BASIUK, A. BIERWAGE, R. BILATO, T. BOLZONELLA, M. BRAMBILLA,<br />

S. BRIGUGLIO, G. CALABRO’, A. CARDINALI, G. CORRIGAN, A. CUCCHIARO, C. DI TROIA, D. FARINA, L. FIGINI, G. FOGACCIA, G. GIRUZZI,<br />

G. GRANUCCI, F. IMBEAUX, T. JOHNSON, L. LAURO TARONI, R. MAGGIORA, P. MANTICA, D. MILANESIO, V. PARAIL, V. PERICOLI-RIDOLFINI,<br />

A. PIZZUTO, S. PODDA, G. RAMOGIDA, M. SANTINELLI, M. SCHNEIDER, A. TUCCILLO, M. VALISA, R. VILLARI, B. VIOLA, G. VLAD, X. WANG,<br />

F. ZONCA: Scenario development for FAST in the view of ITER and DEMO, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea),<br />

October 11–16, 2010<br />

A. CARDINALI, M. BARUZZO, C. DI TROIA, M. MARINUCCI, A. BIERWAGE, G. BREYIANNIS, S. BRIGUGLIO, G. FOGACCIA, G. VLAD, X. WANG,<br />

F. ZONCA, V. BASIUK, R. BILATO, M. BRAMBILLA, F. IMBEAUX, S. PODDA, M. SCHNEIDER: Energetic particle physics in FAST H–mode scenario<br />

with combined NNBI and ICRH, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

P. MANTICA, B. BAIOCCHI, G. CALABRO’, L. LAURO TARONI,, O. ASUNTA, M. BARUZZO, A. CARDINALI, G. CORRIGAN, F. CRISANTI, D.<br />

FARINA, L. FIGINI, G. GIRUZZI, F. IMBEAUX, T. JOHNSON, M. MARINUCCI, V. PARAIL, A. SALMI, M. SCHNEIDER, M. VALISA: Physics based<br />

modelling of H–mode and advanced tokamak scenarios for FAST: analysis ofthe role of rotation in pre<strong>di</strong>cting core transport in future<br />

machines, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

M. TARDOCCHI, A. BRUSCHI, D. MAROCCO, N. NOCENTE, G. CALABRO’, A. CARDINALI, F. CRISANTI, B. ESPOSITO, L. FIGINI, G. GORINI,<br />

G. GROSSETTI, G. GROSSO, M. LONTANO, S. NOVAK, F. ORSITTO, U. TARTARI, O TUDISCO: Production and <strong>di</strong>agnosis of energetic particle<br />

in FAST, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

G. MAZZITELLI, M.L. APICELLA, D. FRIGIONE, G. MADDALUNO, M. MARINUCCI, C. MAZZOTTA, V. PERICOLI–RIDOLFINI, M. ROMANELLI, G.<br />

SZEPESI, O. TUDISCO AND FTU TEAM: FTU results with the liquid lithium limiter, 23rd IAEA Fusion Energy Conference (FEC) Daejon<br />

(Korea), October 11–16, 2010<br />

B. ESPOSITO, G. GRANUCCI, M. MARASCHEK, S. NOWAK, A. GUDE, V. IGOCHINE, R. MCDERMOTT, F. POLI, J. STOBER, W. SUTTROP, W.<br />

TREUTTERER, H. ZOHM AND ASDEX UPGRADE TEAM: Avoidance of <strong>di</strong>scruption at high‚ β n in ASDEX Upgrade with off-axis ECRH, 23rd<br />

IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

R. DE ANGELIS, F. ORSITTO, M. BARUZZO, P. BURATTI, B. ALPER, L. BARRERA, A. BOTRUGNO, M. BRIX, K. CROMBE’, L. FIGINI, A.<br />

FONSECA, C. GIROUD, N. HAWKES, D. HOWELL, E. DE LA LUNA, V. PERICOLI-RIDOLFINI, E. RACHLEW, O. TUDISCO AND JET–EFDA<br />

CONTRIBUTORS: Determination of q profiles in JET by consistency of motional stark effect and MHD modelocalization, 23rd IAEA Fusion<br />

Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

R. DE ANGELIS, F. ORSITTO, M. BARUZZO, P. BURATTI, B. ALPER, L. BARRERA, A. BOTRUGNO, M. BRIX, K. CROMBE’, L. FIGINI, A.


publications and events (cont’d.)<br />

progress report<br />

2010<br />

115<br />

FONSECA, C. GIROUD, N. HAWKES, D. HOWELL, E. DE LA LUNA, V. PERICOLI–RIDOLFINI, E. RACHLEW, O. TUDISCO AND JET–EFDA<br />

CONTRIBUTORS: Particle deposition, transport and fuelling in pellet injection experiments at JET, 23rd IAEA Fusion Energy Conference<br />

(FEC) Daejon (Korea), October 11–16, 2010<br />

P. BURATTI, M. BARUZZO, R.J. BUTTERY, C.D. CHALLIS, I.T. CHAPMAN, F. CRISANTI, L. FIGINI, M. GRYAZNEVICH, T.C. HENDER, D.F.<br />

HOWELL, H. HAN, E. JOFFRIN, J. HOBIRK, F. IMBEAUX, O.J. KWON, X. LITAUDON,J. MAILLOUX AND JET-EFDA CONTRIBUTORS: Kink<br />

instabilities in high–beta JET advanced scenarios, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

R. CESARIO, L. AMICUCCI, M.L. APICELLA, G. CALABRO’, A. CARDINALI, C. CASTALDO, C. CIANFARANI, D. FRIGIONE, M. MAZZITELLI, C.<br />

MAZZOTTA, L. PANACCIONE, V. PERICOLI-RIDOLFINI, A.A. TUCCILLO, O. TUDISCO AND FTU TEAM: Lower hybrid current drive at densities<br />

required for thermonuclear reactors, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

