School report (Butterfly design) - Ciemat

Asociación EURATOM CIEMAT para FusiónAnnual Report 2012

INDEXINTRODUCTION 111 PROVISION OF SUPPORT TO THE ADVANCEMENT OF THE ITER PHYSICSBASIS 131.1 Development of candidate operating scenarios 131.1.1 ELM physics and control 131.1.1.1 ELM studies in JET with visible Fast Camera. 131.1.1.2 The effect of ELM pacing via vertical kicks on the access to stationary H-mode with good confinement (H 98 ~1) on JET 131.1.2 contribution to JET results in view of ITER operation 141.3 Energy and particle confinement and transport 141.3.1 L-H physics 141.3.1.1 Characterization of the dynamical coupling between flows andfluctuations in different magnetic configurations (q scan) during the L-H transition in TJ-II.141.3.2 Momentum transport 151.3.2.2. Damping mechanisms of flows: 151.3.2.3 Driving mechanisms of zonal flows: 151.3.2.4 Electromagnetic turbulence and Maxwell stresses 161.3.3 Impurity transport studies 161.3.3.1 See 3.1.3.1 171.3.4 Isotope effect 171.3.4.1 Report on the impact of the isotopic effect on plasma confinement (H / D)and amplitude of long-range correlations (zonal flows) 171.4 MHD stability and plasma control 171.4.1 ELM physics 171.4.1.1 Electromagnetic turbulent structures 171.4.1.2 Determination of plasma stability using resonant field amplification in JET17

1.4.2 Plasma control 181.5 Power and particle exhaust. Plasma-wall interaction 181.5.1 Deposition in gaps and thermo-oxidation by NO 2 181.5.2 Activities oriented to the validation of Li as a PFC for a Fusion reactor 191.5.3 Reduction of the sputtering yield of W by in-situ nitriding 191.5.4 Edge transport and particle and impurity source 191.5.4.1 Radial plasma transport and recycling of neutrals. 191.6 Physics of plasma heating and current drive 191.6.1 Dependence of plasma fluctuations on RF stray radiation 191.7 Energetic particle physics 201.7.1 Fast ion studies. 201.7.2 Alfvén eigenmode properties 201.7.3 Effect of ECH application on Alfvén Eigenmodes activity 201.8 Theory and modelling for ITER and DEMO 211.8.1 Plasma Heating (NBI) 211.8.2 Computational Developments 212 DEVELOPMENT OF PLASMA AUXILIARY SYSTEMS 222.1 Heating and current drive systems 222.1.1 Electron Bernstein Waves Heating experiments in TJ-II 222.1.2 NBI heating studies: Ion trajectory calculation 222.1.3 ECH activities in TJ-II 222.1.3.1 Changes in the gyrotron radiation properties, induced by a small amountof reflected modulated power. 222.1.3.2 Second harmonic X mode breakdown experiments. 232.2 Plasma Diagnostics 232.2.1 Development of plasma diagnostics in TJ-II 232.2.1.1. Calibration of the multi-foil soft x-ray diagnostic (M4F) for core electrontemperature estimations. 232.2.1.2 Ion temperature measurements based on atomic beam measurementsand RFA diagnostic developed by IST. 23Asociación Euratom – CIEMAT .- Annual Report 2012 2

3.5.1 Engineering activities 413.5.1.1 Activities in the TJ-II experiment 413.5.1.1.1 Technical operation of TJ-II 413.5.1.1.2 Maintenance and upgrading of systems and components 423.5.1.1.3 Installation of new equipment 443.5.2 Operation of TJ-II 453.5.2.1 Operation of the ECH system 473.5.2.1.1 General maintenance and improvements tasks 473.5.2.1.2 Experimental characterization 473.5.2.2 Operation of the NBI heating system 473.5.2.2.1 NBI operation 473.5.2.2.2 Ion Source conditioning 493.5.2.2.3 NBI Maintenance 493.5.2.2.4 NBI Upgrades 514 EMERGING TECHNOLOGIES 554.1 Development of material science and advanced materials for DEMO 554.1.1 Functional materials 554.1.1.1 Production of advanced Li silicates 554.1.1.2 Ion radiation evaluation of Li ceramics 554.1.1.3 Corrosion and compatibility of Li silicates 574.1.2 Ceramic insulators 584.1.2.1 Radiation evaluation of silica glasses 584.1.2.2 Ionoluminescence characterization of light ions on insulator materials 584.1.2.3 Characterization of H and He on insulating surfaces 594.1.2.4 Radiation effects on magnetic sensors and cables 594.1.2.5 Radiation effects on other IR/VIS diagnostics components 604.1.2.6 Definition of materials requirements in DEMO: ceramic insulators 604.1.3 Nanostructured ODS ferritic steels development (ODSFS Task Agreement) 604.1.3.1 Microstructural characterization of ODS/FeCr alloys 604.1.3.2 Radiation effects on ODS steels 62Asociación Euratom – CIEMAT .- Annual Report 2012 5

4.1.3.3 Production and characterization of ODS steels 634.1.4 Tungsten and Tungsten Alloys Development (WWALLOY Task Agreement)654.1.4.1 Brazing development 654.1.4.2 W-V and W-Ti ODS alloys development 664.1.4.3 ODS W-TiC and W-Ti alloys development 674.1.4.4 Oxidation resistant W-alloys development 694.1.5 Nanostructured ODS and no-ODS Cu based materials development (HighHeat Flux Materials Task, HHFMAM Agreement) 704.1.6 SiC materials 714.1.6.1 Production of SiC/SiC low termal conductivity composites for DCLLapplications 714.1.6.2 Characterization of SiC materials for DEMO 724.2 Materials modelling 724.2.1 Radiation Effects Modelling and Experimental Validation (REMEV TaskAgreement) 724.2.1.1 Rate Theory modelling of He evolution and its interaction withmicrostructure in Fe 724.2.1.2 Synergetic effects of H and He in Fe 734.2.1.3 Experiments for modelling validation: He desorption in Fe and othermodel materials 744.2.1.4 Experiments for modelling validation: Resistivity measurements 754.2.2 Modelling of insulator and functional materials 754.2.2.1 H in diamond 754.2.3 Plasma Wall materials modelling 754.2.3.1 Rate Theory modelling of defect evolution in irradiated W 754.2.3.2 Modelling of neutron irradiation effects on W 764.2.4 Radiation effects code improvement and development 774.2.4.1 Methodology for PKA evaluation 774.2.4.2 Tools for MCNP and CAD interfacing 774.2.4.3 Development of coupled radiation transport and activation calculations 784.3 Techniques for controlling tritium inventory 78Asociación Euratom – CIEMAT .- Annual Report 2012 6

4.3.1 Tritium modelling 784.3.1.1 Tools development for tritium plant modelling 784.3.1.2 LIBRETTO irradiation modelling 794.3.1.3 Developing of a facility for the validation of a permeator against vacuum794.3.1.4 Design and manufacture of a vacuum-permeator prototype 804.4 Development of HT superconductors for DEMO 804.4.1 Assessment for RE-123 fusion cable joints 804.5 Fusion Safety issues 814.5.1 Neutronics 814.5.1.1 Radiation and dose mapping evaluation of DEMO of Blanket activation 814.5.1.2 Neutronic study to shield the upper vertical port of DEMO 814.5.1.3 Evaluation of radiation load at TF coils 824.5.1.4 Evaluation of Blanket activation 824.5.1.5 Neutronic and activation assessments of a DCLL DEMO model 834.5.2 Balance of Plant related issues 844.5.2.1 Development of a LiPb-Supercritical CO2 heat exchanger 844.5.2.2 Energy Storage requirements for a pulsed fusion power plant 844.5.2.3 Electrical power output requirements of a fusion power plant 854.5.2.4 Electrical power output Nuclear Fusion Safety and Environment:Modeling HT and HTO transport in the Atmosphere 864.6 Remote handling and RAMI 874.6.1 RAMI design guidelines for fusion facilities 874.6.1.1 RAMI activities for DEMO 874.6.2 Remote Handling (RH) 884.6.2.1 Innovative methods for pipe flange joining/separation by brazing andassociated testing technologies 884.6.2.2 Evaluation of dose rate during shutdown periods 894.6.2.3 Design of interface between UPP and tools for UPP RH operation forITER 895 TRAINING, PUBLIC INFORMATION AND SERF 91Asociación Euratom – CIEMAT .- Annual Report 2012 7

5.1 Training 915.1.1 ERASMUS MUNDUS Educational activities (Master and PhD programmes).915.1.2 Goal oriented training: 915.1.3 EFDA Fellowships: 925.1.4 Technofusion Summer Course. 925.1.5 Other training activities 925.2. Public Information 925.3. Technology transfer 925.4. Socioeconomics Studies for Fusion 925.4.1 EFDA Times Model 925.4.2 Public perception of Fusion research 935.4.2.1 Public Discourse about Nuclear Energy before and after Fukushimaaccident (WP12-SER-ACIF-1) 936 OTHER ACTIVITIES CONTRIBUTING TO THE EURATOM FUSION PROGRAMME946.1 Activities related to the Broader Approach 946.1 1 IFMIF/EVEDA Project 946.1.1.1 Introduction 946.1.1.2 Accelerator Facilities: RF system 946.1.1.3 Accelerator Facilities: Beam Dump & HEBT 956.1.1.4 Accelerator Facilities: Diagnostics 976.1.1.5 Accelerator Facilities: DTL & MS 986.1.1.6 Accelerator Facilities: Safety and Radioprotection 996.1.1.7 Test and Target activities: RH Engineering 1016.1.1.8 Test and Target activities: Medium Flux modules engineering 1026.1.1.9 Test and Target activities: Low Flux module 1036.4.1.10 Test and Target activities: Start-up Monitoring Module 1036.1.1.11. Design Integration: Safety 1036.1.1.12. Design Integration: RAM evaluation 104Asociación Euratom – CIEMAT .- Annual Report 2012 8

6.1.1.13. Neutronics study for the installation of the LBVM in the medium fluxarea of IFMIF 1066.1.2. JT-60 SA Cryostat 1066.1.2.1. Activities in the Broader Approach. The Cryostat for JT-60SA 1066.1.3. DEMO R&D 1076.1.3.1. SiC/SiC characterization 1076.1.3.2. Insulators ceramics 1086.2. Dual Coolant Breeder Blankets Programme 1086.2.1. Overview of Tecno_Fus project 1086.2.2. Tecno_Fus DCLL Breeder Blanket design 1096.2.3. Tecno_Fus Neutronics studies 1096.2.4 Tecno_Fus Auxiliary systems development 1096.2.5.Tecno_Fus MHD simulations and assessment 1106.2.6. Tecno_Fus Tritium modelling 1106.2.7. Tecno_Fus development of material production and characterization 1106.3. Fusion Technology Facilities 1116.2.1. Operation of presently available facilities 1116.2.1.1. Operation of the van de Graaf accelerator 1116.2.1.2. Operation of the “Nayade” irradiation facility 1116.2.1.3. Irradiation line at the CMAM ion accelerator 1126.2.1.4. Permeation and diffusivity facility at UPV 1126.2.2. TechnoFusión 1126.2.2.1. Introduction 1126.2.2.2. Irradiation methods 1146.2.2.3. Plasma-Wall Interaction 1166.2.2.4. Characterization Techniques 1166.2.2.5. Liquid Metal technologies 1186.2.2.6. Remote Handling 1186.2.2.7. Simulation Techniques 1196.2.3. IFMIF (outside of the Broader Approach Agreement) 120Asociación Euratom – CIEMAT .- Annual Report 2012 9

6.2.3.1. Use of IFMIF/EVEDA facilities for materials development 1206.2.3.2. Comparison of different irradiation facilities 1217 INERTIAL CONFINEMENT FUSION, KEEP IN TOUCH ACTIVITIES 1227.1. Scientific development in target design 1227.1.1 Radiation hydrodynamics and Atomic Physics 1227.2. Physics and Technology IFE (and MFE) systems 1237.2.1. State of the Art Inertial Fusion Energy by Laser 1237.2.2. Materials advanced under Irradiation and Chamber Dynamics for IFE 1247.2.3. IFE Systems: Reaction Chamber, Safety and Radio Protection 129Asociación Euratom – CIEMAT .- Annual Report 2012 10

INTRODUCTIONThis report describes the activity of the EURATOM-CIEMAT Association during2012 and it is organized following mostly the scheme of the 2012 work program annexed to theassociation contract.The Association has continued its effort in generating a strong fusion technologyprogramme, which is reported in chapters 4 and 6 but this is accompanied with a solidprogramme on plasma physics, oriented in two main lines:a.- Plasma physics developments of general application and of interest for thetokamak and ITER and results obtained in stellarators as test bench to understand tokamakproblems from an advantageous point if view. This is a very important contribution of the TJ-IIexperiment, and example being the slower L-H transition, which allows for a very detailed studyof the mechanisms driving the transition. Chapter 1 shows a number of contributions which aredirectly related to specific ITER problems: L-H transition physics, momentum transport, impuritytransport, fast particle physics, Tritium retention and extraction, role of nitrogen on W sputteringreduction, carbon transport and deposition.b.- Contributions to the development of the stellarator as a candidate for the steadystate reactor. The specific stellarator physics results are reported on Chapter 3: impuritytransport, role of fast particles, confinement transitions, confinement scaling and installation andoperation of a liquid lithium limiter. This chapter also includes the theory developments forstellarators: design of reactor relevant stellarator configurations, island dynamics, neoclassicaltransport, and advanced data analysis techniques applied to TJ-II. Details of the operation andimprovement of engineering TJ-II systems are also reported in chapter 3.Chapter 3 covers also general theory developments, including gyrokinetic theory orprobabilistic transport, as well as theory for heating and diagnostic systems.Another strong point of the TJ-II activity has been historically the development ofauxiliary systems, in particular diagnostics. Those activities are reported on chapter 2 and theycover the development of new x ray diagnostics, the installation of the second Heavy Ion BeamProbe, the new double pulse system for Thomson Scattering and the Diagnostic NBI.International collaboration is mainly devoted to the joint experiment JET, W7X . JETresults are mainly reported in chapter 1: operation regimes, pedestal and ELM studies anddisruption prevention (this part reported on section 2.2). Other international collaborations arerelated to the development of diagnostics, interferometry, for W7X (chapter 3) or the plasmacontrol techniques for TCV.Emerging technologies is one of the areas of growing interest at the Association.Chapter 4, section 4.1, includes a broad description of experimental activity, with lines ofdevelopment on: functional materials, insulators, structural metallic materials like tungsten andAsociación Euratom – CIEMAT .- Annual Report 2012 11

