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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 />
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[1.72] P. Bak, C. Tang, and K. Wiesenfeld, Phys. Rev. Lett. 59, 381 (1987)<br />
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[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
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[1.81] F. Zonca and L. Chen, Phys. Fluids B 5, 3668, (1993)<br />
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[1.85] M. Brambilla, Nucl. Fusion 34, 1121 (1994)<br />
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[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 />
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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 />
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[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 />
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experimental results, Presented at the 26th Symposium on Fusion Technology (SOFT) (Porto 2010), to appear<br />
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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 />
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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
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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 />
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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 />
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20<br />
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D:\Lavoro\ULTRASUONI\CAMPIONE01ULTRAN\ultime provecd<br />
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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 />
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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 />
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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.
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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
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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.
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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
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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
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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 />
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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 />
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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 />
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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