A.A. TUCCILLO ON BEHALF OF FTU TEAM AND A. ALEXEYEV, L. AMICUCCI, A. BIANCALANI, A. BIERWAGE, G. BREYANNIS, I.<br />

CHAVDAROVSKI, L. CHEN, F. DE LUCA, Z.O. GUIMARAES-FILHO, A. JACCHIA, E. LAZZARO, F. PEGORRO, M. ROMANELLI, X. WANG:<br />

Overview of the FTU results, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

G. GRANUCCI, G. RAMPONI, G. CALABRO’, F. CRISANTI, G. RAMOGIDA, W. BIN, A. BOTRUGNO, P. BURATTI, O. D’ARCANGELO, D.<br />

FRIGIONE, G. PUCELLA, A. ROMANO, O. TUDISCO, AND FTU TEAM: Plasma start–up results with EC assisted breakdown on FTU, 23rd<br />

IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

D.C. MCDONALD, G. CALABRO’, M. BEURSKENS, I. DAY, E, DE LA LUNA, T. EICH, N. FEDORCZAC, O. FORD, W. FUNDAMENSKI, C. GIROUD,<br />

P. GOHIL, M. LENNHOLM, J. LONNROTH, P.J. LOMAS, G.P. MADDISON, C.F. MAGGI, I. NUNES, G. SAIBENE, R. SARTORI, W. STUDHOLME,<br />

E. SURREY, I. VOITSEKOVITCH, K.D. ZATROW AND JET–EFDA CONTRIBUTORS: JET helium–4 ELMy H–mode stu<strong>di</strong>es, 23rd IAEA Fusion<br />

Energy Conference (FEC) Daejon (Korea) October 11–16, 2010<br />

E. JOFFRIN, C.D. CHALLIS, J. CITRIN, J. GARCIA, J. HOBIRK, I. JENKINS, J. LONNROTH, D.C. MCDONALD, P. MAGET, P. MANTICA, M.<br />

BEURSKENS, M. BRIX, P. BURATTI, F. CRISANTI, L. FRASSINETTI, C. GIROUD, F. IMBEAUX, M. PIOVESAN, F. RIMINI, G. SERGIENKO, A.C.C.<br />

SIPS, T. TALA, I. VOITSEKOVITCH AND JET–EFDA CONTRIBUTORS: High confinement hybrid scenario in JET and its significance for ITER,<br />

23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea) October 11–16, 2010<br />

J. MAILLOUX, X. LITAUDON, P.C. DE VRIES, J. GARCIA, I. JENKINS, B. ALPER, YU.BARANOV, M. BARUZZO, M. BEURSKENS, M. BRIX, P.<br />

BURATTI, G. CALABRÒ, R. CESARIO, C.D. CHALLIS, K. CROMBE, O. FORD, D. FRIGIONE, C. GIROUD, M. GONICHE, N. HAWKES, D.<br />

HOWELL, P. JACQUET, E. JOFFRIN, V. KIPTILY, K.K. KIROV, P. MAGET, D.C. MCDONALD, V. PERICOLI-RIDOLFINI, V. PLYUSIN, F. RIMINI, M.<br />

SCHNEIDER, S. SHARAPOV, C. SOZZI, I. VOITSEKOVITCH, L. ZABEO AND JET–EFDA CONTRIBUTORS: Towards a steasy–state scenario<br />

with ITER <strong>di</strong>mensionless parameters in JET, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

P. MAGET, H. LUTJENS, B. ALPER, M. BARUZZO, M. BRIX, P. BURATTI, R.J. BUTTERY, C. CHALLIS, R. COELHO, E. DE LA LUNA, C. GIROUD,<br />

N. HAWKES, G.T.A. HUYSMANS, I. JENKINS, X. LITAUDON, J. MAILLOUX, N. MELLET, D. MESHCHERIAKOV, M. OTTAVIANI, AND JET–EFDA<br />

CONTRIBUTORS: Non linear MHD modelling of NTMs in JET advanced scenarios, 23rd IAEA Fusion Energy Conference (FEC) Daejon<br />

(Korea), October 11–16, 2010<br />

P. MANTICA, C. ANGIONI, B. BAIOCCHI, C. CHALLIS, J. CITRIN, G. COLYER, A.C.A. FIGUEIREDO, L. FRASSINETTI, E. JOFFRIN, T. JOHNSON,<br />

E. LERCHE, A.G. PEETERS, A. SALMI, D. STRINTZI, T. TALA, M. TSALAS, D. VAN EESTER, P.C. DE VRIES, J. WEILAND, M. BARUZZO, M.N.A.<br />

BEURSKENS, J.P.S. BIZARRO, P. BURATTI, F. CRISANTI, X. GARBET, C. GIROUD, N. HAWKES, J. HOBIRK, F. IMBEAUX, J. MAILLOUX, V.<br />

NAULIN, C. SOZZI, G. STAEBLER, T.W. VERSLOOT AND JET–EFDA CONTRIBUTORS: A key to improved ion core confinement in the JET<br />

tokamak: ion stiffness mitigation due tocombined plasma rotation and low magnetic shear, 23rd IAEA Fusion Energy Conference (FEC)<br />

Daejon (Korea), October 11–16, 2010<br />

P.A. POLITZER, C.D. CHALLIS, E. JOFFRIN, T.C. LUCE, M. BEURSKENS, P. BURATTI, F. CRISANTI, J.C. DEBOO, J.R. FERRON, C. GIROUD,<br />

J. HOBIRK, C.T. HOLCOMB, A.W. HYATT, F. IMBEAUX, R.J. JAYAKUMAR, I. JENKINS, J.E. KINSEY, R.J. LA HAYE, D.C. MCDONALD, C.C.<br />

PETTY, F. TURCO, M.R. WADE AND JET–EFDA CONTRIBUTORS: Understan<strong>di</strong>ng confinement in advaced inductive scenario plasmas –<br />

dependence on gyrora<strong>di</strong>usand rotation, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

M.P. GRAYAZNEVICH, Y.Q. LIU, T.C. HENDER, D.F. HOWELL, I.T. CHAPMAN, C.D. CHALLIS, S.P. PINCHES, E. JOFFRIN, H.R. KOSLOWSKI, P.<br />