ODS alloys, structural and functional SiC. Modelling activities, devoted to radiation effectsmodelling and validation, insulators behaviour, effects on tungsten and activation phenomenareal also a growing area and they are extensively reported in section 4.2.This chapter shows also the increasing level of activity in the area of Power PlantPhysic and Technology, with new lines of participation, including: high temperaturesuperconductors, remote handling, RAMI analysis, nuclear safety for Fusion, system codedesign, neutronics studies, energy storage, efficient thermal cycles, tritium inventory control andblanket technologies (the later mainly reported on chapter 6)Chapter 5 describes training activities, focused on the Erasmus Mundus Master inFusion Physics and Technology, The European Doctoral College in Fusion and the participationin Goal Oriented training systems: blankets (EUROBREED), remote handling (GOT-RH) andtwo new projects, related to neutronics for diagnostics and materials modelling. Also in chapter5 we include activities on public information, technology transfer and Socioeconomic studies,which for 2012 were concentrated on the further development of the EFDA Times model andthe public perception of Fusion energy.Chapter 6 describes, the IFMIF, JT60 and DEMO activities in the framework of theBroader Approach (only for information) and also the emerging activity in dual coolant blanketdevelopment as well as the experimental fusion technology facilities which form part of the“Technofusion “ project.Finally Chapter 7 describes the Keep in Touch activity on Inertial Fusion.Asociación Euratom – CIEMAT .- Annual Report 2012 12

vertical excursions similar to those obtained in JET at a maximum frequency of 20-30 Hz couldbe delivered with the existing internal VS coil system during the current ramp up/down phase(with I p below 10 MA), which opens up the possibility of using vertical kicks as a tool for ELMfrequency control in ITER. Nevertheless, extrapolation of the JET results to the ITER conditionsis difficult as long as the mechanism for the triggering of the ELMs is not better understood. Onthis topic, a substantial progress has been made on the capability to model the underlyingphysics involved in the kick-triggered ELM. The initial results of the simulations suggest that themechanism by which vertical kicks trigger ELMs is strongly linked to edge currents and theireffect on edge stability. We must, however, wait for the more accurate closed-coupledsimulations to confirm this hypothesis. A positive trend for the kick probability to trigger an ELMwith increasing edge T e is deduced from the modelling (at lower edge resistivity the inducededge current increases faster) and confirmed experimentally, which is encouraging in view ofITER. Further modelling and experimental work are needed to improve the predictive capabilityof a physics basis model of the ELM triggering mechanism via vertical kicks [JET_ELMs delaLuna].1.1.2 CONTRIBUTION TO JET RESULTS IN VIEW OF ITER OPERATIONIn the last time, JET has been in operation with a programmatic focus on thequalification of ITER operating scenarios, on the contribution to ITER design and thepreparation of for plasma confinement with the ITER-like Wall, which is being installedpresently. Good progress has been achieved, including stationary ELMy H-mode operationat 4.5 MA and high triangularity. Particularly, Edge localized mode (ELM) control studiesusing external n = 1 and n = 2 perturbation fields have been performed. Complete ELMsuppression has, however, not been observed, even with an edge Chirikov parameterlarger than 1 [Romanelli-NF].1.3 ENERGY AND PARTICLE CONFINEMENT AND TRANSPORT1.3.1 L-H PHYSICS1.3.1.1 CHARACTERIZATION OF THE DYNAMICAL COUPLING BETWEEN FLOWS ANDFLUCTUATIONS IN DIFFERENT MAGNETIC CONFIGURATIONS (Q SCAN) DURING THE L-HTRANSITION IN TJ-II.In TJ-II experimental evidence supporting the central role of zonal flows has beenobserved in experiments performed close to the L-H transition threshold conditions. A couplingbetween flows and turbulence is found which reveals a characteristic predator-prey behaviour.During the 2012 experimental campaign in TJ-II, dedicated experiments have beencarried out to investigate the spectral structure of the turbulence-flow interaction during thepredator- prey process. The comparison between maxima and minima of the density fluctuationlevel measured during the intermediate oscillatory phase shows a rather well defined wave-Asociación Euratom – CIEMAT .- Annual Report 2012 14

either after L–H transition or after long ELM-free periods during a pulse. These observationsconfirm that the measured increase in the RFA in some cases (e.g. at low beta) may reflect aproximity to stability thresholds, different from the no-wall beta limit associated with the RWM.The first results on n = 2 probing on JET are presented [Gryaznevich_NF_2012].1.4.2 PLASMA CONTROLWork on plasma internal inductance control in tokamaks using electromagneticinduction [(1_3_2_1), (1_3_2_2), (1_3_2_3)] has continued to incorporate new observers forplasma inductance and plasma geometry based on current tomography methods, which involveonly linear operations and are then most suitable for real time implementation. These observershave been validated with actual TCV tokamak data and they have also been used to performmagnetic sensor optimization studies [(1_3_2_4)]. The design work is now moving towards thesimultaneous control of plasma current and inductance using just the electromagnetic inductionavailable from the tokamak transformer (under-actuated system).New robust control designs based on sliding mode control methodology have beenperformed using a model valid for the JET tokamak, testing the performance with numericalsimulations [(1_3_2_5)].A new Rogoswki coil sensor has been installed in the TJ-II stellarator in view of a futureplasma current control system that would extend the present functionality of the magneticconfiguration sweeping capability.1.5 POWER AND PARTICLE EXHAUST. PLASMA-WALL INTERACTION1.5.1 DEPOSITION IN GAPS AND THERMO-OXIDATION BY NO 2A new setup was used to investigate the deposition of eroded carbon at thebottom of the 1mm gaps with depths from 5 to 20 mm. Toroidal and poloidal transport wasinvestigated by exposing a graphite bar to the plasma. Two levels of insertion led to a strongchange of sample temperature, allowing for the discrimination between chemically sputtered (athigh T) and physical sputtered sources. AES and SIMS were used to characterize the depositsin the gap at the JSI in Liubliana. While physical sputtering leads to line-of-sight transport,dominated by simple geometrical constrains, chemically eroded carbon produces a muchbroader pattern.Experiments have been carried out in collaboration with the Toronto UTIAS team for thethermo-oxidation of carbon tiles from DIII-D by NO 2 and its comparison with more conventionalO 2 at several temperatures and pressures. Measurements of D contents by LID, NRA and massspectrometry were addressed [NO2 PSI-12]. No clear evidence of water formation during theremoval of the co-deposits by oxidation by NO 2 has been found yet. The enhancement in theremoval rate of C and D observed in Ciemat when O 2 is replaced by NO 2 was confirmed by theToronto group, but the situation seems to revert at high temperatures (400º), perhaps due to thedecomposition of NO 2 in hot elements.Asociación Euratom – CIEMAT .- Annual Report 2012 18

1.5.2 ACTIVITIES ORIENTED TO THE VALIDATION OF LI AS A PFC FOR AFUSION REACTORSeveral experiments about the compatibility of lithium elements with a hot plasma werecarried out during 2012. First, the lithium liquid limiter (LLL) was exposed to the plasma atseveral temperatures (up to 400ºC) and degrees of insertion into the plasma (up to 3 cm insidethe SOL) with good performance. In addition, a lithium bar (solid) was inserted at several levelsand the I/V characteristics were recorded. Emission of Li and Li+ were also recorded near thebar, providing evidence of self-protection by development of a dense plasma near the bar [(Li-1), (Li-2), (Li-3)].1.5.3 REDUCTION OF THE SPUTTERING YIELD OF W BY IN-SITU NITRIDINGSeveral methods were used for the formation of a WN layer on W samples, includedplasma- assisted techniques in the MHEST association, Romania, like reactive sputtering andmagnetron sputtering with several degrees of mixing W/N interlayer mixing and thickness.However, SIMS analysis indicates that only a very thin (2nm) layer is produced by exposing Wsamples to a N/He GD. Also, N seeded discharges were performed in JET under the new ILWscenario, and some evidence of ammonia formation was seen through the de-convolution of themass spectra, with obvious implications in the particle balance analysis of D and N [JET PSI-12]. Samples from MHEST were exposed to Magnum PSI at DIFFER and a strong erosion,although compatible with at reported for the sputtering yield of WN 2 , was observed [WN-1]1.5.4 EDGE TRANSPORT AND PARTICLE AND IMPURITY SOURCE1.5.4.1 RADIAL PLASMA TRANSPORT AND RECYCLING OF NEUTRALS.The helium ratio technique applied with the "Double Imaging technique" (see point2.2.1.9) has permitted to obtain 2 dimensional images of electron temperature and density inTJ-II edge plasmas with temporal resolution of about 50 µs. Using the emission I from one ofthe recorded He I lines (667 nm), that is relatively insensitive to the electron temperature in thetypical operational range of TJ-II NBI heated plasmas (20 < T e < 100 eV) we can obtain in afirst approximation the neutral helium density distribution as n He I / n e . Comparison of the soobtainedradial n He profiles with EIRENE calculations are in good agreement. We apply thismethod to get the n He dynamic response low frequency edge modes and get a full dynamic 2dimensional picture of the plasma radial out-flux showing the T e , n e crash and the n Heinstantaneous wall-recycling response. The study is underway and will be concluded in 2013.1.6 PHYSICS OF PLASMA HEATING AND CURRENT DRIVE1.6.1 DEPENDENCE OF PLASMA FLUCTUATIONS ON RF STRAY RADIATIONA lot of work has been devoted to the improvement of the RF stray radiation detectionsystem. At present, all the stray radiation monitors ECA1, ECA2, ECA4, ECA5, which work inAsociación Euratom – CIEMAT .- Annual Report 2012 19

the continuous character of the AEs becomes altered and displays frequency chirping. If theECH power is further increased the AE can be eventually stabilised. This result suggests apossible tool for AE control that, if confirmed, could become ITER and reactor-relevant.Preliminary presentations were made at the ITPA Energetic Particles Topical Group meeting inLa Jolla, in October [20121015_ITPA_EP] and in the 22nd Toki Conference in November[20121119_ITC22].1.8 THEORY AND MODELLING FOR ITER AND DEMO1.8.1 PLASMA HEATING (NBI)The last versión of ISDEP (Integrator of Stochastic Differential Equations for Plasmas)code has been combined with to estimate the properties of fast ion collsional transport in ITER.First results on the fast ion distribution function and on slowing down times are available[bustos-thesis].1.8.2 COMPUTATIONAL DEVELOPMENTSGrid computingThe activities on grid computing and on the development of tools to improve theperformance of fusión code have been continued. We have implemented the technique of “PilotJobs” to improve the efficiency of DKES codeo n the grid [Rubio-IEEE-2012], obtaining a hugecapability for scanning the Neoclassical properties of several TJ-II configurations: running thecode using the Pilots under the metascheduler Gridway allows to launch a huge number of Jobsin a coordinated way.Workflow BuildingThe workflow FAFNER2-ISDEP has been built and applied to fast ion calculations. Thishappens to be sequential workflow, so no especial tool has been used for its implementation:The ISDEP code has been prepared to read the output of FAFNER, which hs been adpated toITER geometry. First results of fast ions transport were extracted [bustos-thesis].Moreover, Kepeler Workflow engine has been used to build heterogeneous workflowsamong codes that runo n different computing platfroms, as a proof of concept a combination ofthe codes VMEC, for equilibrium calculations, and DKES, which estimates the Neoclassicaltransport coefcients, is used [proc-ieee-2012-WFs].Asociación Euratom – CIEMAT .- Annual Report 2012 21

2 DEVELOPMENT OF PLASMA AUXILIARY SYSTEMS2.1 HEATING AND CURRENT DRIVE SYSTEMS2.1.1 ELECTRON BERNSTEIN WAVES HEATING EXPERIMENTS IN TJ-IIFull redesign of the matching optics unit (MOU): Discussions with GYCOM about thewaveguide coupling problem eventually led to the following conclusion: the beam distortioneffects, i.e. aberrations and production of higher order modes, generated by the large mirrorsize (due in turn to the large size of the MOU itself) prevented the proper coupling to the HE11mode at the waveguide mouth. A more compact design was undertaken in October 2012 inorder to minimize the beam distortion effects. The new design of the MOU makes it necessaryto move the gyrotron to a position closest to the waveguide. EBWH Experiments will beresumed during the first half of 2013.2.1.2 NBI HEATING STUDIES: ION TRAJECTORY CALCULATIONIon trajectory calculation: A realistic assessment of beam power losses due toreionization is necessary for the correct interpretation of the plasma-beam interaction.Reionization losses are particularly important in the beam duct connecting the beamline with thestellarator vacuum vessel. Ion trajectories must be evaluated, since the impact areas in the ductor vacuum chamber are a source of gas and impurities and must be protected from potentiallyhigh thermal loads.An ion trajectory code has been written (TRAYN) that follows the trajectories of ions inthe residual magnetic field of TJ-II from their birth point inside the NBI duct until they hit the wall,either in the duct or in TJ-II vessel. For the main ion energy (34 keV) and the magnetic fieldrange in the duct region (0.01 to 0.25 T), the center-guide approximation is not valid; therefore afinite Larmor radius approach has been implemented. A statistical approach has been followed,in that the ion birth points are uniformly distributed on perpendicular planes along the beamaxis. No assumption has been made on the distribution of birth points along the duct, since thisdistribution depends on the pressure profile which in turn depends on the gas re-emission areasinside the duct, where the hot spots due to ion striking points are located. The statistical resultspermit the ion birth region to be inferred from comparison with the observed hot spots on theinfrared images [Semin_Reion_TRAYN_120127].2.1.3 ECH ACTIVITIES IN TJ-II2.1.3.1 CHANGES IN THE GYROTRON RADIATION PROPERTIES, INDUCED BY A SMALLAMOUNT OF REFLECTED MODULATED POWER.The basis for these experiments is the hypothesis that a low fraction of the gyrotronemitted power, which is reflected back to its source, can strongly modify the gyrotron behaviourand produce a reaction on the output radiation depending on the phase of the reflected wave.Using a quasioptical divider, it has been demonstrated that the gyrotron radiation is indeedAsociación Euratom – CIEMAT .- Annual Report 2012 22

modulated by reaction to the reflected modulated power under controlled conditions and that thestrongest influence in seen in the beam periphery. Regular measurements with plasma werecarried out during the 2012 campaign and the results are still under analysis. This work hasbeen carried out in collaboration with the Institute of Applied Physics (Russian Academy ofScience), Moscow and Nizhny Novgorod (Russia).2.1.3.2 SECOND HARMONIC X MODE BREAKDOWN EXPERIMENTS.To complete the breakdown experiments carried out in previous campaigns theinfluence of the delay between the build-up of the plasma discharge and the flat-top of thecurrents in the device coils was investigated. The results of the experiments are summarized in[ECRH2].2.2 PLASMA DIAGNOSTICS2.2.1 DEVELOPMENT OF PLASMA DIAGNOSTICS IN TJ-II2.2.1.1. CALIBRATION OF THE MULTI-FOIL SOFT X-RAY DIAGNOSTIC (M4F) FOR COREELECTRON TEMPERATURE ESTIMATIONS.First-order approximation (i.e. by using fixed standard electron density and temperatureprofile shapes) of the central electron temperatures (Te0) estimated by the M4F diagnostic hasbeen benchmarked with the Thomson Scattering diagnostic. This has been done for plasmaswith different magnetic configurations, densities, NBI power inputs and plasma compositions.The agreement is very good in all cases except when the NB counter-injector was used. Thisdiscrepancy was attributed to the presence of metals in the plasma as a consequence of astrong interaction of this beam with the vacuum vessel. When iron was included in thecalculations, the agreement with Thomson was re-established. Second-order Te0 was alsoobtained by using the reconstructed SXR and total radiation emissivity profiles (SXR andbolometer tomography diagnostics) as a proxy to estimate the evolution of the electron densityand temperature profile shapes. This way, the temporal evolution of Te0 can now be reliablyobtained even for the case of strong plasma profile changes, as is the case of plasmas withtransitions from bell to dome profiles and/or L/H transitions [M4F].2.2.1.2 ION TEMPERATURE MEASUREMENTS BASED ON ATOMIC BEAMMEASUREMENTS AND RFA DIAGNOSTIC DEVELOPED BY IST.An upgraded RFA diagnostic system has been constructed by the IST Team during2012. It will be installed in the reciprocating probe drive, located at a high flux expansion regionto reduce the plasma heat flux to the diagnostic. Experiments are planned for the 2013 TJ-IIcampaign. Benchmarking with the atomic He-beamAsociación Euratom – CIEMAT .- Annual Report 2012 23