BURATTI, E. SOLANO AND JET–EFDA CONTRIBUTORS: Determination of plasma stability using resonant field amplification in JET, 23rd<br />

IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

X. WANG, S. BRIGUGLIO, G. FOGACCIA, G. VLAD, C. DI TROIA, F. ZONCA, L. CHEN, A. BIERWAGE, H. ZHANG: Kinetic thermal ions effects<br />

on Alfvénic fluctuations in tokamak plasmas, 23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

L. CHEN, W. DENG, Z. LIN, D. SPONG, G.Y. SUN, X. WANG, X.Q.XU, H.S. ZHANG, W.L. ZHANG, A. BIERWAGE, S. BRIGUGLIO, I. HOLOD, G.<br />

VLAD, Y. XIAO, F. ZONCA: Verification of gyrokinetic particle simulation of Alfvén eigenmodes excited by external antenna and by fast ions,<br />

23rd IAEA Fusion Energy Conference (FEC) Daejon (Korea), October 11–16, 2010<br />

ZHIYONG QUI, F. ZONCA, L. CHEN: Kinetic theories of geodesic acoustic mode in toroidal plasmas, 23rd IAEA Fusion Energy Conference<br />

(FEC) Daejon (Korea), October 11–16, 2010


116<br />

progress report<br />

2010<br />

A. BIERWAGE, C. DI TROIA AND THE FRASCATI THEORY GROUP: Method for loa<strong>di</strong>ng marker particles for arbitrary <strong>di</strong>stribution functions<br />

and application forsimulation of high–energy ion dynamics in tokamak plasma, Joint International Conference on Superconducting in<br />

Nuclear Applications (SNA) Tokyo (Japan), October 17–21, 2010<br />

P. COSTA, C. NERI, M. SPAGNOLO, F. MICCHETTI: A software platform for the optimization of IVVS viewing performances, 2010 EnginSoft<br />

International Conference – CAE Technologies for Industry and ANSYS Italian Conference Brescia, Fiera Montechiari (Italy,) October 21–22, 2010<br />

F. BORGONONI, S. TOSTI, C. RIZZIELLO, M. VADRUCCI, N. GHIRELLI, K. LIGER: Multi physic approach for membrane reactor modelling for<br />

wet gas detritiation, 9th International Conference on Tritium Science and Technology (TRITIUM 2010) Nara (Japan), October 24–29, 2010<br />

A. SANTUCCI, F. BORGONONI, C. RIZZIELLO, S. TOSTI: A comparison study of highly tritiated water decomposition processes, 9th<br />

International Conference on Tritium Science and Technology (TRITIUM 2010) Nara (Japan), October 24–29, 2010<br />

D. PACELLA, S. DABAGOV, F. MURTAS, L. GABELLIERI, A. ROMANO, D. HAMPAI, D. MAZON: Polycapillary optics for soft x-ray <strong>di</strong>agnostics<br />

in magnetic fusion plasmas, 4th International Conference on Charged and Neutral Particles Channeling Phenomena (Channeling 2010)<br />

Ferrara (Italy), October 3–8, 2010<br />

M. ANGELONE, P. BATISTONI, F. MORO, M. PILLON, R. VILLARI, M. LOUGHLIN: A Neutronics shiel<strong>di</strong>ng mock–up experiment for reduction<br />

of uncertainty on the pre<strong>di</strong>ction ofthe ITER–TFC nuclear heating, IAEA–ITER Technical Meeting on Analysis of ITER Materials and<br />

Technologies (MIIFED 2010) Montecarlo (Principato <strong>di</strong> Monaco), November 23–25, 2010<br />

E. VISCA, A. PIZZUTO, B. RICCARDI, S. ROCCELLA, G.P. SANGUINETTI: A reliable technology to manufacture the ITER inner vertical target,<br />

IAEA–ITER Technical Meeting on Analysis of ITER Materials and Technologies (MIIFED 2010) Montecarlo (Principato <strong>di</strong> Monaco),<br />

November 23–25, 2010<br />

F. ZONCA, LIU CHEN: Recent progress and future prospects in energetic particle physics in toroidal plasmas, 20th International Toki<br />

Conference (ITC-20) on The Next Twenty Years in Plasma and Fusion Science Toki (Japan) ,November 7–10, 2010<br />

M. PILLON, M. ANGELONE, S. SANDRI: Measurements of the activation and decay heat produced in materials irra<strong>di</strong>ated with D-Tneutrons.<br />

Comparison with easy–2007 code pre<strong>di</strong>ctions, 19th Topical Meeting on Technology of Fusion Energy (TOFE) Las Vegas (USA), November<br />

7–11, 2010<br />

L. DI PACE, D. CARLONI, L. PERNA, S. PACI: Application of pactiter V3.3 code to the ACPS assessment of ITER neutral beam injectors primary<br />

heat transfer system, 19th Topical Meeting on Technology of Fusion Energy (TOFE) Las Vegas (USA), November 7–11, 2010<br />

R. VITELLI, L. BONCAGNI, F. MECOCCI, S. PODDA, V. VITALE, L. ZACCARIAN: An anti–windup–based solution for the low current<br />

nonlinearity compensation on the FTU horizontal position controller, 49th IEEE Conference on Decision and Control Atlanta, GA (USA),<br />

December 15–17, 2010<br />

G. VARANO, L. BONCAGNI, S. GALEANI, G. GRANUCCI, V. VITALE, L. ZACCARIAN: Plasma position and elongation regulation at FTU using<br />

dynamic allocation, 49th IEEE Conference on Decision and Control Atlanta, GA (USA), December, 15–17, 2010<br />

E. BARBATO: The role of collisional absorption in LHCD, 6th IAEA Technical Meeting on Steady State Operation of Magnetic Fusion<br />

Devices Vienna (Austria) December 6–10, 2010<br />

8.2 Workshops and Seminars<br />

Workshops<br />

08–09/03/2010 Task EFDA TA TGS-01–04<br />

16/03/2010 <strong>ENEA</strong>–CEA Meeting<br />

12–14/04/2010 JT60–SA – 8th Technical Committe Meeting (TCM–8)<br />

13–14/04/2010 1st Course on Membranes for Fusion Fuel Cycle<br />

15–16/04/2010 Combined Network Meeting EURATOM Research Training – FUEL CYCLE EFDA Goal Oriented Training<br />

– TRI–TOFFY<br />

07/05/2010 Visita rappresentanti Ambasciata <strong>di</strong> Francia<br />

29/06/2010 HAZOP Meeting<br />

08/07/2010 50° Anniversario dell’Associazione EURATOM–<strong>ENEA</strong> sulla <strong>Fusione</strong><br />

1/10/2010 CEA “CFS2010” <strong>ENEA</strong> Meeting<br />

14/12/2010 PP11 Steering Committee N°2


publications and events (cont’d.)<br />

progress report<br />

2010<br />

117<br />

Seminars<br />

26/01/2010 E. Lazzaro —CNR–IFP, Milano (Italy) (in video-conferenza)<br />

Uno sguardo sulla fisica dei dusty plasmas<br />

27/01/2010 K. Czerski — Institute of Physics, University of Szczecin (Poland); Institut für Optik und Atomare Physik,<br />

Technische Universität, Berlin (Germany)<br />

Enhanced electron screening and nuclear mechanism of cold fusion<br />

08/02/2010 F. Alla<strong>di</strong>o, P. Micozzi, A. Mancuso — <strong>ENEA</strong> Frascati (Italy)<br />

PROTO–SPHERA: Formare e sostenere un toro <strong>di</strong> plasma con un'iniezione <strong>di</strong> elicita' quasi-continua<br />

09/02/2010 G. Sonnino — ULB, Bruxelles (Belgio)<br />

Nonlinear transport and <strong>di</strong>stributions functions in collisional tokamak–plasmas<br />

10/03/2010 A. Jacchia – IFP-CNR, Milano (Italy)<br />

Density response to modulated ECH heating in FTU tokamak<br />

29/03/2010 A.V. Chechkin — Akhiezer Institute for Theoretical Physics National Science Center “Kharkov Institute of<br />

Physics and Technology” and School of Chemistry, Tel Aviv University (Israel)<br />

A few "PARADOXES" of Lévy flights<br />

14/04/2010 Y. Kamada — JAEA, Naka (Japan)<br />

JT–60SA plasma regimes and research plan<br />

19/04/2010 A. Perona — Politecnico <strong>di</strong> Torino (Italy)<br />

Electron response to inertial magnetic reconnection<br />

21/04/2010 P. Martin and the RFX–mod team – Consorzio RFX, Associazione Euratom–<strong>ENEA</strong> sulla <strong>Fusione</strong>, Padova (Italy)<br />

Overview of the RFX fusion science program<br />

07/07/2010 R. Khan – National Tokamak Fusion Program, Islamabad (Pakistan)<br />

Nonlinear simulation of MHD instabilities in tokamak plasmas<br />

24/09/2010 A. Fasoli, I. Furno – CRPP (Svizzera)<br />

Turbulence and transport in simple magnetized toroidal plasmas<br />

29/10/2010 G. Montani – <strong>ENEA</strong> Frascati, ICRANet, Dip. Fisica, Università <strong>di</strong> Roma (Italy)<br />

Plasma features in astrophysical accretion <strong>di</strong>sks<br />

23–25/11/2010 M.C.H. McKubre – Energy Research Center, SRI International, Menlo Park, California (USA)<br />

Techniques applied to stu<strong>di</strong>es of anomalous effects in the palla<strong>di</strong>um–deuterium system: impedance<br />

spectroscopy; resistance ratio measurement; calorimetry 1,2,3<br />

09/12/2010 Jiangang Li – Institute of Plasma Physics, Hefei (China)<br />

Present MCF activities in ASIPP1<br />

8.3 Patents<br />

RM2010U000066 S. TOSTI, F. BORGOGNONI, F. MARINI, A. SANTUCCI, A. BASILE, L. BETTINALI (*)<br />

Dispositivo compatto a membrana in lega <strong>di</strong> Pd per la produzione <strong>di</strong> idrogeno ultrapuro<br />

RM2010A000330<br />

RM2010A000340<br />

S. TOSTI, N. GHIRELLI, F. BORGOGNONI, P. TRABUC, A. SANTUCCI, K. LIGER, F. MARINI<br />

Reattore a membrana per il trattamento <strong>di</strong> gas contenenti trizio<br />

N. GHIRELLI, S. TOSTI, P. TRABUC, F. BORGOGNONI, K. LIGER, A. SANTUCCI, X. LEFEBVRE<br />

Processo per la detriziazione <strong>di</strong> soft housekeeping waste<br />

RM2010A000380 M.S. SARTO, F. SARTO, A. LAMPASI, A. TAMBURRANO, M. D’AMORE (*)<br />

Film sottile per schermi elettromagnetici trasparenti per risparmio energetico<br />

(*) Not in Assocation framework


118<br />

progress report<br />

2010<br />

chapter 9<br />

miscellaneous (*)<br />

(*) Not in Association framework<br />

9.1 The Fleischman&Pons Effect Through the Materials Science<br />

Development<br />

The state of the palla<strong>di</strong>um metal has been identified on the basis of statistical data to play fundamental roles<br />

in producing the Fleischman–Pons excess heat effect. The deuterium loa<strong>di</strong>ng dynamics and its equilibrium<br />

concentration are mostly controlled by the metallurgy; a minimum threshold loa<strong>di</strong>ng (D/Pd ∼ 0.9) is necessary<br />

to observe the excess. The crystallographic orientation is also<br />

correlated with the phenomenon such that mainly oriented<br />

120<br />

samples gave the highest reproducibility. A specific cathode surface<br />

Pout’ (mW)<br />

morphology, identified by means of the power spectral density<br />

80<br />

function, represents an ad<strong>di</strong>tional identified con<strong>di</strong>tion to observe<br />