2.2.1.3 COMMISSIONING OF SECOND HIBP INJECTOR / ANALYZER FOR ZONAL FLOWSTUDIES IN TJ-II. (CAPITAL EXPENDITURE EXCLUDED UNLESS INCLUDED IN EFDA TASKAGREEMENTS)This project is the result of a big collaboration of Kharkov Institute, kurchatov instituteand Ciemat. The second line of heavy ion probe in TJII was installed and the whole system waschecked successfully including: new control and data acquisition system based on ITERcompatible PXI modules and Lab View software, Ciemat workshop built ion detectors, andCiemat electronics team produces preamplifiers, optocouplers, all of these components areinstalled and working. The actual bandwidth of the system is 500 kHz (3dB).The first test has been made and we obtain a current of 60 μA of Cs ions with a filamentcurrent of 12 A DC.We expect to find secondary ions before the end of June during the first 2013 TJIIexperimental campaign.The commissioning of the second HIBP will be held before the end of 2013.2.2.1.4 DEVELOPMENT OF A PELLET INJECTOR FOR TJ-IIThe construction of the compact 4-barrel pellet injector (PI) for the TJ-II was completedduring 2012 at Oak Ridge National Laboratory, Oak Ridge, Tennessee (where the mainhardware PI was built). In parallel, the preparation work for its installation continued at TJ-II.Laboratory testing of the system, i.e. production of pellets at 10 K and subsequent firing of thesolid pellets, was undertaken in March 2012 at ORNL [Combs1]. During testing, hydrogenpellets with diameters between 0.5 and 1 mm were created and fired. In addition, localdiagnostics for measuring the speed, mass and form of the pellets were demonstrated tooperate correctly. Once testing had been completed, the interface coupling required to attachthe PI to TJ-II, was designed and built at ORNL. Finally, the PI was packed and shipped toCiemat, where it was arrived in August 2012. Over the following months, the PI was installed onits support structure, designed and built at Ciemat, and the control electronics were installed inan electrical cabinet. In addition, systems such as gas manifolds, vacuum pumps, pressuretransducers and gas storage cylinders, were fitted to, and tested on, the PI. Finally, the cryorefrigerator,essential for achieving 10 K, was installed and checked. In March 2013, the PIsystem was cooled to 10 K for the first time at Ciemat. It is expected that the commissioning ofthe PI will be completed at Ciemat once the remote control system has been installed andtested. Once demonstrated, the first pellets can be created and injection of pellets in TJ-IIplasmas can begin.2.2.1.5. THE DIAGNOSTIC NEUTRAL BEAM INJECTOR AND ASSOCIATEDINSTRUMENTATIONStudies on TJ-II plasmas using the Charge Exchange RecombinationSpectroscopy technique continued during 2012. This diagnostic views the plasma minor radiusAsociación Euratom – CIEMAT .- Annual Report 2012 24

from 36 top, bottom and toroidal lines-of-sight. In particular these studies concentrated on fullyionizedcarbon ion flows in ECRH and NBI plasmas. In the first instance, it was demonstratedthat flow measurements, performed at different locations of the same flux surface, arecompatible with flow incompressibility for low-density plasmas (line averaged electron densities≤10 19 m -3 ). Furthermore, comparison with neoclassical calculations showed quantitativeagreement with measured radial electric field and ion parallel mass flow in the absence of anexternal momentum input. For the case of higher density plasmas, in surface variations of thisvelocity were observed systematically, thus pointing to a breakdown of impurity flowincompressibility at densities above 2x10 19 m -3 [Arevalo1].In order to maximize the scientific return of both the TJ-II diagnostic neutralbeam and its associated optics, studies were made using beam emission spectroscopy (BES)from a tangentially viewing port in sector B1. In a previous report, the viability of performing BESon TJ-II was demonstrated. For these studies, the DNBI neutral beam has been employedtogether with a 12-way fibre bundle, a narrowband filter centred on 659.6 nm, with a Full-Widthat Half-Maximum bandwidth of = 1 nm, and 6 avalanche photodiode modules, with highsensitivity (around 650 nm) and internal gain plus frequency response up to 1 MHz. The resultsof these studies, where localized modes were observed at specific radius of the TJ-II plasmawere reported at the XXIII Reunión Nacional de Espectroscopía VII Congreso Ibérico deEspectroscopía in Cordoba, 2012 [McCarthy1]. In addition, the results were present in a MasterThesis for the Joint European Master in Nuclear Fusion Science and Engineering Physics, atGhent University [Achkasov1].2.2.1.6 DOPPLER REFLECTOMETRY SYSTEMDesign and construction of a new Doppler reflectometerThe construction of the new Doppler reflectometer in the 50-75 GHz frequency band,done in collaboration with the IST Microwave Reflectometry Team, was finished during the firstpart of 2012, and its installation in TJ-II was implemented at the end of the first experimentalcampaign, in July. The system was tested and calibrated after the installation and startedoperation in the second experimental campaign in autumn. Band rejection filters have beendesigned and developed in collaboration with the Universidad Politécnica de Madrid to protectthe new system against the high power of the gyrotrons used to heat the plasma. They are thesubject of a publication in Fusion Engineering and Design [FED_Montejo_2012]. During 2012 anew approach to detect coherent modes using microwave reflectometry was developed. Theapproach is based on the modulation of the reflecting layer in the poloidal direction due to thepresence of rotating coherent MHD modes. The applicability of the approach wasdemonstrated, using either conventional or Doppler reflectometry, in plasmas with a highbackground turbulence level where the standard analysis method fails. These results, havebeen published in [NF_Estrada_2012]; it is worth mentioning that this article has been selectedby the Nuclear Fusion.Asociación Euratom – CIEMAT .- Annual Report 2012 25

2.2.1.7. STUDIES ON DOUBLE PULSE THOMSON SCATTERING MEASUREMENTSThe diagnostic has provided during 2012 in a regular way electron temperature (T e ) andelectron density profiles (n e ) for TJ-II discharge documentation & physics studies.The new Power Supply Unit (PSU), built by the laser company (INNOLAS, Rugby, UK)and delivered to CIEMAT in late 2010 has continued to be used intensively and with verysatisfactory results during the 2012 TJ-II plasma campaigns. The purchase of the new PowerSupply has been partially supported under Project ENE2009-10181, leaded by Dr. MaríaAntonia Ochando, CIEMAT. Following the successful proof-of-principle test of double pulseThomson Scattering shots made in the 2011 spring campaign, preliminary contacts with thelaser builder (INNOLAS UK) have been maintained so as to ask for the possibility of installing inthe laser a third amplifier, so as to raise its energy to the 20 J level (single pulse) or 10-10 J indouble pulse operation. This upgrade will increase diagnostic performance in particular whenmeasuring moderate-density ECRH heated plasmas. A quote has been received, estimating theupgrade in the order of € 75,000. More studies are needed in order to evaluate thecosts/benefits of the proposed upgrade.Software (SUN workstation) and Hardware (ruby laser) maintenance policies, whichhave been shown to be operative in previous years, have been continued during 2012. During2012 nevertheless, the main focus of the TS system has continued to be in providing T e and n eprofiles in single shot operation.The Thomson Scattering group in-kind collaboration (with Dr. R.F. Álvarez-Estrada,UCM, and Drs. J. Guasp and F. Castejón, CIEMAT) in theoretical/numerical relativisticThomson Scattering (ITER oriented) has continued during 2012, extending and generalizingpreviously obtained results so as to be able to compute in a purely analytical way the ThomsonScattering spectrum coming from nearly arbitrary electron distribution functions. In particular, asystematic exploration of the Thomson Scattering spectrum arising from non-Maxwellian oranisotropic electron distribution functions has been carried out and the results have beenpublished in [NF_Pastor_2012] and [PoP_Alvarez_Estrada_2012]. It is worth mentioning thatthe first article has been selected by the Nuclear Fusion Editors as part of the NF Highlights20122.2.1.8. NPA UPGRADINGDuring the 2012 year, the NPA top diagnostic was upgraded from 6 channels in H rowto 12 channels in H row. The operation included the manufacturing of some pieces in theworkshop, the assembly of the new detector’s row in the NPA and then the sending to IoffeInstitute in Saint Petersburg (Russia) for the calibration. Once calibrated was returned to thelaboratory were it was installed in its position and tested with the participation of two scientistsfrom Ioffe Institute.On the other hand, the DOUBLE code was adapted to work with TJ-II plasmas. It is acode developed in Ioffe Institute to simulate the flux arriving to the neutral particle analyzer. ThisAsociación Euratom – CIEMAT .- Annual Report 2012 26

code was adapted to the geometry and plasma parameters of TJ-II and the result of thesimulation agrees the experimental data [NPA1].The results of the code have been used to improve the calculation of the main iontemperature of the plasma, giving a correction of about 15% higher in both heating schemes,ECRH and NBI plasmas.2.2.1.9 TWO-DIMENSIONAL IMAGING OF EDGE PLASMA ELECTRON DENSITY ANDTEMPERATURE.A system was developed and validated in the past to image the electron temperatureand density at the plasma edge applying the helium line ratio technique with a fast camera. Themethod is being applied in TJ-II to analyze spatially coherent structures such as Edge Modesand Blobs. The time resolution is in the 10 ms range. Edge modes have a temporal quasicoherentcharacter in certain NBI heated regimes and begin with a flattening of the electrondensity profile near r/a = 0.75 and is followed by an outward heat pulse with a speed of typically100 m/s. On the other hand, the electron density of coherent turbulent structures (in thecentimetre range) called blobs and holes are up to +/- 1x10 18 m -3 corresponding to variations ofup to +/-100% of the mean value at the plasma last closed flux surface.2.2.1.10 INVESTIGATION OF NON-THERMAL ELECTRONS IN THE BOUNDARY REGION OFTHE TJII STELLARATOR FROM I-V LANGMUIR PROBE CHARACTERISTICSLangmuir probes are one of the most common diagnostic tools to measure edgeplasma parameters with sufficiently high temporal and spatial resolution. In non-magnetized,low density plasmas Langmuir probes allow local measurements of the plasma potential, thecharged particles density and the electron energy distribution functions (EEDF). In magnetizedplasma, the interpretation of current-voltage (I-V) characteristics is not straightforward above thefloating potential (i.e. the electron part of the IV characteristic is distorted due to the influence ofthe magnetic field). Using the electron branch of a Langmuir probe I-V characteristic it hasbeen shown the presence of a small fraction of supra-thermal electrons together with adominant Maxwellian distribution in ECRH plasmas whereas in high-density NBI regimes theelectron distribution function is Maxwellian.2.2.1.11. LINEAR ARRAY FOR ELECTRON TEMPERATURE MEASUREMENTS (M4FA)After more thorough simulations of the signals observed in the already mounteddiagnostic it was decided that, as the signal levels were high enough, it would be better todismount the diagnostic to install new narrower collimators to increase the spatial resolution. Atthe same time one of the channels was repaired and the in-vacuum amplifiers were substitutedby a new set of amplifiers, recently developed by the group of Electronics of CIEMAT. The newamplifiers have a better temporal resolution (up to 10µsec), lower intrinsic noise and much lowercross talk between adjacent channels. First light was obtained at the end of the last campaignAsociación Euratom – CIEMAT .- Annual Report 2012 27

and at the present time the analysis of the data in underway to produce the first electrontemperature profiles [M4FA].2.2.2 DIAGNOSTIC EXPLOITATION AND DEVELOPMENT IN JET2.2.2.1 COMMISSIONING AND MEASUREMENTS OF INTENSIFIED FAST VISIBLECAMERAS FOR PLASMA-WALL STUDIES IN JETAfter the successful installation of "test image intensifier" (on loan from CIEMAT) andthe extensive testing during the campaign JET decides that Image Intensifier will be helpful.Procurement of a new image intensifier (following the decision taken at the DSW+ Diagnosticspackage Project Board of 23.07.12). This procurement was made in 2012 and wecommissioned the new Image Intensifier at Ciemat in December 2012. In December 2012 westart the absolute calibration of the system at JET, and in the next months we plan to obtainquantitative data from the fast camera images, this calibration will be finalized in 2013.We are starting to work in the correction of the rotation of the image due to thecombination of magnetic fields and first stage of amplification of the Image Intensifier, followingtwo different approximations, in collaboration with MeDC Association. For this topic, Ciematstarts to develop a procedure to realize the software correction of the translational and/orrotational movements experimented by the KL8A images using an automatic registrationalgorithm with corresponding point position prediction. Assuming a rigid rotation/displacementmodel, a transformation matrix, which determines how the input image must be transformed inorder to be aligned with the base image, is computed. First results were promising.The project FC7-2phase is planned to be handed over and closed at the end ofSeptember 2013 when the Final Report is approved.2.2.3 DEVELOPMENT OF PLASMA DIAGNOSTICS IN W7X: IRINTERFEROMETRY2.2.3.1 DEVELOPMENT OF A MODULAR SYSTEM OF CO 2 INTERFEROMETERDIAGNOSTICSeveral basic works have been done. As it has been reported previously, the two-colourinterferometer of TJ-II has been operating using CO 2 laser (10.591 µm wavelength) and NdYAG(1.064 µm), instead of the previously used He-Ne (0.633 µm), because the ZnSe windowsthermo-optical dispersive effect is about 10 times lower for the NdYAG wavelength. It wasknown that the arms of an interferometer using He-Ne lasers can be unequal; fact that permits asubstantial engineering simplification in the modular design because many mirror componentscan be eliminated. Now, we have proved experimentally that also when using a NdYAG laserthe interferometer can have very different arm lengths (almost 10 meters). This is interestingbecause the laser type, Solid State Diode Pumped laser is very different to the He-Ne. Theactual stabilized laser has enough coherence length to permit this asymmetry, maintaining theAsociación Euratom – CIEMAT .- Annual Report 2012 28

previous noise level. The asymmetric modular system is smaller and simpler than the symmetricone and the alignment procedure is notably easier.Also, the thermal stability in lasers with controlled temperature has been studied fordifferent water chillers.Finally, the new phase-meter based in FPGA has been implemented and tried2.2.4 DIAGNOSTIC DEVELOPMENT IN ITER2.2.4.1 REFLECTOMETRYThe extrapolation of present day microwave reflectometry systems to future devices likeITER is possible but, in order to achieve a good diagnostic performance, special care must betaken in the diagnostic front-end design and construction. The main limitations related torelativistic effects, intense neutron- and γ-radiation and long pulse or steady-state operationhave been reviewed and published as an Overview Article in [PFR_Estrada_2012].In 2012, the consortium comprised of CIEMAT, IST and IFP-CNR was selected for theaward of the Framework Partnership Agreement for Diagnostic Development and Design, F4E-FPA-375 (DG): Plasma Position Reflectometer. As specified in the FPA-375 Proposalelaborated by the Consortium to apply to the F4E-FPA call, the FPA concerns the supply ofR&D and design related to the ITER Plasma Position Reflectometer and consist of a number ofSpecific Grants between F4E and the Consortium partners. In particular CIEMAT will have fullresponsibility of three of these Grants and will participate in another two, the first one dealingwith the Detailed Planning of the whole project and therefore of the subsequent Grants and thesecond one being the Coordination Office.2.2.4.2 VISIBLE – IR WIDE ANGLE VIEWING SYSTEM:CONSORTIUM CEA / CIEMAT /ENEA / HAS / ISTThe Consortium comprised of Commissariat à l'énergie atomique et aux énergiesalternatives (CEA) and Centro de lnvestigaciones Energéticas, Medioambientales yTecnológicas (CIEMAT) has been selected for the award of the Framework PartnershipAgreement for Diagnostic Development and Design of Equatorial Visible/lnfrared Wide AngleViewing System for ITER.2.2.4.3 THOMSON SCATTERINGKeep-in-touch activities of the Thomson Scattering Group in TJ-II with the Consortiumto build the Thomson Scattering system for ITER have been maintained during 2012. The scopeof possible Thomson Scattering designs for ITER has been widened from the previous (LIDAR)design, due to the challenges posed by a LIDAR system to the existing laser and/or detectortechnology. CIEMAT’s contribution will continue to be focused on the theoretical/numericalaspects of the relativistic laser/electron interaction relevant for Thomson Scattering in very highAsociación Euratom – CIEMAT .- Annual Report 2012 29

temperature plasmas, and on calibration techniques suitable for the final design adopted by theConsortium partners.2.2.5 REFLECTOMETRY SIMULATIONS2.2.5.1 REFLECTOMETRY SIMULATIONS: DEVELOPMENT OF A 3D FULL-WAVE CODERELEVANT FOR ITER.A three dimensional (3D) simplified kernel was developed during 2010 and 2011 by theReflectometry Code Consortium. The kernel has the essential algorithm’s difficulties found in acomplete 3D modelling but absorbing boundary conditions, launching and receiving antenna,plasma turbulence, etc. were intentionally omitted. During the 2012 most of the work has beenfocussed in the implementation of the launching/receiving module and in the implementation ofthe absorbing boundary conditions. These two upgrades have been integrated into the spatialparallel scheme of the simplified 3D kernel with partial success. In particular, we have testedthe power injection module and some bugs were found in the code. It was found that theemitted power was not completely uni-directional resulting in some microwave power of about -20 dB being reflected back from the emitting plane. The source of this error still requires moretime and tests to be fully identified. It seems to be related to the external applied field to thecomputational grid and its phase all along the emitting plane. In addition, the absorbingboundary conditions (PML) were found to be working properly with some minor problems in thecorners of the computational domain. The effect in the received microwave power wasestimated to be not very important and the correction of this bug was delayed for a later revisionof the code.Results:a. Signal injection and detection modules have been implemented into the presentkernel version. More work is needed to remove some minor bugs found in the code.b. Absorbing boundary conditions have been implemented.c. Test of the new version of the code started in 2012.Outstanding issues:d. Improve antenna-vacuum-plasma propagation time by means of Green's functions orequivalent algorithms.e. Introduce plasma turbulence with high turbulence levels to test code stability in 3D.f. Improve computational time by means of optimum communication and data transferbetween processors.2.2.6 ADVANCED DATA ANALYSIS TECHNIQUESThis section includes different subsections related to the research on advanced dataanalysis techniques on several topics: disruption prediction (except the activities related to theAsociación Euratom – CIEMAT .- Annual Report 2012 30

JET real-time prediction that are included in section 2.4.2), L/H transitions, image processingand miscellanea.2.2.6.1 DISRUPTION PREDICTIONAs it was mentioned above, this part does not include the works about disruptionpredictions carried out on the JET real-time data network. However, with regard to JET, it isimportant to point out a research article concerning automatic feature selection for disruptionpredictors based on genetic algorithms [ADA_1]. Following with JET predictions, a postercontribution was presented at the 27 th SOFT Symposium (September 2012) whose novelty isthe proposal of an automated classification system that relies on the probability distribution offrequencies in several indicator signals in the wavelet domain. The system discriminatesbetween disruptive and non-disruptive plasma behaviour by measuring the geodesic distancebetween the wavelet distributions on the corresponding probabilistic manifold [ADA_2].Also related to JET disruptions, a new prediction method was proposed in the 7 thWorkshop on Fusion Data Processing Validation and Analysis (March 2012). A particularclassification methodology was discussed by using wavelet statistical features in conjunctionwith geodesic distances on a manifold [ADA_3]. The work was applied not only to disruptionprediction but also to confinement regime identification [ADA_4] with the ITPA Global H-modeConfinement Database.2.2.6.2 CONFINEMENT TRANSITIONSDuring 2012, this topic has been investigated with several databases and differenttechniques. In addition to the results obtained with the ITPA Global H-mode ConfinementDatabase presented in section 2.2.6.1 [ADA_3] and [ADA_4], a technique based on conformalpredictors [ADA_5] was presented at the International Conference “Artificial IntelligenceApplications and Innovations” (September 2012). The measurements are modelled byprobability distributions in a metric space. The conformal predictor framework providesconfidence and credibility measures for the interpretation of results [ADA_6].Automatic location of L/H transition time instants have been carried out for JET. Thedifference of this work with previous ones resides in the estimation of a probability confidenceinterval of the prediction [ADA_7]. Together with this analysis concerning the L/H transition, anarticle related to the H/L transition in JET was published [ADA_8]. The estimated transitiontimes are qualified with measures (confidence and credibility) about how reliable the predictionsare.The technique developed in JET [ADA_7] for the automatic recognition of L/Htransitions has been applied to the database of the DIII-D tokamak and the results werepublished in [ADA_9].Asociación Euratom – CIEMAT .- Annual Report 2012 31

Derivation of a scaling law for the H-mode power threshold using the ITPA Global H-mode Confinement Database [ADA_10] was presented at the 7 th Workshop on Fusion DataProcessing Validation and Analysis (March 2012).Research not directly related to the confinement transition but related to the H-modehas also been developed. In particular, results about the analysis of pedestal confinementdegradation, induced by ELMs in JET [ADA_11] were presented at the 7 th Workshop on FusionData Processing Validation and Analysis (March 2012). An important aspect of the investigationis the automatic location of ELMs. This automatic method has allowed the analysis of 748 JETdischarges and 46187 ELMs [ADA_12].2.2.6.3 IMAGE PROCESSINGAdvanced image processing methods have been an important activity during 2012. Twodifferent compilations of present techniques were respectively presented at the 7 th Workshop onFusion Data Processing Validation and Analysis (March 2012) [ADA_13] and published in[ADA_14]. State of the art techniques were developed and applied according to the followingtable:Work Conference ArticleRecognition of the mostimportant regions to develop imageclassifiersADA_15Development of active learningtechniques for image classification byusing conformal predictors7th Workshop onFusion Data ProcessingValidation and Analysis(March 2012): ADA_16ADA_17Noise reduction in the TJ-IIThomson Scattering images7th Workshop onFusion Data ProcessingValidation and Analysis(March 2012): ADA_18ADA_19Image de-noising 10th InternationalFLINS Conference: ADA_20Image classification usingphase congruencyADA_21Improved techniques for fastimage recognition in the conformal27thSymposiumSOFT(SeptemberAsociación Euratom – CIEMAT .- Annual Report 2012 32

predictor framework2012): ADA_222.2.6.4 OTHER WORKSThis subsection includes a miscellanea of works on advanced data analysis techniquesnot related with anyone of the above subsections.To start, it should be mentioned a publication of an overview about statistically hedgedprediction methods [ADA_23].In the 7 th Workshop on Fusion Data Processing Validation and Analysis (March 2012),an invited talk about data-driven models was given [ADA_24]. In the same Conference, twoother contributions were presented. On the one hand, a work on model selection criteria[ADA_25] was described. On the other hand, the integration of GPU technologies for real-timedata analysis was discussed [ADA_26].A novelty research on conformal predictors based on fuzzy logic classifiers [ADA_27]was presented at the International Conference “Artificial Intelligence Applications andInnovations” (September 2012) and it also has been published [ADA_28]. Last but not least,new classes of indicators for the selection of scaling laws in fusion were presented inSeptember 2012 at the 27 th SOFT Symposium [ADA_29].2.3 REAL TIME MEASUREMENT AND CONTROL2.3.1. ADVANCED DATA ACQUISITION SYSTEMSThis section is devoted to explaining the work carried out on two ITER Fast PlantSystem Controller prototypes during 2012. Two form factor prototypes were tested: PXIe andATCA. A general description about the prototype based on the PXIe form factor can be found in[ADAQ_1]. The equivalent development on ATCA is [ADAQ_2]. CIEMAT has been mostinvolved in the PXIe form factor and several contributions to Conferences and articles detailspecific parts of the PXIe prototype. A first work to be mentioned is the oral presentation in the7 th Workshop on Fusion Data Processing Validation and Analysis (March 2012) on the dataacquisition and pre-processing implementation of FPGA-based cards [ADAQ_3]. Taking intoaccount the large processing capabilities of the data acquisition systems in ITER, the integrationof GPUs in the PXIe prototype was tested in [ADAQ_4]. Due to the fact of the high demandingarchiving requirements, a particular solution based on NetCDF was analysed in [ADAQ_5].Finally, the integration of the FlexRIO technology and EPICS was discussed in a contribution[ADAQ_6] to the 18th Real-Time Conference (June 2012).2.3.2 REAL-TIME DISRUPTION PREDICTORSThe impact of disruptions in JET became even more important with the replacement ofthe previous Carbon Fiber Composite (CFC) wall with a more fragile full metal ITER-like wall(ILW). The development of robust disruption mitigation systems is crucial for JET (and also forAsociación Euratom – CIEMAT .- Annual Report 2012 33

ITER). However, a reliable real-time (RT) disruption predictor is a pre-requisite to any mitigationmethod. The Advanced Predictor Of DISruptions (APODIS) has been installed in JET for the RTrecognition of disruptions. The predictor operates with the new ILW but it has been trained onlywith discharges belonging to campaigns with the CFC wall. Three aspects must be emphasized.Firstly, the predictor follows the design of a previous APODIS version (combination of supportvector machines (SVM) classifiers) but it differs in several aspects such as (a) the amount oftraining shots (10845 shots of campaigns C15-C27); (b) an exhaustive data pre-processing toremove discharges with outlier signals; (c) the use of high performance computing for trainingpurposes. Secondly, the predictor has been integrated (open loop) in the JET Real-Time DataNetwork (RTDN) using the MARTe RT framework. Thirdly, a multi-objective problem has beentackled in the predictor: high success rate and low rate of false alarms. Seven real-time signals,which are characterized every 32 ms through their mean value and energy distribution amongfrequency components, are used to identify the plasma status (disruptive or non-disruptive).A simulator of the APODIS real-time implementation was presented [RTDP_1] at the 7 thWorkshop on Fusion Data Processing Validation and Analysis (March 2012). The full real-timeimplementation in the JET RTDN [RTDP_2] was presented in the 18th Real-Time Conference(June 2012). The APODIS disruption predictor was also presented in this Conference as part ofthe new generation of real-time systems in JET [RTDP_3].First results about the prediction capabilities of APODIS [RTDP_4] were discussed inthe 22 nd ITPA Diagnostics Topical Group Meeting (May 2012). During 2012, APODIS resultswere discussed in JET working groups [RTDP_5] and JET Task Forces Meetings [RTDP_6].The global evaluation of APODIS during the first three ILW campaigns [RTDP_7] was presentedin an oral contribution at the 27 th SOFT Symposium (September 2012). During thesecampaigns, 991 discharges were produced. The predictor success rate is 98.36% (alarms aretriggered in average 426 ms before the disruptions). The false alarm and missed alarm ratesare 0.92% and 1.64% respectively. The APODIS capabilities outperform the ones provided bythe JET standard mode lock trigger system.Asociación Euratom – CIEMAT .- Annual Report 2012 34

3 DEVELOPMENT OF CONCEPT IMPROVEMENTS ANDADVANCES IN FUNDAMENTAL UNDERSTANDING OF FUSIONPLASMAS3.1.2 IMPURITY TRANSPORT3.1.2.1. IMPURITY CONFINEMENT.The simultaneous achievement of high energy and low impurity confinement times iscrucial for obtaining relevant nuclear fusion plasmas. One of the critical issues for stellarators isthe avoidance of impurity accumulation. Laser blow-off injection of boron carbide, iron andlithium fluoride films has been used to perform trace seeding of different impurities into the coreof ECR-heated plasmas in the TJ-II stellarator. We have studied the dependence of globalimpurity confinement time with impurity injection velocity; with the injected impurity and itscharge state; and the isotopic effect, when the TJ-II is operated with deuterium. [SPEC_3].3.1.2 EXPERIMENTAL INVESTIGATION OF PROFILES STRUCTURES ANDPLASMA INSTABILITIES3.1.2.1 DYNAMICAL COUPLING BETWEEN GRADIENTS AND TRANSPORT.Understanding the relation between free energy sources and transport is a fundamentalissue in systems far from thermal equilibrium that has been debated for years. A non-linearrelation between heat fluxes and driving gradients can explain the confinement degradation withincreasing heating power that has been reported in all magnetically confined fusion plasmas.The transition to improved regimes also suggests a non-monotonic relation between gradientsand fluxes at a given specific radial position where the transport barrier is located. In parallel, itis well known that edge turbulent transport is strongly bursty and that a significant part is causedby few large transport events within a small fraction of time; this universal observation andstriking similarity between the statistical properties of edge turbulent transport in magneticconfinement devices is possibly reflecting the fact that systems out of thermal equilibrium aredynamically exploring different accessible states, i.e. regimes with different plasma gradientswith corresponding different transport levels.The dynamical coupling between density gradients and particle transport has beeninvestigated and compared using similar experimental tools in the plasma boundary of differenttokamak (JET, ISTTOK) and stellarator (TJ-II) devices [Hidalgo2012]. It has been observed thatthe size of turbulent events is minimum in the proximity of the most probable density gradient.Experimental results were found to be consistent with results from two very different models ofplasma turbulence and transport. The present findings, common to several plasma devices,suggest the importance of self-regulation mechanisms between plasma transport and gradientsin fusion devices.Asociación Euratom – CIEMAT .- Annual Report 2012 35

CONCEPTS3.2 UNDERSTANDING OF PLASMA CHARACTERISTICS FOR IMPROVED3.2.1 DESIGN OF AN OPTIMISED STELLARATOR USING GENETICALGORITHMS AND GRID COMPUTINGWe have continued the development of DAB (Distributed Asynchronous Bees) code foroptimization of stellarators based on Metaheutistics [Gomez-CI-2012] and we have added morecriteria (NC transport and stability). This algorithm has been adapted to be used in generaloptimization problems, showing its flexibility. The algorithm has been tested in TJ-II showing thelimited capability of optimization of this device without strong changes in the hardware of themachine. An optimised three-period heliac has been also obtained and its properties have beenstudied [Castejon-SW-2012]. In particular, the evolution of rotational transform profile with theplasma pressure and the values of the effective ripple have been studied [Castejon-ppcf-2013].3.2.2 RETENTION AND RECYCLING OF H/D IN SOLID AND LIQUID LITHIUMThe exchange between H/D isotopes on Li films was investigated. Mass spectrometricrecordings of H 2 release in D plasmas agree with high-resolution emission spectra of Da andHa lines. Preferential release of the opposite isotope in the form of HD was found. Two differentlevels of isotope exchange were found depending on plasma region, being much smaller at thecentre of the plasma. Exposure of the LLL to the plasma at RT, 200 and 400 ºC yieldeddifferent uptake of H. A TDS peak at 375 ºC was seen for exposures at RT and 200 ºC, while norelease at all was seen at 400ºC exposure. The desorbed amounts were compatible with totaluptake of the fuelled gas, given the small limiting effect of the LLL, and implies concentrations of

magnetically resonant regions as transport controllers has been suggested and found alsocompatible with much of the phenomenology of TJ-II plasmas studied to date [paperEX-P4-18].3.3 OTHER EXPERIMENTAL STUDIES3.3.1 NON-THERMAL ION STUDIES3.3.1.1. FAST ION SLOWING DOWN TIME MEASUREMENTSThe dynamics of fast ions injected in the plasma was studied using the compact neutralparticle analyzer (CNPA). In a ECRH plasma a small amount of fast ions was injected. Thechannels of CNPA follow the fast ions at different energies. When the fast ion injects ends thetime each CNPA takes to go to 0 is measured. From this time the slowing down time of ions atdifferent energies is deduced [NPA2].3.3.1.2. SUPRATHERMAL IONS IN TJ-II PLASMAS.We studied the empirical behavior of suprathermal ions in the ECRH and NBI phases ofthe TJ-II stellarator [SPEC_1]. We combined passive emission spectroscopy, which detectsconfined suprathermal ions with energies up to hundreds eV, and a luminescent probe operatedas a multichannel fast-ion energy spectrometer using pulse height analysis, which detectssuprathermal ions with energies ≥ 1 keV that escape from the plasma. We took data fromdensity and power scans of TJ-II ECRH plasmas and the spatial and time response ofsuprathermal protons and impurities in both scenarios. The comparative behavior between thesuprathermal ions present in the plasma and those escaping ions, may shed some light on thephysical mechanisms responsible for the generation and confinement of these ions.3.3.2 DUST STUDIES3.3.2.1 DUST STUDIES IN TJ-II.Dust is observed in the TJ-II stellarator with a fast camera equipped with a bifurcatedcoherent fibre-bundle system that allows different set-ups such as dual filtering of atomic linesor a stereoscopic view to obtain tangential and perpendicular (to the magnetic field)observations simultaneously. The camera looks to a poloidal limiter that can be biased and it isobserved that when a negative voltage is applied, dust from the limiter is ejected intensely oncea certain threshold voltage is exceeded. From the analysis of the simultaneous observation ofthe filtered and unfiltered images, we conclude that most of the unfiltered visible dust is outsidethe confined plasma, in the far scrape-off layer [DUST]. This work was a continuation in 2012 ofthe EFDA task WP11-PWI-0207-01. The experiments were partly performed in collaborationwith the National Institute of Fusion Science (Japan).3.3.3 MHD STUDIES3.3.3.1. MHD ACTIVITY AND RADIAL TRANSPORT BARRIERS IN TJ-II PLASMASAsociación Euratom – CIEMAT .- Annual Report 2012 37

Experimental studies of MHD related transport phenomena have been carried out inNBI-heated plasmas with different magnetic configurations. Analyses of locally resolved plasmaemissivity site the inversion point of radial transport events, such as off-axis sawteeth and elmslike,close to the predicted position of rational values in the rotational transform profile. Also,formation of barriers, both at the core and at the periphery, seems to be tightly linked to thelocation of resonant layers. Magnetic diagnostics signals spectra show coherent MHDperturbations in concert with the observed in radiation signals. A brief review of the observationswas presented in the 24 th IAEA Fusion Energy Conference, in October 2012 [RAD-MHD_2].3.3.3.2 PLASMA CURRENT DEPENDENCE OF COHERENT MODES FREQUENCY IN LOW-DENSITY NBI HEATED PLASMAS.Coherent MHD modes with intermediate frequencies f, 50 ≤ f ≤ 200 kHz, excited by fastions do not present the typical alfvenic dependence either on density or on plasma temperature.In contrast, their frequency exhibits a tight correlation with the net plasma current evolution.Also, under stationary plasma current conditions, modes frequency (and in all probability,position) noticeably and rapidly shifts when transient radial transport events occur [RAD-MHD_1]. The link with rational surfaces and the ohmic modulation of the filamentary currentintensity associated to them is under investigation.3.4 THEORY AND MODELLING3.4.1 NEOCLASSICAL STUDIESNeoclassical transport and ambipolar radial electric field in stellarators.The long-wave lenght radial electric field in non-quasisymmetric stellarators isdetermined by Neoclassical Theory. As a summary of a previous work, we report the parameterand configuration dependence of the neoclassical electric field for TJ-II plasmas [velasco1]. Wethen compare the theoretical predictions with experimental measurements for high densityplasmas of TJ-II [velasco2] in the framework of an international collaboration. The time evolutionof the radial electric field for slowly-varying time-dependent profiles is calculated in[velasco3],[velasco4],[velasco5],[velasco6],[velasco7], in which the so-called low densitytransition is described from first principles. We also show that the deviations of the radial electricfield from ambipolarity can be described by means of a viscosity coefficient which vanishes atthe transition. This vanishing allows to understand, in the framework of neoclassical theory, awealth of previous experimental results, including the observation of long-range-correlated lowfrequencypotential fluctuations close before the transition.3.4.2 GYROKINETIC EQUATION DEVELOPMENTSFoundations of Gyrokinetic TheoryProof of the intrinsic ambipolarity of the turbulent tokamak.Asociación Euratom – CIEMAT .- Annual Report 2012 38