Pin (mW) the effect.<br />

Power<br />

40<br />

0<br />

0 50000 100000 150000<br />

Time<br />

Figure 9.1 – Excess of power evolution<br />

Materials specimens respecting the characteristics described above<br />

have been used to obtain a transportable reproducibility. Designed<br />

materials giving excess power have been produced, but the<br />

amplitude of the signals and full reproducibility are not yet<br />

achieved. Other features of the material, such as the nature and<br />

content of impurities and defects, seems to be crucial in obtaining<br />

the required palla<strong>di</strong>um characteristics.<br />

Excess of power obtained by using designed materials are shown<br />

in figure 9.1 a and 9.2<br />

Figure 9.2 – Microscopy of the<br />

“designed” Pd Electrode<br />

9.2 Pd–Based Membranes<br />

A wide development of Pd–based membranes and a study of<br />

processes for ultra pure hydrogen production have been<br />

performed [9.1]: particularly, a two-step process consisting of a<br />

tra<strong>di</strong>tional reformer operating at high temperature (700–800 °C)<br />

and a multi–tube membrane module performing the water gas<br />

shift reaction (350–400 °C) has been tested, see figure 9.3. The membrane module consists of 19 Pd–Ag tubes<br />

of <strong>di</strong>ameter 10 mm, length about 270 mm and wall thickness 50–60 μm. Water–ethanol mixtures have been<br />

treated via steam and oxidative reforming by attaining maximum values of hydrogen yield over 90%, which<br />

correspond to about 3.5 NL min –1 of ultra pure hydrogen produced.<br />

A compact Pd membrane module of reduced size and weight for mobile applications has also been designed<br />

and manufactured [9.2]. A special configuration similar to the design of flat–and–frame heat exchanger has


miscellaneous (cont’d.)<br />

progress report<br />

2010<br />

119<br />

been proposed. The Pd–Ag composite membranes have<br />

been produced in form of thin sheets supported over<br />

stainless steel grids and welded to stainless steel frames. The<br />

<strong>di</strong>ffusion wel<strong>di</strong>ng procedure has further been operated in<br />

order to tightly join the Pd–Ag membranes to the stainless<br />

steel frames. The resulting membrane module is very<br />

compact: as an example, a permeator of surface area of<br />

10 m 2 could be about 1000 × 120 × 180 mm in size.<br />

Modelling and testing of membrane reactors using Pd–Ag<br />

thin wall tubes have concerned the investigation of ethanol<br />

steam and oxidative reforming [9.3–9.7] and water gas shift<br />

reaction [9.8]. The tests have highlighted the complete<br />

hydrogen selectivity of the thin wall membranes and their<br />

capability of promoting the reaction conversion beyond the<br />

thermodynamic equilibrium (shift effect of the<br />

membrane) [9.9].<br />

Figure 9.3 – Hydrogen production from ethanol<br />

reforming: experimental apparatus<br />

9.3 AGILE and LOFT<br />

In 2010 the Astrorivelatore Gamma ad Immagini LEggero<br />

(AGILE), the satellite for gamma and x–ray astronomy built<br />

with the contribute of <strong>ENEA</strong>, made two interesting fin<strong>di</strong>ngs<br />

(among other results): it <strong>di</strong>scovered a possible new class of<br />

celestial gamma-ray sources [9.10], and shed new light on the<br />

nature of the terrestrial gamma ray flashes, an intriguing<br />

phenomenon which might have consequences on the safety of<br />

civil aviation [9.11].<br />

The promising performances of a new x–ray detector, designed<br />

in collaboration with <strong>ENEA</strong> Fusion Technology Unit [9.12],<br />

based on silicon drift detectors, have led to the proposal to<br />

“ESA call for a me<strong>di</strong>um–size mission opportunity for a launch<br />

in 2022” of a new satellite, called Large Observatory For x–ray<br />

Timing (LOFT) [9.13], backed by 130 scientists from 16<br />

countries. Thanks to an innovative design and the development<br />

Figure 9.4 – Pictorial view of LOFT, with the six<br />

petals of LAD deployed<br />

of large monolithic silicon drift detectors, the large area detector (LAD) on board of LOFT would achieve an<br />

effective area of ∼12 m 2 (more than one order of magnitude larger than the current spaceborne x–ray


120<br />

progress report<br />

2010<br />

Figure 9.5 – LOFT, with the detectors folded, in the ogive of the<br />

launcher<br />

detectors) in the 2–30 keV range (fig. 9.4). The achievable time–resolution of<br />

its x–ray observations of compact objects would constitute a relevant<br />

<strong>di</strong>agnostic for strong–field gravity and the equation of state of ultra dense<br />

matter. LOFT has been presented in December 2010; to date it has been<br />

selected (with other 13, out of 47 proposals) for further consideration by the<br />

Advisory Structure of the ESA Scientific Programme.<br />

Figure 9.6 – Elecronic equipment for the RF interferometer for helicon<br />

plasma hydrazine<br />

Standard deviation (Deg)<br />

20<br />

10<br />

5<br />

3<br />

1<br />

0.5<br />

0.2<br />

0.1<br />

0.05<br />

0.02<br />

10<br />

implementation and is based on an <strong>ENEA</strong> electronic patent.<br />

9.4 Digital Phase Detector for the RF<br />

Interferometer for Mini Helicon Space Thruster<br />

Within the HPH.com project a RF interferometer has been built for the mini<br />

helicon thruster at the CISAS laboratory (Padua). This interferometer is<br />

capable of detecting a phase variation of 0.3° within the band 0–15 kHz, and<br />

0.06° within the band 0-100 Hz. This instrument has been used to detect the<br />

density of the plasma generated by the thruster (which is a small cylindrical<br />

plasma with 20 mm of <strong>di</strong>ameter) with an error of 4×10 16 m –3 in the band<br />