In collaboration with Félix I. Parra (MIT, USA), the long-wavelength limit of thegyrokinetic equations in tokamak geometry has been computed to second order in theexpansion parameter, the Larmor radius normalized by the macroscopic scale length[CalvoParra_PPCF_2012]. This allowed to us to prove that the turbulent tokamak is intrinsicallyambipolar. It implies, in particular, that the calculation to second order accuracy is needed inorder to determine the tokamak long-wavelength radial electric field and, equivalently, radialtransport of toroidal angular momentum and intrinsic rotation. That is why we have given explicitexpressions that could be implemented in a computer code.Review on tokamak intrinsic rotation.In the last years there has been remarkable progress in the understanding of theproblem of predicting tokamak intrinsic rotation within the framework of gyrokinetics. The topic istechnically difficult and subtle, and a brief survey has been written (in collaboration with Félix I.Parra, Michael Barnes and Peter J. Catto, MIT, USA) that will help interested researchers to geta suitable perspective [Parra_PoP_2012].3.4.3 EUTERPE CODE DEVELOPMENTThe simulation of linear relaxation of zonal flows in stellarator geometry with thegyrokinetic code EUTERPE has continued. The zonal potential perturbations showed a fastdecaying GAM type oscillation and also a low frequency oscillation, in qualitative agreementwith expectations derived from previous theoretical calculations.The influence of the magnetic configuration, temperature, long wavelength radialelectric field and the radial scale of the initial perturbation on zonal flow oscillations has beenstudied by means of electrostatic simulations with adiabatic electrons in the three-dimensionalgeometry of TJ-II [ESanchezPPCF2013], [ESanchez_TJIIRH_GKT_Jun21]. No influence of themagnetic shear on zonal flow oscillations has been found so far.Detailed simulations have been carried out in ECRH typical TJ-II plasmas in order tostudy the possible relation between long range correlations observed in potential measurementsaround the low density transition in TJ-II and the linear relaxation of zonal flows.The code CAS3D-K, developed in the Max Planck IPP Greifswald, has been applied tothe TJ-II geometry in order to semi-analytically estimate an approximated linear response tozonal potential perturbations and compare it with gyrokinetic simulations. The first resultsshowed qualitative agreement between CAS3D-K semi-analytical calculations and EUTERPEsimulations [MasterThesis_PedroMonreal], however more detailed semi-analytical calculationsare needed for a deeper quantitative understanding of the underlying physics. Work is inprogress.Software tools for the visualization (in images and video) of three dimensionalinformation obtained from gyrokinetic simulations [http://fusionsites.ciemat.es/kinetictransport/]have been developed.Asociación Euratom – CIEMAT .- Annual Report 2012 39

Some work has been done on the characterization of linear micro-instabilities in TJ-IIplasmas. Density and temperature profiles typical from different plasma scenarios have beenreconstructed and preliminary linear simulations of ITG/TEM instabilities have been carried outin these conditions. The work in this line is ongoing.3.4.4 MHD STUDIESMagnetic phase transitions in plasmas and transport barriersA model of magnetic phase transitions in plasmas has been developed: plasmaelements with pressure excess or defect are dia- or paramagnets and move radially under theinfluence of the background plasma magnetization. It is found that magnetic phase separationcould be the underlying mechanism of L to H transitions and drive transport barrier formation.Magnetic phase separation and the associated pedestal build-up, as described here, can beexplained by the well-known interchange mechanism, now reinterpreted as a magnetizationinterchange. The interchange mechanism can drive motion of plasma elements even whenstable. A testable necessary criterion for the L to H transition has also been developed[SolanoMHD_NF52]. See also [EPS_2012_Oral]3.4.4.1 MHD PROPERTIES OF H-MODE TRANSITIONLow-frequency MHD mode activity was studied at the TJ-II stellarator. Several MHDmodes could be identified in discharges with a spontaneous confinement transition in differentbut similar magnetic configurations. The poloidal mode rotation profile could be reconstructedand was found to be consistent with earlier work. The detected mode spectrum also provided anexplanation for the bicoherence observed in one of the configurations after the confinementtransition. Both the mode spectrum and the velocity profile were closely reproduced bynonlinear resistive MHD calculations in simplified geometry. As a consequence, the magneticReynolds stress was hypothesized to play an important role in the establishment of the velocityshear layer in TJ-II and the concomitant confinement transition [NF2012_Milligen]3.4.5 TRANSPORT AND TURBULENCE BASIC RESEARCHNon-local transport and barrier dynamics.Several LNF works on models that reproduce the experimental facts of “non local”transport and pulse propagation in magnetically confined fusion plasmas have been compiledand reviewed [Ciematito1269]. They are based on fluid transport models, originally designed toexplain the formation of edge or internal transport barriers, which include fast evolutionequations for the particle and heat fluxes. The heating of the plasma core in response to asudden edge cooling or the propagation of turbulent fronts around transport barriers are aconsequence of the competing roles of linear drive and non-linear reduction of the turbulentfluxes. These models can be used to interpret the behaviour of TJ-II plasmas as well.3.4.5.1 MATHEMATICAL RESULTS ON NON-GAUSSIAN PROCESSESAsociación Euratom – CIEMAT .- Annual Report 2012 40

Extreme Value Theory and Renormalization Group.As a continuation of previous work on a Renormalization Group (RG) approach to Lévydistributions, we have dealt (in collaboration with Fernando Falceto, J. G. Esteve and Juan C.Cuchí, University of Zaragoza, Spain), in the same spirit, with the fundamental problem ofExtreme Value Theoy: finding the possible limit distributions of suitably rescaled maxima ofsequences of independent, identically distributed random variables. These problems, connectedto non-gaussian statistical phenomena, could be important for modeling of transport in certainfusion plasma regimes. Employing the techniques of RG, a family of limit distributions that onlyrecently appeared in the literature is obtained in a natural fashion [Calvo_PhysRevE_2012].3.4.5.2 UNCORRELATED LORENTZIAN PULSES AND EDGE TURBULENCERecently, it was proposed (by other authors) that the turbulent fluctuations measured ina linear plasma device could be described as a superposition of uncorrelated Lorentzian pulseswith a narrow distribution of durations, which would provide an explanation for the reportedquasi-exponential power spectra. We have studied the applicability of this proposal to edgefluctuations in toroidal magnetic confinement fusion plasmas. For the purpose of this analysis,we introduced a novel wavelet-based pulse-detection technique. When applying the wavelettechnique to edge turbulent fluctuation data from the W7-AS stellarator and the JET tokamak,we found that the pulses detected in the data do not have a narrow distribution of durations andare not uncorrelated. Instead, the distributions are of the power-law type, exhibiting temporalcorrelations over scales much longer than the typical pulse duration. These results suggest thatturbulence in open and closed field line systems may be distinct, and cast doubt on thementioned proposal [PRL2012_Milligen]3.5 TJ-II ENGINEERING AND OPERATION3.5.1 ENGINEERING ACTIVITIESThe TJ-II engineering group develops its activities in the following projects and/oractivities: TJ-II, design and construction of the cryostat for JT-60SA and design ofcomponents/systems for ITER. In this section only the first item (TJ-II activities) is covered. Theother two are reported in section 6.5.2 and 6.6.3.3.5.1.1 ACTIVITIES IN THE TJ-II EXPERIMENTThe activities carried out in the TJ-II are divided into three areas: the technical operationof the device during the plasma experiments, the maintenance and upgrading of systems andcomponents, and the installation of new equipment.3.5.1.1.1 TECHNICAL OPERATION OF TJ-IITwo engineers carry out the operation of the TJ-II. An engineer is in charge of theexperiment and another one is in charge of a large pulse generator and the power supplies forAsociación Euratom – CIEMAT .- Annual Report 2012 41

the experiment coils. The engineers have the responsibility of the safety systems and safetyprocedures fulfilment.3.5.1.1.2 MAINTENANCE AND UPGRADING OF SYSTEMS AND COMPONENTSControl SystemThe activities in relation to the TJ-II Control System during the year 2012 have beenconcentrated in the conclusion of the system upgrade, which began in 2008. Additionally anumber of new functions and improvements have been set forth in the Fast Control subsystem,based on the experience during the daily work, in order to facilitate the operation of theexperiment. These main works during the year 2012 are hereafter described.The maintenance of the system has been carried out regularly: periodic checks weremade and some preventive maintenance tasks were conducted through, as e.g. calibration andtest of the whole Control System channels, and repairing damage channels.15 kV cables in rectifier transformers. The regular inspection of the electricalinstallations, made every two years by a qualified company, has shown defects in theconnection cables to the 15 kV off-site transformers (small bending radius, deformations ofterminals) due to cold-warm cycles. Additional frames have been located for better cablesupporting.Electrical Systema) Insulation sleeves supporting the brushes arrangement in the DC pony motorRegular inspections of the insulation resistance to ground of the motor-generator setare shown from time to time low values in the motor rotating windings (27 MΩ at 500V test).After a visual inspection it was detected a damaged insulation sleeve: some cracks in theinsulation material. The element was substituted and the insulation level recovered.b) Temperature sensor Pt-100 in the generator bearingsA Pt-100 sensor located in one of the bearings of the pulse generator was substitutedbecause of its functional characteristics were lost. The sensor has an important role in thesurveillance of the lubrication system.c) Electrical protection of the pulse generatorPulse generator has the electrical protections set duplicated for safety reasons. One ofthe protection relays MCX 913 had a fault and it was necessary to repair it at the manufacturerbecause of the special characteristics (it has to operate in a variable frequency network 80÷100Hz) and calibration process to came back the component to its standard performance.d) Cooling tower of the water cooling systemDuring the operation of TJ-II a ground fault was detected by the electrical protection inthe distribution board of the auxiliary systems of the motor-generator set. After to test theAsociación Euratom – CIEMAT .- Annual Report 2012 42

different element it was a leakage current was found in the motor of the fan of the cooling tower:the terminal box was hardly damaged by the water and its salts dissolved. The contaminationhad also damaged the windings of the motor and a new unit had to be installed because of thecost of the repairs.e) Generator excitation systemThe excitation system of the pulse generator has to manage a high magnetic energyand in the case of a fault in the generator output has to remove that energy as fast as possible.To operate in this way a crowbar circuit is within the system: a misoperation was detected in thecrowbar because of a damaged small power supply in the control circuit. The new power supplywas installed.f) Conditioning of the cables gallery between electrical building and TJ-II building.A hard cleaning and repairs of safety services of the gallery have been carried outduring the summer shutdown.g) Upgrade of the control system power supply.The control system of the power supply of TJ-II has a central server type HP 9000-E35and two CPU´s HP 743 RT. The problems that from time to time appear during the start-up andthe lack of spare parts in the market, even at the original supplier HP, have been considered tolook for a similar spare unit which is now ready offline. The company presently in charge of themaintenance of the system has installed an equipment HP 9000-E45 with better performancesthan the in-operation one but fully compatible with the other components of the control system.Cooling Plant and Safetya) CranesAnnual tasks for maintenance of cranes and lifting equipments in the buildings relatedto TJ-II and auxiliary systems have been carried out.b) Cooling systemAnnual tasks have been carried out.c) Air pressure systemAnnual tasks have been carried out.d) Upgrade of the cooling system of the Electron Berstein wave heating (EBWH)system.The EBWH gyrotron has been relocated closer to the waveguide inlet. A modification ofthe water manifolds of the cooling system have been necessary to avoid some parts at highvoltage to be nearby the steel cooling tubes.e) Safety lifelineAsociación Euratom – CIEMAT .- Annual Report 2012 43

The installation of a horizontal lifeline in the TJ-II torus hall has been necessary for theaccess to the upper corridor along the building length. It was required by the inspection of theCIEMAT safety department. The crane maintenance company personnel are the main users ofthis corridor.3.5.1.1.3 INSTALLATION OF NEW EQUIPMENTGas Injection module and Diagnostics Timing SectionThe last subsystem to complete the Control System upgrade has been the GasInjection module and the Diagnostics Timing Section. This system is now fully integrated intothe TJ-II Control System. As usual, the changes have been made without interrupting theexperimental campaigns. All the software for the Gas Injection module and the Diagnostictiming section has been rewritten and tested. The old versions, written in OS9, ten years ago,have been translated to the new operating system VxWorks, adding new features based on theexperience gathered during the last years.The integration of the new software in TJ-II Control system has been easily carried outthanks to the communication middleware architecture developed by the control group (XMLbasedMessages Distribution Service, XMDS).An Apache Tomcat web server has been installed and configured to allow remoteaccess to TJ-II control system web applications. An application (servlet) hosted on the webserver has been developed to manage the flow of data and commands between two messageorientedmiddlewares (MOM), the open source named Apache ActiveMQ and XMDS developedby Control Group. The first provides distribute communication services between the server andJava applets running on a web browser, and the second one between server and TJ-IIembedded control systems. Both of them allow the communication between differentcomponents of a distributed application to be loosely coupled, reliable and safe. Additionally, itcontrols the flow information between the TJ-II control systems local network and outsidenetwork.Two new web applications for timing system, and gas puffing system, have beendeveloped using ActiveMQ middleware. HTTP communication protocol is used to send andreceive messages based on XML data streams.Fast ControlAn additional feature has been implemented in the Fast Control subsystem: a softwarecounter which keeps track of the slow timing sequence during the shots. This counter is usefulin order to relate alarms or events that occur during the TJ-II discharges with their time stamp.A new Rogowski coil has been installed outside of the vacuum vessel with the aim touse it in a feedback loop for the plasma current control through the current modulation of OH.Asociación Euratom – CIEMAT .- Annual Report 2012 44

Throughout year 2012 some of the works for the development of the PID control loop have beenstarted.Control System web pageA Web page has been developed showing the basics of the TJ-II Control System.http://www.fusion.ciemat.es/index.php?option=com_content&view=article&id=30&Itemid=463.5.2 OPERATION OF TJ-IIPlasma operation activity in TJ-II during 2012 was organized in two experimentalcampaigns. The spring campaign proceeded between 21 February and 12 June, with 39 days ofoperation and 1685 shots. The autumn campaign took place between 17 October and 19December with 24 days of operation and 994 shots. The main remarks worth mentioning asregards TJ-II operation in 2012 are:-The ECRH system has been operating routinely with a high degree of reliability.-The NBI system has operated reliably throughout the campaign.-Li coating by vacuum evaporation has been routinely used as plasma wall conditioningtechnique. An initial lithiumization process was done on 20 February, and it was repeated fivetimes along the spring campaign. Again, lithiumization was performed four times during theautumn campaign.A summary of the experimental sessions performed, along with the number of shotsallocated to each experiment/activity, is listed below:Start-up, commissioning of control and data acquisition systems and diagnostics: foursessions, including technical shots with neutral beams, with and without magnetic field andbeams on the target calorimeter: 4 sessions, 67 shotsTest of diagnostics: 2 sessions, 73 shotsECRH studies: calibration, power deposition profile (modulation), breakdown (ITPA)and ECCD experiments: 1 session, 42 shotsOptimization of NBI plasmas (experiments devoted to study the beam re-ionizationin the duct and optimize the coupling of the neutral beam to the ECH target plasma): 3sessions, 98 shotsImpurity transport in NBI plasmas. Evolution of radiation profiles driven by externalpuff: 2 session, 95 shotsAlfven activity in NBI plasmas: 4.5 sessions, 197 shotsshotsTransport studies with dynamic configuration scan in ECH plasmas: 3 sessions, 124Asociación Euratom – CIEMAT .- Annual Report 2012 45

Edge characterization and electric fields: Langmuir probes, fast cameras, electrodebiasing, auto-similar properties of the plasma edge, long-distance correlated structures: 5sessions, 214 shotsImpurity transport in ECH and NBI plasmas. Blow-off impurity injection: 5 sessions,235 shotsL-H transition and magnetic configuration scan: 5 sessions, 231 shotsPlasma wall studies: Injection of molecular beams (H, D, CH 4 ) to study hydrocarboncracking: 1 session , 37 shotsPlasma wall studies: 1 session, 22 shotsPlasma wall studies: Studies of Li sputtering inserting a sample holder with a lithiumrod in the plasma edge: 3 sessions, 116 shotsLiquid lithium limiter studies: 5 sessions, 179 shotsshotsPlasma edge transport studies with fast camera and double bundle: 2 sessions, 93Measurements of k-spectra in ECH plasmas: density scan and Dopplerreflectometry: 2 session, 84 shotsNeoclassical transport studies: validation of transport models (collaboration withNIFS and IPP Greifswald): 2.5 session, 105 shotsStudies of plasma viscosity and radial conductivity (with Langmuir probes andelectrode biasing): 1.5 session, 54 shotsECRH-driven fast electron modes: 0.5 session, 17 shotsIsland healing studies (4/2 resonance) (collaboration with NIFS: 1 session, 26 shotsConfinement studies in Deuterium plasmas: 1 session, 46 shotsMeasurement of radial correlation of density turbulence with Doppler reflectometry:1.5 session, 73 shotsImpurity transport in NBI plasmas: Poloidal asymmetry of the plasma density: 3session, 123 shotsStudy of the ponderomotive force in ECH plasmas: 1 session, 24 shotsECRH-driven suprathermal ions: 1 session, 34 shotsIon dynamics: 1 session, 38 shotsMagnetic well scan: 1 session, 46 shotsIsotope effect (deuterium plasma) :Influence on zonal flows: 2 session, 93 shotsAsociación Euratom – CIEMAT .- Annual Report 2012 46

shotsMeasurement of Te profile with X-ray diagnostic (four filter method): 1 session, 50Stray radiofrequency radiation and plasma fluctuations: 1 session, 47 shotsLow density transition: measurement of plasma potential assymetry and particletransport and radiation: 1 session, 40 shots3.5.2.1 OPERATION OF THE ECH SYSTEM3.5.2.1.1 GENERAL MAINTENANCE AND IMPROVEMENTS TASKSThe 53.2 GHz ECRH system has been working routinely with high reliability and only afew tasks concerning the improvement and the maintenance of the system have been carriedout during 2012. Among the most relevant works we may highlight the routine maintenance ofthe high voltage power supply. Two weeks during the summer shutdown were devoted to thistask.3.5.2.1.2 EXPERIMENTAL CHARACTERIZATIONThe directional coupler incorporated in the last mirror of the QTL1 ECRH transmissionline has been used to measure the wave polarization in real high EC power conditions (250 kW)and good results were finally obtained [ECRH1]. The wave reflections along the transmissionline have been further reduced by removing most of the metallic plates surrounding the beampath and which were initially acting as a safety component. Instead of covering all the line with agood microwave absorber, as the one used in the vicinity of the directional coupler, the abovesolution was adopted. However, but due to the reliable results, a drawback in the design of thecoupler was exposed. With the present design only the power in one of the channels can bemeasured with confidence.3.5.2.2 OPERATION OF THE NBI HEATING SYSTEM3.5.2.2.1 NBI OPERATIONThe two Neutral Beam Injectors have operated reliably through the experimentalcampaign of 2012. No major problems have stopped beam operation. The injection energy of31 kV and the power through the port of 550 kW have allowed operation of the Ion Sources in asmooth and safe way [Pulsos_Inyeccion_2012]. This situation was considered a good startingpoint to undertake an upgrade of the High Voltage Power Supplies aiming at increasing theinjected energy up to 35 kV, which is the limit set by the High Voltage tetrodes of the Accelpower supplies. The work on the Injector#1 HV power supplies was carried out in January 2012,and conditioning of the ion source followed in the first weeks of 2012[MejorasFA_Accel_120206]. The highest attained parameters were 35 keV energy, 750 kWpower. But operation of the high voltage tetrodes was unstable at this point and therefore theworking ion source parameters were set at lower values (33 kV energy, 700 kW power).Asociación Euratom – CIEMAT .- Annual Report 2012 47

Beam operation was made more user-friendly with the upgrades introduced in the userinterface panels. The high voltage alarms and interlocks are integrated in the interface panelsmaking it easier to trace the problems in the power supply areas.Beam-plasma coupling was still difficult for beam#2 during the first semester of 2012,even after the duct cleaning carried out in the summer 2011 and the subsequent beam ductconditioning. The weak beam –plasma coupling for NBI#2 was due to the combined effect ofpoor beam transmission (strong reionization losses) and the high load to the plasma from thegas and impurities re-emitted from the duct walls. From January through June 2012 Beam#2plasma operation was alternated with duct conditioning pulses (in the absence of plasma). InMarch the situation reached an optimum and no further improvement could be achieved inbeam transmission or wall gas re-emission [ResumenDuctos_120420].The decision was taken to dismount the duct#2 during the summer 2012 in order toperform a thorough surface cleaning and substitute the graphite protection plates with stainlesssteel plates of exactly the same design. This task was carried out through July and August, andthe new duct put to the test in October. After a small number of conditioning shots the pressurerise was reduced to 3 10 -4 mbar (half the former value), and the upper reionization limit reached20% (a 30% reduction compared with the lithiumized graphite duct) [Acond_Ducto#2_121016].During the last quarter of 2012 plasma operation with Beam#2 showed greatimprovement with relation to density control and beam energy coupling.Injector #1: Beam InjectionInjector #1 was available for injection from January through December 2012. Recordbeam parameters were 33 kV energy, 700 kW through-port power, tbeam ≤ 120 ms. Thenumber of pulses per day ranged between 20 and 40 (record number 50 pulses/day).[Pulsos_Inyeccion_2012]Injector #2: Beam InjectionInjector #2 was available for injection from January through December 2012. Beamparameters were 31 kV energy, 550 kW through-port power, t beam ≤ 120 ms. The number ofpulses per day ranged between 20 and 40 (record number 44 pulses/day).[Pulsos_Inyeccion_2012]Reionization at Injector#2 DuctThe lithium deposits from the faulty lithium oven (later removed from its original locationover the duct of NBI#2) could not be completely cleaned from the duct metallic walls and thegraphite protections in the summer 2011, therefore beam#2 operation until the summer 2012was characterized by a high re-emitted gas flow under beam particle impacts. A set ofdiagnostics installed in the duct was used to monitor the progress in duct wall conditioning[ResumenDuctos_120420]. Fast Ion Gauges (FIG) provided the pressure evolution at the ductexit during NBI pulses in the absence of magnetic field. The pressure showed a steep riseAsociación Euratom – CIEMAT .- Annual Report 2012 48

during a 100 ms pulse reaching values near 8 10 -4 mbar even after an intense duct conditioningperiod. At the beam#1 clean duct the pressure rise was half that value for the same beamparameters. Infrared cameras were used to estimate an upper limit for the reionization lossesusing the ratio of the peak temperatures at the graphite beam stop for pulses with/withoutmagnetic field. In June, this upper limit was 30% for beam #2 and 20% for beam #1. Visiblespectroscopy was performed along a line of sight parallel to the beam: the spectral lines ofatomic Li and O testified of remaining lithium compound deposits on the duct #2 wall. Thebolometer arrays looking on the beam #2 entrance showed a pronounced beam attenuation forbeam pulses with magnetic field, implying that a significant beam fraction was deflected beforereaching the plasma [UP&DOWN NBI (Marian)]. A beam blocking case has been documentedwhere a duct pressure surge over 10-3 mbar caused a near complete beam loss[SOFT2012_poster_NBI_Duct].Finally, the infrared images focused on the duct exit showed the hot spots produced bythe impacts of reionized neutrals on the duct walls [Ducto#2CIR_BvarUyD_110622]. Thelocation of these hot spots is in good agreement with the expected intersections of the iontrajectories with the duct walls, as calculated with the new ion trajectory code TRAYN[Semin_Reion_TRAYN_120127]. After the thorough clean up of the duct surfaces and thesubstitution of the graphite plates with stainless steel plates in the summer of 2012, the gas reemissionand the injection of impurities were strongly reduced, and the coupling of beam energywith the plasma showed great improvement [Acond_Ducto#2_121016].3.5.2.2.2 ION SOURCE CONDITIONINGIon Source #1: conditioningConditioning of the Ion Source after the Christmas break was carried out in a single dayof work with the Motor Generator providing 15 kV in a continuous mode. The Arc instabilityknown as “Flip mode” was intermittently present, and seemed to be alleviated only throughconditioning at longer pulse lengths.After the summer pause the Ion Source filaments had to be replaced, and subsequentconditioning took three weeks. The gas injected into the ion source had to be re-adjusted inorder to get rid of the flips and increase beam parameters.Ion Source #2: conditioningIon Source conditioning was made in a single day of work after the Christmas break.After the summer pause, conditioning of the ion source to full parameters took 6 days of workwith the Motor Generator providing 15 kV in a continuous mode. Flips seldom appeared, andonly high voltage breakdowns were a moderate problem.3.5.2.2.3 NBI MAINTENANCEIon Sources (laboratory)Asociación Euratom – CIEMAT .- Annual Report 2012 49

Grids curvature: a die has been designed with the proper curvature (R= 4 m) andmachined channels to keep the grid cooling tubes safe. It has been manufactured at theCIEMAT shops. Anode 2 flange: a new aluminium anode2 flange has been designed with a minioptical flange to allow observation of the grids with a visible camera. It has been manufacturedat the CIEMAT shops.Injector #1: MaintenanceIn July, the beamline and ion source were vented with N2 and kept under inertatmosphere for two months. Only a rapid intervention was carried out in the calorimeterchamber, to remove the supports of unused thermocouples and avoid degasification underbeam particle impacts.a) Ion SourceThe electron-emitting filaments of Ion Source #1 had to be replaced in October after twoyears of operation.b) BeamlineIn October, the water flow through the pumps was lowered from 4.5 l/h to 2.3 l/h, thesame value as NBI#2 Ti pumps, were a consistently higher pumping speed has beenmeasured. The pumping speed improved significantly as a result of this action: the pumpingtime constant has decreased from 85 ms to 50 ms. The vibration associated with the higherwater flows was likely the cause of a poor titanium adherence on the aluminium panels.Injector #2: MaintenanceIn July, the beamline and ion source were vented with N2. The ion source was keptunder inert atmosphere for two months. The beamline was opened to the air at the duct end forinterventions at the isolating valve V2 and the duct protection plates.a) Ion SourceNo intervention has been necessary. The presently working filaments were installed inDecember 2009.b) BeamlineThe duct was completely disassembled. The isolating valve V2 was sent to themanufacturer (VAT) for repair. The duct coupling piece was thoroughly cleaned off the lithiumdeposits. A new set of protection plates were manufactured at the CIEMAT shops. They aremade of stainless steel and their mechanical design is almost identical to the discarded graphiteplates. The new plates were installed on their supports with their attached thermocouples[Acond_Ducto#2_121016].Control & Instrumentation systemA new UPS has been installed in the refrigeration control system to replace the old,faulty one. Repair work has been performed on a number of broken electronics boards.Asociación Euratom – CIEMAT .- Annual Report 2012 50

Power Suppliesa) General maintenanceDuring the winter and summer breaks preventive maintenance works are carried out onthe electrical installations. The maintenance tasks are performed by house staff whereas theinspection and audit tasks are carried out under contract by external companies as EMTE insummer and TUV in winter.b) High Voltage tablesThe old capacitors installed on the Intermediate electrode, Cathode, Arc, Filament andMagnet power supplies of both Ion Sources have been replaced. A certain improvement hasbeen observed in the behaviour of the “flip mode” arc instabilities.Titanium pumpsIn March, the titanium wires of the Titanium gettering pump NL#1 had to be replaced. InSeptember, the titanium wires of the Titanium gettering pump NR#1 had to be replaced. Onlythe external electrical connectors were switched to the spare wires, no internal intervention wasneeded.Cooling systemThe Yokogawa flowmeters on the Ti Pumps and Injector returns were not workingproperly. They had lost electrical insulation to the metallic structure. They were disassembledand sent for repair and calibration. New supports were manufactured to ensure properinsulation and avoid ground loops.Target CalorimeterThe thermocouples embedded in the copper buttons, used as reference for the incidentpower density, showed a slow time response probably due to a bad thermal contact. In order toensure adiabaticity new coupling fixtures were designed to improve thermal contact betweenthermocouple and copper button, and provide thermal insulation between the copper button andthe metal structure.3.5.2.2.4 NBI UPGRADESPiezoelectric valvesAfter a thorough search in the market for new piezoelectric valves proved unsuccessful,a significant effort was devoted to the reconstruction and calibration of old, broken piezoelectricvalves to create a stock of good, working spares. As a result, two piezoelectric valves are nowin stock for ion source gas injection. A new solenoid valve (Inficon VDM005A-X; Gas FlowRange: 1000 sccm ) has been purchased to be used at the neutralizer gas injection lines. It hasbeen checked and calibrated in the laboratory.High Voltage Power Supplies (Accel Grid):Asociación Euratom – CIEMAT .- Annual Report 2012 51

In January the capacitors in the rectifiers 1 and 2 of NBI#1 were replaced. In Septemberthe capacitors in rectifiers 1 and 2 of NBI#2 were also replaced. The changes made on the HighVoltage rectifiers were intended to reduce the voltage drop during beam pulses at the Accelpower supplies. A reduction from 9 kV to 5 kV was experimentally confirmed on both injectorlines. Both rectifiers have been working fine since then and the operational reliability hasimproved thanks to the fact that the voltage differential applied on the Ion Source acceleratorgrids has been reduced by 4 kV. It also means that we have now the possibility to raise ourbeam power without having to over-stress the tetrodes in our HV plant[MejorasFA_Accel_120206].Control of the High Voltage power supplies is currently performed by the original PLCsystem through an old version of Siemens WinCC Interface Software installed in an old PC. It isforeseen that these tools will soon become obsolete and their maintenance abandoned by theprovider. After studying several options it was decided to use the OPC software which permitsthe communication with the PLC and a Labview program developed by us as the controlinterface with the power supply plant. Those new tools are installed on a new Windows 7 PC.Arc Power SuppliesThe ARC supply protections located in the NBI transformer vault in the basement arefrequently tripped. To facilitate the restoring actions 4 direct-acting motor operators have beeninstalled for rearming those protections remotely from the NBI control-room. They are fullyoperative at present.Control & Instrumentation systema) Control user interfaceChanges initiated last year to make the interlock panel of our man-machine interfacemore user-friendly were successfully validated. Failures from the interlock system can nowclearly be identified from the interface and it is therefore more straightforward to trace down theorigin of the faults and restore operation. The Vacuum system panel is being reviewed as wellto incorporate the latest modifications carried out on the system. A list of improvements wasestablished and passed on to two programmers for their integration into the interface.b) Signal transmissionFifty voltage-to-frequency modules were received. Installation was slightly delayedbecause one component did not behave as expected. Fortunately a practical as well asaffordable solution was found to solve the problem. Some modules are now gradually beinginstalled in the NBI control system to replace older and less reliable models. Other modules arebeing delivered within the Fusion Department to the Electron Cyclotron Heating Group, theHeavy Ion Beam Probe Group and the TJ-II Electronics Group. The Accelerator TechnologyUnit from the Technology Department has also shown some interest in using the voltage-tofrequencyconverter. The module documentation has been published as an official CiematTechnical Report [UOA1_VF_FV_Converter].Asociación Euratom – CIEMAT .- Annual Report 2012 52