0–15 kHz, and of 1×10 16 m –3 in the band 0–100 Hz.<br />

20 40 60 80<br />

Attenuation (dB)<br />

Figure 9.7 – Total error (inclu<strong>di</strong>ng the linearity error)<br />

vs attenuation<br />

Commercial analog I/Q detectors for<br />

phase shift measurements introduce an<br />

error not less that 1°, so a de<strong>di</strong>cated phase<br />

detector, with appropriate noise figures<br />

(0.02°), has been developed, tested and<br />

successfully integrated for the RF<br />

interferometer. It is based on a <strong>di</strong>gital<br />

elaboration system that implements a<br />

vector voltmeter working at the frequency<br />

of 100 MHz and measures the complex<br />

components of the signal under test as<br />

compared<br />

The system sends the elaborated data to a<br />

PC, via an ethernet port at a speed of<br />

31thousand measurements per second. On<br />

the PC a GUI able to start receiving is<br />

present, which saves the data and allows<br />

for a preview of decimated data.<br />

Furthermore, the system shows on a 4–line<br />

LCD the value of the module and the<br />

phase instantaneously measured.<br />

The system calculates the quadrature<br />

components, has a fully <strong>di</strong>gital<br />

The advantages of this system are high linearity, high measurement frequency and high noise immunity, see<br />

figure 9.7.


miscellaneous (cont’d.)<br />

progress report<br />

2010<br />

121<br />

References<br />

[9.1] S. Tosti, Int. J. Hydrogen Energy 35, 12650–12659 (2010)<br />

[9.2] S. Tosti, et al., Dispositivo compatto a membrana metallica per la produzione <strong>di</strong> flui<strong>di</strong> gassosi, Domanda <strong>di</strong><br />

brevetto per modello <strong>di</strong> utilità n. RM2010U000066 del 24.04.2010<br />

[9.3] S. Tosti, et al., Asia–Pac. J. Chem. Eng. 5, 207–212 (2010)<br />

[9.4] A. Iulianelli, et al., J. Hydrogen Energy 35, 3159–3164 (2010)<br />

[9.5] A. Santucci, et al., Oxidative steam reforming of ethanol over a Pt/Al 2 O 3 catalyst in a Pd–based membrane<br />

reactor, accepted for publication on Int. J. Hydrogen Energy<br />

[9.6] S. Tosti, et al., L. M. Madeira, Catal. Today 156, 107–117 (2010)<br />

[9.7] S. Tosti, F. Borgognoni, A. Santucci, Int. J. Hydrogen Energy 35, 11470-11477 (2010)<br />

[9.8] S. Tosti, et al., Int. J. Hydrogen Energy 35, 12596–12608 (2010)<br />

[9.9] A. Basile, et al., Adv. Sci. Technol. 72, 99–104 (2010)<br />

[9.10] A. Pellizzoni, et al., Science 327, 663 (2010)<br />

[9.11] M. Marisal<strong>di</strong>, et al., J. Geophys. Res. 15, A00E13, (2010) doi:10.1029/2009JA014502<br />

[9.12] <strong>ENEA</strong> - Unità Tecnica <strong>Fusione</strong>, Progress Report (2009)<br />

[9.13] M. Feroci, et al., LOFT – a Large Observatory For x–ray Timing, Procee<strong>di</strong>ngs of SPIE Vol. 7732, Paper No.<br />

7732–66 (2010); arXiv:1008.1009v1 [astro–ph.IM]