Test results from the first pair of production voltage-to-frequency modules were quitedisappointing. The module was generating 250 mV p-p transients into the analogue input andoutput signals. As the prototype modules did not exhibit that noise the origin of the problemcould quickly be traced down to the upgraded version of a DC/DC converter which was notbehaving as expected.With 400 of those components already delivered there was pressure to find a way tomake them work adequately. Numerous application notes and detailed information from DC/DCconverter manufacturers were studied and an efficient way to suppress the switching noise wasfinally found. This could be achieved by inserting a common mode rejection filter in the supply ofthe DC/DC converter. In its surface mounted format the filter was small enough it could be fittedbetween the printed circuit board and the DC/DC converter and no further changes wererequired. And compared with other alternatives the common mode rejection filter was by far thecheapest option with only a 3.5% increase from the original cost. Eventually the filters wereinstalled on all our existing modules.c) DatabaseThe program Upload_FUSC making several NBI signals available from the fusc2 serverto all TJ-II users has been developed and is now fully operative [SEÑALES NBI_FUSC2].d) Piezoelectric valves controlThe new power supply UPS9 (prototype) is in the test phase. It will be used to operatethe gas valves. It is a configurable source, supplying DC voltage for short pulses, with twocontrol inputs and an interlock system.Beam Diagnosticsa) Visible camera for grid breakdown monitorizationWhen performing Ion Source conditioning a serious problem is that operation is “blind”in the sense that there is hardly any real-time feedback from within our Ion Sources. Thepossibility to actually “see” the grids would help in localising and explaining problems, andtaking the appropriate decisions. Different options were envisaged and eventually, as a startingpoint, the cheapest solution was selected. A small 120 frames per second camera was bought,installed and successfully tested in situ. Preliminary results have confirmed that the images arenot disturbed when voltage breakdowns occur between the accelerator grids and that moreeffort can be invested into this new diagnostic. A new flange with a peephole has been orderedand should be delivered early in 2013.To get images in real-time from the inside of the Ion Source is not as trivial as it seems.During operation the Ion Source is raised to 40 kV and some galvanic isolation is required to beable to visualise images at ground potential. A coherent optical fibre bundle was to be used tobring the image to one of TJ-II existing fast camera. But commercially available bundles aredelivered with metallic outer sleeves that made them inappropriate for our particular application.And to have one specially made to our specification would have been too expensive. AnotherAsociación Euratom – CIEMAT .- Annual Report 2012 53

option was to fit a camera directly next to the Ion Source and find a way to transmit the videosignal via optical fibres. In that case the camera would be exposed to strong electromagneticinterferences provoked by electrical breakdowns between the grids of the Ion Sourceaccelerator. As it was not clear whether the camera would survive such treatment nor that theimages would be exploitable during those events, a 350 € camera was therefore chosen to setup the new diagnostic. Its 120 frames per second recording rate is not as quick as we wouldhave liked but it should at least allow us to find answers to our questions without having to takeat this early stage any inconsiderate risks.b) Infrared camera for Beam#1 duct monitorizationA new infrared camera immune to magnetic fields has been purchased (PI160 deOptris), for use in the NBI # 1 duct to monitor the beam-wall interaction areas and estimate thereionization fraction. It is in the testing phase.c) Pressure measurements: Fast Ion Gauge (FIG)FIG’s of the Bayard Alpert type are installed in the Beam Box and duct of both injectors.The FIG in the Beam Box is used to evaluate the pumping speed of the Titanium getter pumps.The effective pumping speed as measured from the Beam Box is around 120.000 ls-1. The FIGin the duct end is used to monitor the pressure during beam pulses without magnetic field, andthus infer the gas re-emission rate from direct beam impact on the duct walls. Due to itsproximity to the machine, the measurements with FIG´s in the ducts are affected by the residualmagnetic field from TJ-II during plasma pulses. Such pressure measurements are needed toevaluate the gas re-emission rate from wall surfaces hit by neutral beam particles as well asreionized ions, and thus estimate its effect on plasma fuelling. Several trials have been made toshield the gauges from the magnetic field. Concentric cylinders made of an internal layer of mumetaland one or several layers of iron have been unsuccessfully tried.Cold cathode pressure gauges of the Penning type are a promising option for fastpressure measurements under a magnetic field. A new gauge has been purchased and firsttests are under way.Asociación Euratom – CIEMAT .- Annual Report 2012 54

4 EMERGING TECHNOLOGIESDEMO4.1 DEVELOPMENT OF MATERIAL SCIENCE AND ADVANCED MATERIALS FOR4.1.1 FUNCTIONAL MATERIALS4.1.1.1 PRODUCTION OF ADVANCED LI SILICATESThe synthesis of the Li 4 SiO 4 was carried by a Mini spray-dryer Buchi B-290 using 0.4 Msilicon tetra-acetate and lithium acetate as starting solutions followed by pyrolysis at 200ºC. Thespherical particles obtained have to be calcined in order to reach the satisfactory phasefollowed by pirolysis. It was necessary to found a compromise between the adequate sphericalmorphology and the presence of an unique phase. It was possible to have a compound withoutsecondary phases at 700ºC, however such temperature was not able to preserve the adequateshape of the spheres. The best compromise was obtained at 600ºC where a small amount ofLithium carbonate remains.The study of the Li + -ion diffusion on the sintered bodies was investigated by means ofelectrical conductivity measurements. The effect of the γ-ray irradiation was evaluated byimpedance spectroscopy method (EIS) from room temperature to 1173 K.It has proved that the best conducting ion species in this material is presumed to be Li +although other ions may be mobile to a certain extent. The conductivity of sintered bodies ispromoted by γ-ray. During irradiation process defects associated to charge transfer areanticipated, encouraging Li + ion mobility and conductivity process in the Breeder Blanketcandidate material. In terms of T mobility it means that the γ radiation, could help the ionhopping between vacant sites: the ones created by Li transmutation and the interstitial or vacantsites created by foreign atoms. All those phenomena will facilitate the kinetics of tritium release.The optimizations of synthesis parameters and conditions of sintering have allowed toprepare the Lithium orthosilicate according to the requirements of the BB for the thermonuclearfusion [Si SILICATE].4.1.1.2 ION RADIATION EVALUATION OF LI CERAMICS(a) Thermoluminescence changes due to irradiation or implantation of lithium basedceramicsThe dependence of luminescence signals with wavelength and temperature has beenwidely used to study imperfections in crystals. In fact, defects and their distribution in the latticeare responsible for the luminescence emission that is commonly observed in semiconductorand insulator materials during excitation with temperature, electrons, ions, UV or ionizingradiation. Thus, luminescence techniques, thermoluminescence (TL), cathodoluminescenceAsociación Euratom – CIEMAT .- Annual Report 2012 55

(CL), optically stimulated luminescence (OSL) and radioluminescence (RL), are usuallyemployed not only for the assignment of defects associated with the impurities or impurityintrinsiccomplexes, but also for dosimetric purposes.Following last year research on ionoluminescence of breeding blanket ceramicmaterials, the radiation effect of Li 2 TiO 3 ceramics sintered at 1150 and 1350ºC was studied bymeans of its UV-IR cathodoluminescence (CL) and thermoluminescence (TL) properties.Results lead us to conclude that the CL spectral emission decreases in ceramic samples withthe higher sintering temperature, which is associated with subtle changes in the lattice structure(beta-to-gamma transformation). The study of the TL response to gamma-ray dose and fadingeffect of these samples indicates that the UV-blue glow emission exhibits a saturatingexponential behaviour with dose. Additionally, successive irradiation-heating cycles give rise toa progressive increase in the TL intensity due to an increase of holes concentration inluminescence centres. [LiTiTL_2012].(b) He diffusion behaviour and transport properties on lithium based ceramics. On theeffect of ionizing or structural damage. Nuclear reaction analysis for He depth profilingOne of the key questions concerning materials for breeding blanket applications is thestudy of light ions retention, produced by transmutation reactions and/or introduced byinteraction with the plasma. In ceramic breeders the understanding of the hydrogen isotopesbehaviour (mainly tritium) to material surface is crucial. After Li transmutation in breeder solidceramics, T and 4 He diffuse along grains and grain boundaries reaching the surface where willbe desorbed. Considering the experimental difficulty of handling Tritium, Deuterium or 3 He (as aclose element with the same atomic mass and spin) could simulate its transport behaviour.Diffusion is enhanced due to ionizing radiation and occurs by different mechanism. Atleast in insulating materials, ionizing radiation induces valence changes and charged vacancies,which modifies their activation energies for diffusion. In addition, the induced damage createsvacancies enhancing also the diffusion. The effect of ionizing radiation on H isotope and Hebehaviour will be one of the main objectives to achieve on lithium ceramic materials.As preceding years, the NRA technique was used to analyze 3 He distribution onceramic matrices. 3 He was chosen as a double purpose: to simulate the T release and 4 Hedepthdistribution as a Li-transmutation product. Besides, the isotope 3 He makes possible thein-depth analysis by means of the 3He(D,α)p nuclear reaction analysis (NRA): a very sensitive,quantitative and non-destructive method in the field of light elements detection. In an attempt togo a little further, experiments were also performed on previously gamma-irradiated samplessimulating the in-reactor situation where matrix elements will be damaged due to ionizingradiation.Pellet-shaped, thinned and polished lithium-based ceramic samples of about 10 mm indiameter and 200 µm thicknesses were supplied. Ceramic disks were sintered to achieve aporosity of 10-15% (90-85 % of the theoretical density). Helium diffusion experiments wereAsociación Euratom – CIEMAT .- Annual Report 2012 56

performed on the CEMHTI facility (Orleans, France) in implanted ceramics at RT using a 600keV and 2.35 x 10 16 3 He 2+ /cm 2 . Implantation energy was calculated using SRIM code to locatethe maximum at approximately 2µm. Following implantation, low temperature NRAmeasurements using the 3 He (D, 4 He) 1 H nuclear reaction were performed to characterize theinitial He depth profile. The evolution of gas concentration was analyzed during isochronal andisothermal processes. By on-line detection of emitted protons and alpha particles in coherence,the He desorption rate as a function of temperature and time was determined. Eventually,detailed NRA measurements at RT were registered to characterize modifications in the Heprofile at given temperatures. Preliminary results allow concluding however important facts: Herelease is only effective from 500°C, furthermore the NRA profiles being quite similar at RT and150ºC. The yield of remaining helium at 900ºC is 7.5 ± 1.3 %. [HeNRA_2012]. Some Li 2 TiO 3ceramic discs were also previously gamma ray irradiated at CIEMAT up to 4 MGy. Recentresults are now under discussion and compared with the as-received situation.(c) Electrical behaviour of γ-irradiated Li-based ceramicsMolecular dynamics simulations and experimental studies have proven that in Li-basedoxide materials Li-ion conductivity is in close relationship with tritium diffusion. A first approachto the light ion diffusion and mobility comparing two well-known candidate ceramics (Li 2 TiO 3 andLi 4 SiO 4 ) for future fusion reactors as ITER or DEMO was performed, the study being completedwith experiments on new compositions with higher Li:Si proportion (Li 6 SiO 5 ). Li + mobility wasstudied by EIS (Electrical Impedance Spectroscopy) in as-prepared and γ-irradiated samples inan attempt to find modifications introduced by irradiation-induced defects. The results suggestan increase in energy activation values for electrical process and a saturation level of defectsdue to γ -irradiation as Li content is enhanced. [SOFT_555_ 2012].4.1.1.3 CORROSION AND COMPATIBILITY OF LI SILICATESCorrosion tests have been performed on EUROFER97 steel in contact with ceramicbreeders (Li 4 SiO 4 ) in vacuum (~ 3x10 -3 mbar) atmosphere at 550ºC up to four months. Inaddition, the corrosion susceptibility of this alloy has been evaluated in a mixture of He+H at550ºC during the same periods than the first set of tests.The microstructural investigations by Scanning Electron Microscopy (SEM) and HighResolution Transmission Electron Microscopy (HR-TEM), and analyses by Energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) performed in the samples exposed invacuum atmosphere have shown that the EUROFER97 steel suffers corrosion when it isexposure to a mixture of lithium silicates at 550ºC in vacuum. The corrosion process leads tothe formation of a double oxide scale (0.65-0.7 nm width) enriched in Cr and Fe. These resultssuggest that the corrosion mechanism could be attributable to leaching out of these alloyingelements under the formation of non-adherent layer. The obtained results have been compiledin the paper “Corrosion susceptibility in Lithium ceramic breeders”of T. Hernández, P.Fernández and R. Vila, that has been submitted to Journal of Nuclear Material.Asociación Euratom – CIEMAT .- Annual Report 2012 57

A uniform double oxide layer has also been formed during corrosion tests in He+Hatmosphere. The nearest layer to the base material is compact and is depleted in iron andenriched in chromium. In contrast, the outer zone exhibit lower density and the chemical thereinis reversed to that chromium becomes negligible. The corrosion attack starts with Fe-dissolutionby dealloying process follow of the formation of different Fe and Cr oxides scales which seemsto limit the corrosion attack. The mechanism of corrosion corresponds to an inverse dealloyingwherein the dissolved element is nobler. This phenomenon can be explained considering kineticaspects and the Gibbs-Thomson effect. The obtained results have been compiled in the paper“Effect of Environment on the Corrosion of EUROFER-2 by Solid Lithium Breeders (Part I)” of T.Hernández and P. Fernández, that has been submitted to Corrosion Science journal.4.1.2 CERAMIC INSULATORS4.1.2.1 RADIATION EVALUATION OF SILICA GLASSESThree types of silica with different OH and impurity content (KU1, KS-4V and Infrasil301) have been irradiated with high energy Si +4 (24.37 MeV) and O +4 (13.5 MeV) ions atdifferent fluences (from 5x10 12 to 1.6x10 15 ions/cm 2 ) at a current of 45 nA at CMAM (Centre forMicro Analysis of Materials, Madrid). The ionoluminescence (IL) spectra were recorded during theirradiations and important changes in the IL spectra of different silica grades were observed atlow fluences. When the irradiation finished at fluences at which the detected IL was maximum(~ 1x10 13 to 5x10 13 ions/cm 2 ) we have observed cracks in all the silica samples studied, but nomacroscopic craks were observed when samples were implanted at higher fluences (5x10 14 to1.6x10 15 ions/cm 2 ). The measurements were repeated at a lower current (1nA), to avoidpossible heating of the samples, the result was similar, the cracks were produced at lowfluence. The cracks could be due to a maximum of certain defect concentration (with maximunof IL intensity) produced by electronic excitation and to changes in the physical structure at thebeam-off, which induce local changes in density. Relaxation of the lattice or recombination ofdefects seems not possible if the irradiation is stopped at certain fluence4.1.2.2 IONOLUMINESCENCE CHARACTERIZATION OF LIGHT IONS ON INSULATORMATERIALSThe surface electrical conductivity and light emission measurements for variousaluminas during 45 keV He implantation performed during the year 2011 indicated a clearcorrelation between the evolution with dose of common emissions identified as F + and F centres(oxygen vacancies) and the electrical degradation, where major changes in the emissionintensities coincide with the onset of the observed conductivity increase. However, the shorttime (ion dose) in which these luminescence phenomena take place, and the very low levels ofinitial surface conductivity make the experimental procedure and hence interpretation of theresults difficult. Furthermore lack of stability in the ion beam uniformity and intensity added tothe difficulties. To overcome these limitations, during the year 2012, both the electricalconductivity and the IBIL optical systems have been improved, allowing measurement of lowerAsociación Euratom – CIEMAT .- Annual Report 2012 58

surface conductivity and light collection from a well defined area. With these enhancementsmeasurements of IBIL and surface electrical degradation can be performed at lower ion doserates (≤ 4x10 12 ion/cm 2·s), using a defocused beam. This not only improves the beam uniformityand stability, but also slows down the processes involved. In addition the incorporation of anoven permits data to be obtained at temperatures from about 20 to 650 ºC.With these modifications measurements of surface electrical conductivity and IBIL havebeen made for 3 aluminas and sapphire at temperatures up to 400 ºC [IONOLUMINISCENCE1]. Given the practical aim of this work, the possibility of radiation induced damage annealing bypost irradiation thermal treatment in vacuum and air has also been examined, to assess thefeasibility of in situ recovery of electrical surface degradation. The results obtained indicate thata limited improvement can be achieved and that it is possible to qualify the recovery by IBIL.4.1.2.3 CHARACTERIZATION OF H AND HE ON INSULATING SURFACESPreviously deuterium loaded Macor ceramic (SiO 2 46%, Al 2 O 3 16%, MgO 17%, K 2 O10% and B 2 O 3 7%.) was characterized in terms of thermostimulated desorption (TSD)measurements. Macor samples were deuterium loaded for 2 and 25 hours and then each ofthem was heated from 25 up to 450 C in order to perform the corresponding TSDmeasurements. A Macor sample was irradiated at 25 C making use of another irradiationchamber which permitted first vacuum evacuation and then to pressurize with deuterium gas. Inthis way the Macor sample was 1.8 MeV electron irradiated being exposed at the same time toa 1.2 bar deuterium atmosphere in order to evaluate the radiation induced deuteriumabsorption. After two hours irradiation the sample was heated up to 450 C to obtain the TSDspectrum. Finally another Macor sample was first deuterium loaded for 2 hours, then heated upto 50 C and then 1.8 MeV electron irradiated for 2 hours at 500 Gy/s. After irradiation thesample was heated up to 750 C in order to obtain the TSD spectrum. The results indicate thatelectron irradiation enhances the stabilization of deuterium on the surface of Macor ceramic.4.1.2.4 RADIATION EFFECTS ON MAGNETIC SENSORS AND CABLESIn this field, the objective of task was to determine the TIEMF (thermally induced emf)and basic electrical properties of a set of mineral insulated cables. These cables (with one to 4wires) would be used to connect the magnetic diagnostic coils (in-vessel) with the measuringsystem. The TIEMF values found have been compared to previously characterized ones atCIEMAT and these values indicates that these cables have very good quality (except for onetype) if they are used in twisted pairs configuration. Basic electrical characterization includesinsulation resistance and resistance of the wire. Very good insulation and nominal conductivityof Cu were found.All the results have been compiled in a report. “Final Report on Mineral Insulation CableThermally-Induced EMF (TIEMF) and basic electrical tests”. R. Vila.Link : https://user.iter.org/?uid=FPZGZP&version=v2.0Asociación Euratom – CIEMAT .- Annual Report 2012 59