Organization Chart<br />

The activities of the <strong>ENEA</strong> Research Group<br />

are performed in the Nuclear Fusion Unit.<br />

In 2010, a total of 149 professionals and 131<br />

non professionals worked in fusion activities<br />

Euratom–<strong>ENEA</strong><br />

Association<br />

2010annual<br />

fusion<br />

activities


progress report<br />

2010<br />

123<br />

UNITA’ TECNICA FUSIONE<br />

Aldo Pizzuto<br />

Servizio Diffusione Tecnologie<br />

Paola Batistoni<br />

Coor<strong>di</strong>namento Attività<br />

Progetto FAST<br />

Flavio Crisanti<br />

Servizio Supporto Tecnico<br />

Gestionale<br />

Nicola Manganiello<br />

Coor<strong>di</strong>namento Pianificazione<br />

Logistica e Sicurezza<br />

Giovanni Coccoluto<br />

Laboratorio Fisica della <strong>Fusione</strong> a<br />

Confinamento Magnetico<br />

Angelo Tuccillo<br />

Laboratorio <strong>Fusione</strong> Inerziale<br />

Aldo Pizzuto a.i.<br />

Laboratorio Gestione Gran<strong>di</strong> Impianti Sperimentali<br />

Giuseppe Mazzitelli<br />

Laboratorio Ingegneria Elettrica ed Elettronica<br />

Giuseppe Mazzitelli a.i.<br />

Laboratorio Tecnologie Nucleari della <strong>Fusione</strong><br />

Aldo Pizzuto a.i.<br />

Laboratorio Superconduttività<br />

Antonio della Corte<br />

December, 2010


Abbreviation and Acronyms<br />

A<br />

ac<br />

ACCC<br />

ACP<br />

ADC<br />

AE<br />

AES<br />

AGILE<br />

APD<br />

Asdex–U<br />

B<br />

BA<br />

BAE<br />

BgB<br />

BP<br />

C<br />

alternating current<br />

active correction and compensation coils<br />

activated corrosion product<br />

analog–<strong>di</strong>gital converter<br />

Alfvén eigenmode<br />

Auger electron spectroscopic<br />

Astrorivelatore Gamma ad Immagini<br />

LEggero<br />

avalanche photo<strong>di</strong>ode<br />

Axially Symmetric Divertor EXperiment<br />

Upgrade – Garching (Germany)<br />

Broader Approach<br />

beta–induced Alfvén eigenmode<br />

Bohm–gyroBohm<br />

backplate<br />

Euratom–<strong>ENEA</strong><br />

Association<br />

2010annual<br />

fusion<br />

activities<br />

CB<br />

cassette body<br />

CC<br />

coated conductors<br />

CCD charge–coupled device<br />

CD<br />

current drive<br />

CEA Commissariat à l’Energie Atomique –<br />

Cadarache (France)<br />

CFC<br />

carbon/carbon fibre composite<br />

CGM critical gra<strong>di</strong>ent model<br />

CICC cable–in–conduit conductor<br />

CNR<br />

Consiglio Nazionale delle Ricerche (Italy)<br />

(National Research Council)<br />

CNS compact neutron spectrometer<br />

CPOs Consistent Physical Objects<br />

CRP<br />

Coor<strong>di</strong>nate Research Project<br />

CRPP Centre de Recherches en Physique des<br />

Plasmas – Villigen (Switzerland)<br />

CS<br />

central solenoid<br />

CTS<br />

collective Thomson scattering<br />

CVCS chemical volume control system<br />

CW<br />

continuous wave<br />

D<br />

DACs<br />

data acquistion systems


abbreviation and acronyms (cont’d.)<br />

progress report<br />

2010<br />

125<br />

DEMO<br />

DPRW<br />

DPSD<br />

demonstration/prototype reactor<br />

dynamic polarization random walk<br />

<strong>di</strong>gital pulse shape <strong>di</strong>scrimination<br />

E<br />

EAE<br />

EBBTF<br />

EC<br />

ECCD<br />

ECE<br />

ECH<br />

ECRH<br />

EFDA<br />

EGAM<br />

ELITE<br />

ELM<br />

EM<br />

EMOBC<br />

EO<br />

EPs<br />

EPMS<br />

ESRF<br />

ETG<br />

ETS<br />

EVEDA<br />

EXAFS<br />

ellipticity–induced Alfvén eigenmode<br />

European Bree<strong>di</strong>ng Blanket Test Facility<br />

electron cyclotron<br />

electron cyclotron current drive<br />

electron cyclotron emission<br />

electron cyclotron heating<br />

electron cyclotron resonance heating<br />

European Fusion Development Agreement<br />

energetic–particle–induced GAM<br />

EVEDA LIthium Test Experiment<br />

edge localized mode<br />

electromagnetic<br />

electromagnetic model of the buil<strong>di</strong>ng complex<br />

electro–optical<br />

energetic particles<br />

energetic particle MODES<br />

European Synchrotron Ra<strong>di</strong>ation Facility – Grenoble (France)<br />

electron temperature gra<strong>di</strong>ent<br />

European Transport Solver<br />

Engineering Validations and Environmental Engineering<br />

Design Activities<br />

extended x–ray absorption fine structure<br />

F<br />

FAST<br />

FEMs<br />

FF<br />

F4E<br />

FLR<br />

FMW<br />

FNG<br />

FOW<br />

FPGA<br />

FTU<br />

FW<br />

FWHM<br />

Fusion Advanced Stu<strong>di</strong>es Torus<br />

finite element models<br />

For Fusion<br />

Fusion For Energy<br />

finite Larmor ra<strong>di</strong>us<br />

fast magneto–sonic waves<br />

Frascati Neutron Generator – <strong>ENEA</strong> (Italy)<br />

finite orbit width<br />

field programmable gate array<br />

Frascati Tokamak Upgrade – <strong>ENEA</strong> (Italy)<br />

first wall<br />

full width at half maximum<br />

G<br />

GAM<br />

geodesic acoustic mode


126<br />

progress report<br />

2010<br />

GEM<br />

GRS<br />

GSEP<br />

H<br />

HAZOP<br />

HEFUS<br />

HFTM<br />

HYMAGYC<br />

HMGC<br />

HPC–FF<br />

HRNS<br />

HRP<br />

HRTS<br />

HTS<br />

HTW<br />

HV<br />

I<br />

IAEA<br />

IBW<br />

IC<br />

ICRANet<br />

ICRF<br />

ICRH<br />

IELLLO<br />

IFMIF<br />

IFP<br />

IFTS<br />

ILO<br />

ILW<br />

IMP<br />

INFN<br />

gas electron multiplier<br />

gamma ray spectroscopy<br />

gyrokinetic simulation of energetic<br />

particle turbulence and transport<br />

hazard and operability<br />

HElio for FUSion<br />

high flux test module<br />

new hybrid magnetohydrodynamic<br />

gyrokinetic code<br />

hybrid magnetohydrodynamic<br />

gyrokinetic code<br />

High Performance Computing For<br />

Fusion<br />

high resolution neutron<br />

spectromete<br />

hot ra<strong>di</strong>al pressing<br />

high resolution Thomson<br />

scattering<br />

high–temperature superconductor<br />

highly tritiated water<br />

high voltage<br />

International Atomic Energy Agency<br />

– Vienna<br />

ion Bernstein waves<br />

ion–cyclotron<br />

International Center for Relativistic<br />

Astrophysics Network (Italy)<br />

ion–cyclotron resonance frequency<br />

ion cyclotron resonance heating<br />

Integrated European Lead Lithium<br />

LOop<br />

International Fusion Materials<br />

Irra<strong>di</strong>ation Facility<br />

Institute of Plasma Physics – CNR<br />

Milan (Italy)<br />

Institute for Fusion Theory and<br />

Simulation, Zhejiang University –<br />

Hangzhou (China)<br />

Industrial Liaison Officer<br />

ITER like wall<br />

Integrated Modelling Project<br />

National Institute of Nuclear<br />

Physics (Italy)<br />

IO<br />

IOS<br />

IPP<br />

ISP<br />

ISTTOK<br />

ITB<br />

ITER<br />

ITG<br />

ITG<br />

ITM<br />

ITPA<br />

IVT<br />

IVVS<br />

J<br />

JAEA<br />

JET<br />

JT–60SA<br />

K<br />

ITER Organization<br />

Integrated Operation Scenario<br />

Max–Planck–Institut für<br />

Plasmaphysik – Garching<br />

inner strike point<br />

Istituto Superior Técnico Tokamak<br />

internal transport barrier<br />

“the way” in latin<br />

ion turbulent gra<strong>di</strong>ent<br />

ion temperature gra<strong>di</strong>ent<br />

Integrated Tokamak Modelling<br />

International Tokamak Physical<br />

Activity<br />

inner vertical target<br />

in–vessel viewing system<br />

Japan Atomic Energy Agency<br />

Joint European Torus – Abingdon<br />

(UK)<br />

Japan Tokamak 60 Super<br />

Advanced<br />

KGAM kinetic GAM<br />

KIT Karlsruhe Institute of Technology –<br />

Karlsruhe (Germany)<br />

KTH Royal Institute of Technology –<br />

Stockholm (Sweden)<br />

L<br />

LAD<br />

LCMS<br />

LCOs<br />

LCQ<br />

LFS<br />

LH<br />

LHCD<br />

LLL<br />

LNF<br />

LOFT<br />

LOS<br />

large area detector<br />

last closed magnetic surface<br />

limiting con<strong>di</strong>tions for operations<br />

linear current quench<br />

low field side<br />

lower hybrid<br />

lower hybrid current drive<br />

liquid lithium limiter<br />

INFN - Frascati National Laboratory<br />

(Italy)<br />

Large Observatory For x–ray<br />

Timing<br />

line of sight


abbreviation and acronyms (cont’d.)<br />

progress report<br />

2010<br />

127<br />

LOVA<br />

LTC<br />

LTCC<br />

LTS<br />

M<br />

MARTe<br />

MCNP<br />

MDT<br />

MDTNS<br />

MFG<br />

MFP<br />

MFRS<br />

MHD<br />

MiAE<br />

MiEAE<br />

MiKAE<br />

MiUR<br />

MOD<br />

MSE<br />

MTLs<br />

MUT<br />

N<br />

NBI<br />

NES<br />

NICD<br />

NMC<br />

NNBI<br />

NPM<br />

NTM<br />

O<br />

OSP<br />

loss of vacuum accident<br />

Large Tokamak Cooperation<br />

low temperature co–fired ceramic<br />

low–temperature superconducting<br />

multi–threated application real–time<br />

executor<br />

Monte Carlo n–Particle<br />

routine maintenance days<br />

not–scheduled mean down time<br />

motor flywheel generator<br />

magnetic fusion plasmas<br />

magnetic field reduction system<br />

magnetohydrodynamic<br />

magnetic island induced Alfvén<br />

eigenmode<br />

magnetic island eccentricity<br />

induced Alfvén eigenmode<br />

magnetic island kinetic induced<br />

Alfvén eigenmode<br />

Ministero dell’Università e della<br />

Ricerca<br />

metal–organic deposition<br />

motional Stark effect<br />

main transmission lines<br />

mean up time<br />

neutral beam injection<br />

neutron emission spectroscopy<br />

non inductive current driven<br />

new manifold concept<br />

negative neutral beam injection<br />

neutron profile monitor<br />

neoclassical tearing modes<br />

outer strike point<br />

PERMCAT<br />

PF<br />

PFC<br />

PFU<br />

PHSC<br />

PHTS<br />

PI<br />

PTB<br />

PW<br />

Q<br />

QMS<br />

R<br />

rf<br />

RH<br />

RNC<br />

RWM<br />

S<br />

SAW<br />

Sci–DAC<br />

SD<br />

SEM<br />

SiC<br />

SNR<br />

SOC<br />

SOL<br />

SSFPQL<br />

ST<br />

SXR<br />

T<br />

permeator catalyst<br />

poloidal field<br />

plasma–facing component<br />

plasma–facing unit<br />

Programmable High Speed<br />

Controller<br />

primary heat transfer system<br />

parametric instability<br />

Physikalisch–Technische<br />

Bundesanstalt – Braunschweig<br />

(Germany)<br />

plasma wall<br />

Quality Management System<br />

ra<strong>di</strong>ofrequency<br />

remote handling<br />

ra<strong>di</strong>al neutron camera<br />

resistive wall modes<br />

shear Alfvén wave<br />

Scientific Discovery through<br />

Advanced Computing – USA<br />

slowing down<br />

scanning electron microscopy<br />

silicon carbide<br />

signal to noise ratio<br />

self–organized criticality<br />

scrape–off layer<br />

steady state Fokker Planck quasi<br />

linear<br />

sawteeth<br />

soft–x–ray<br />

P<br />

PAM<br />

PBC<br />

passive–active multijunction<br />

pre–brazed casting<br />

TAE<br />

TAs<br />

TBM<br />

TDS<br />

TEM<br />

toroidal Alfvén eigenmode<br />

task agreements<br />

test blanket module<br />

time–domain spectroscopy<br />

trapped electron mode


128<br />

progress report<br />

2010<br />

TF<br />

TF<br />

TFC<br />

TFR<br />

TFSC<br />

TG<br />

TORIC<br />

TP<br />

TRIEX<br />

U<br />

UCI<br />

UT<br />

UTFUS<br />

UTS<br />

V<br />

VDE<br />

VF<br />

Task Force<br />

toroidal field<br />

toroidal field coils<br />

toroidal field ripple<br />

toroidal field superconductor coil<br />

Topical Group<br />

toroidal ion cyclotron<br />

twist pitch<br />

tritium extraction<br />

University of California – Irvine<br />

(Usa)<br />

ultrasonic technique<br />

<strong>ENEA</strong> - Unità Tecnica <strong>Fusione</strong><br />

ultimate tensile strength<br />

vertical <strong>di</strong>splacement events<br />

void fraction<br />

VHFS<br />

VNA<br />

VPCE<br />

VPI<br />

VS<br />

VS<br />

VUV<br />

VV<br />

W<br />

WW<br />

X<br />

XHMGC<br />

XPS<br />

XRD<br />

XSC<br />

vertical high field side<br />

vector network analyzer<br />

vapor phase catalytic exchange<br />

vacuum pressure impregnation<br />

vertical system<br />

vertical stabilizing<br />

visible ultraviolet<br />

vacuum vessel<br />

wet win<strong>di</strong>ng<br />

eXtended hybrid<br />

magnetohydrodynamic gyrokinetic<br />

code<br />

x–ray photoelectron spectroscopy<br />

x–ray <strong>di</strong>ffraction<br />

extreme shape control

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