4.1.2.5 RADIATION EFFECTS ON OTHER IR/VIS DIAGNOSTICS COMPONENTSActivity continued on the detailed revision of radiation effects in optical components(windows and mirrors) and the definition of a work plan. In this general WP, some activitieshave been selected as CIEMAT activities (considering capacities and cost). Once the firstmaterials have been chosen, invoices for material purchase have been sent (as for example forKU1 provision).There was also some initial approach to Spanish companies and R&D centres to shareknowledge in this field and new materials possibilities. Some of the initial agreements will be theobject of R&D work during 2013.4.1.2.6 DEFINITION OF MATERIALS REQUIREMENTS IN DEMO: CERAMIC INSULATORSDielectric materials may be required for numerous diagnostic and H&CD systems andcomponents including NBI, ICRH, LH, and ECRH heating systems, RF windows and supports,magnetic coils, feedthroughs and stand-offs, MI cables and wire insulation. For theseapplications the main thermophysical properties of immediate concern (i.e. at the onset ofoperation) are electrical resistance, dielectric loss and permittivity, and thermal conductivity.With operation time (dose) for materials which can satisfy the thermophysical propertyrequirements, possible degradation of mechanical strength must be considered. For theelectrical resistance, usually discussed in terms of electrical conductivity, RIC, RIED, andsurface effects are the prime concern, while for the AC/RF applications dielectric loss andpermittivity from Hz to GHz must be considered.During 2012 it has collected the results obtained in different insulating materials thatcould be viable as well as the needs and requirements in R&D.4.1.3 NANOSTRUCTURED ODS FERRITIC STEELS DEVELOPMENT (ODSFSTASK AGREEMENT)4.1.3.1 MICROSTRUCTURAL CHARACTERIZATION OF ODS/FECR ALLOYSThe objective of this subtask has been the fabrication of nano-grain sized model ODSferritic steels at laboratory scale with composition Fe-14Cr-2W-0.3Ti-0.24Y (wt %). Two batchesof samples with target composition have been produced by mechanical alloying of elementalpowders and subsequent consolidation by Hot Isostatic Pressing (HIP). One of the batches wascharacterized in the as-HIP condition and after being submitted to different thermal treatments,and the other batch was forged. Microstructural characterization was performed by SEM andTEM microscopies and Atom Probe Tomography (APT). The mechanical characterization of thematerials has been performed by Vickers microhardness measurements and tensile and Charpyimpact tests. The main conclusions of the work are:-> Two batches of Fe-14Cr-2W-0.3Ti-0.24Y were successfully produced by mechanicalalloying + HIP.Asociación Euratom – CIEMAT .- Annual Report 2012 60

-> The mechanical properties of the material in as-HIP state and after being submittedto different thermal treatments (900―1300 o C, 1 h, vacuum) were analyzed.-> The as-HIP microstructure is highly unstable.-> Nanometric particles containing Y were observed in the as-HIP material.-> The mechanical properties strongly depend on the heat treatment temperature.-> Heat treatments at T>900 o C appear to improve the mechanical properties.-> A high dispersion in the Charpy impact results was observed for the material as-HIP+1180 o C.The description of the work is detailed in the WP12-MAT-01-ODSFS-01-01/CIEMAT/BSEFDA report. These studies also have resulted in the publication of several scientific articles injournals as Journal of Nuclear Materials [ODSFS_1], [ODSFS_2] and contributions inworkshops and conferences (Fusion Materials Topical Group. MAT-ODSFS: Nano-structuredODS Ferritic Steel Development (EFDA). Garching (Germany) 06/02/2012 and Ljubljana(Slovenja) 18/06/2012; Materials for Fission and Fusion Group weekly meeting. OxfordUniversity (UK) 17/08/2012 or ‘Workshop on ODS alloys for nuclear applications’. OxfordUniversity (UK) 24-26/09/2012.The microstructures of the Fe-14Cr-2W-0.3Ti-0.3Y 2 O 3 and Fe-14Cr-2W-0.3Ti-0.24Y (%wt) have been investigated by SEM and TEM techniques and tensile and Charpy impact testshave been performed. A homogeneous dispersion of oxide nanoparticles was observed in theODS alloys, and the tensile properties were enhanced in comparison to the Y 2 O 3 free alloy. Theobtained results demonstrate that the powder metallurgy route applied in the present work canproduce ODS ferritic Fe-Cr alloys with enhanced microstructure and mechanical properties.TEM analyses showed the presence of several Cr-rich and Y-rich phases in the steels. It wasfound that some of the Y-rich nanoparticles retained their initial structure but developed a Crenrichedshell, while others evolved into complex oxide phases [Microstructure_ODS].The C and O contents were quantified using LECO analyzers: CS600 (combustion andinfrared detection) for C and TC500 (solid-state infrared and thermal conductivity detection) forO. Very low C content is detected, i. e. 0.040 ± 0.002 (wt %), however the O content is high:0.773 ± 0.003 (wt %). These results are very similar to those obtained for the as-milled powder,so it seems that impurities incorporation, especially O, occurs mainly during the mechanicalalloy process and not during the canning, degassing and HIP consolidation.Preliminary atom probe tomography (APT) results were obtained in the Fe-14Cr-2W-0.3Ti-0.24Y steel in as-HIP state. The three-dimensional reconstruction of a 40×40×400 nmvolume has been achieved. The Y ions are located in the 283 nano-clusters dispersed in thereconstructed volume. Detailed analysis of these clusters is currently underway. Ti-rich clustershave been found with the next characteristics: i) the cluster size is estimated to be around 30Asociación Euratom – CIEMAT .- Annual Report 2012 61

nm and ii) no presence of Y or W in this Ti-rich cluster. This observation agrees with the TEManalysis [Microstructure_ODS].Positron lifetime measurements (PL) and coincidence Doppler broadening (CDB)technique experiments have been performed to characterised a series of oxide dispersionstrengthened (ODS) ferritic steels with nominal compositions (wt. %) Fe-14Cr-0.3Y 2 O 3 , Fe-14Cr-2W-0.3Ti-0.3Y 2 O 3 , and Fe-14Cr-2W-0.3Ti-0.24Y and reference Fe-14Cr. PL and CDBexperiments have been performed on these alloys at different stages of the processing route inorder to identify the nature of the defects present in the materials. Moreover, samples havebeen subjected to isochronal annealing to study the thermal stability of the defects and identifytheir recovery stages [POSITRON_ANN.].The mechanical properties of the produced steels as-HIP and afterHIP+forging+thermal treatment (F+TT) have been study as a function of the temperature. Theeffect of the applied temperature can be clearly observed as only the as-HIP Fe-14Cr-2W-0.3Ti-0.24Y (14YWTi-Y) samples heat treated at temperatures in the range 1150-1300 o C showductility. Opposite behavior occurs for uniform elongation and fracture elongation, as 14WTi-Ysamples heat treated in the range 1150 – 1300 o C show the higher values, equaling or evensurpassing 14WTi-Y2O3 values. 14WTi-Y samples as-HIP and heat treated at temperatures upto 1100 o C show higher yield stress and UTS values than the 14WTi-Y2O3 F+TT material, whileYS and UTS are lower for samples heat treated at temperatures in the range 1150-1300 o C[ODS_Oxford].Charpy impact tests of the 14YWTi-Y are under way. Preliminary tests of the material atas-HIP condition and after a heat treatment at 1180 o C (1h, in vacuum) were performed at roomtemperature and at T ~ 100 o C using a 25 J pendulum. The as-HIP material shows a fragilebehavior at room temperature and at 100 o C. The sample heat treated at 1180 o C exhibited ahigh dispersion in the energy values (0.93 − 6.01 J) at room temperature. This completelyfragile or completely ductile behavior is also confirmed by the fractography. Other heat treatingtemperatures are also being studied.4.1.3.2 RADIATION EFFECTS ON ODS STEELSThe aim of this work was the microstructural characterization of ion implanted ODS andreference Fe-12wt%Cr model alloys by TEM Microscopy, in order to determine the effect ofirradiation on the grain and dislocation structures, oxide nanoparticles and other secondaryphases present in these materials. The alloys were implanted at the JANNUS facility. Two RTirradiations were performed: a single Fe irradiation up to 10 dpa and a simultaneous tripleimplantation up to 4 dpa. The results obtained from these measurements have been analysedand compared to the ones previously obtained for the same alloys before implantation[ODSFe12Cr_1]. The main conclusions of this study are the following: (1) the grain structuresand dislocation distributions of both alloys were unaffected by the irradiations. The maindifference was the presence after irradiation of loops. For the single irradiation, most of themAsociación Euratom – CIEMAT .- Annual Report 2012 62

elow 12 nm in diameter, being the loop sizes smaller for the ODS alloy. (2) Some of the grainboundaries were enriched in Cr, having a similar behavior as the one observed before theirradiations. (3) With respect to the Cr-rich phases present in both alloys, Cr-rich carbides andoxides were present after irradiation. Their sizes, distribution and crystallographic phases aresimilar to the ones found before the irradiations. (4) With respect to the Y-rich phases present inthe ODS alloy, no significant changes on particle morphologies, sizes and distributions arefound after irradiation as compared to the non-irradiated ODS alloy. Regarding thecrystallographic composition of the particles, they could still be indexed as Y 2 O 3 and YCrO 3 , anda Y-rich core Cr-rich shell structure was still evident after both single and triple irradiation. As ageneral conclusion, the materials appear to be stable after both irradiations.4.1.3.3 PRODUCTION AND CHARACTERIZATION OF ODS STEELS(a) CEIT tasks:ODS FS were produced following the classical processing route, atomizing Fe-14Cr-2W-0.3Ti powder at CEIT’s lab scale atomizer, followed by mechanical alloying (MA) in aplanetary ball mill to dissolve Y or Y 2 O 3 , and HIP at 1100 ºC to obtain a full dense material.Different parameters of MA in protective atmosphere (Ar) were explored and 30 hours at 250rpm with BPR of 10:1 led to a good compromise between powder microstructure andcontamination. O uptake during MA ranged between 0.03 and 0.13 wt.%. A very fine butheterogenous microstructure was observed by FEG-SEM [ODS FS PROD_1], [ODS FSPROD_2]. Microstructural characterization of ODS phase by TEM is in progress.An alternative route that avoids MA was explored and ferritic stainless steel powderalready containing Y was produced by inert gas atomization, being its composition 14Cr-2W-0,56Ti-0,2Y and its O, C and N content 0.018, 0.014 and 0.001 wt.%, respectively. Ti lossesduring atomization were negligible (below 5%), and Y losses were reduced down to acceptablevalues (70%). Further atomizations during 2013 are being designed to obtain further reductionin Y losses by improving atomization practices. First oxidation studies performed at lowtemperature (400 ºC) to adjust O content to that required suggest logarithmic oxidation kinetics.The ultrathin metastable oxide layer found at powder particles surface will decompose duringHIP at high temperatures, resulting in Y-Ti-O nanometric dispersions.(b) UC3M tasks:ODS and non-ODS alloys with target compositions: Fe-14Cr, Fe-14Cr-0.3Y 2 O 3 , Fe-14Cr-2W-0.3Ti-0.3Y 2 O 3 and Fe-14Cr-2W-0.3Ti-0.24Y (% wt) have been produced andcharacterized. The blends of elemental powders were mechanically alloyed in a planetary ballmill under an atmosphere of either helium or hydrogen. The milled powder was analysed bySEM microscopy, EDS and laser diffraction (LD) techniques and their Vickers hardness wasalso evaluated. The alloyed powder was canned, degassed and consolidated by HIP for 2h at1373 K and 200 MPa. After consolidation, the material was forged at 1323-1423 K and finallyheat treated at 1123 K for 2h [ODS_Oxford].Asociación Euratom – CIEMAT .- Annual Report 2012 63

For the complete mechanical characterization and study of the ductile-brittletemperature transition (DBTT) of the alloy with nominal composition Fe-14Cr-2W-0.3Ti-0.24Y(wt %), two ingots were produced. The first ingot was mechanized into 40 samples for tensiletesting and 27 samples for Charpy impact tests and the remaining material was used for densitymeasurements, C and O quantification, Vickers microhardness measurements, SEM, TEM andAPT. This ingot was submitted to thermal treatments at temperatures in the range 900-1300 o Cfor 1 h in vacuum, and their microstructure and mechanical properties were analyzed. Thesecond ingot was forged at 1150 o C, but the result was not successful enough [ODS_Oxford].A detailed report of this work has been submitted to EFDA (European FusionDevelopment Agreement) inside the Nanostructured ODS Ferritic Steels Development (ODSFSTask Agreement) to fulfill the EFDA Work-programme 2012.4.1.3.4 Production and characterization of EUROFER-type steelsThe main objective of this research work has been the development at semi-industrialscale of a Reduced Activation Ferritic Martensitic (RAFM) Steel, which should fulfills thechemical composition specification and the mechanical properties specifications of theEUROFER steel quality (European reference steel for the Test Blanket Modules or TBMs).The work made by ITMA Materials Technology in this frame, started with the study ofprime candidate materials to be used within the elaboration of the steel, with the objective ofallow the economical viability of the process of production at an industrial scale, settling thedemanding compositional requirements.The process of fusion and heat in a induction furnace under protecting atmosphere(VIM) has been designed, elaborated and optimizated. More than 10 experimental qualitieshave been realized, and it has been determined the parameters of the posterior thermomechanicalprocess of lamination in hot, and also the final temper and shrink thermal treatment,which allows to reach the microstructure and the reference mechanical properties. Theprepared steels have been characterized, analyzing the results and making comparison with theEFDA specifications for the quality or reference steel EUROFER, verifying the fulfillment of this.ASTURFER® trade has been registered with the objective of identifying the developedsteels at semi-industrial scale by ITMA Materials Technology within this context.Additional studies on thermal treatments have realized for tenderizing, deformation incold, thermal treatments of recrystalization, and also, on welding, with the object of having therequired data for the fabrication of real components with complex geometries (TBMs) , fromplates of different thickness.During 2012 it has obtained results on the characterization of 2 heats of a 9Cr RAFMsteel produced in Spain [ASTURFER-01], called AF1B and AF2A, by testing small specimens.The obtained results were compared with its equivalent European, the EUROFER97-2, chosenas reference material. Both heats, produced at a pilot Plant of ITMA Foundation, present thesame production process and thermal treatment. They already show a similar tensile behaviourAsociación Euratom – CIEMAT .- Annual Report 2012 64

as EUROFER97-2, but some differences on the impact behaviour were observed, mainly due tothe presence of Al-Ta oxide particles in one of the heats. The origin of this oxide formation wasidentified and solve for the future heats production [ASTURFER_02]In summary, the main obtained results can be summarized in the following conclusions:* The AF2A of ASTURFER® fulfills the specifications [ASTURFER_03].* The lower lamination temperature produces that the AF2B does not reach the levels ofhardness, elastic limit and toughness to impact of specification.* In order to avoid the formation of mixed oxide, it is required to control the O2concentration. Mixed oxides are damaging for impact properties.* The heats AF1B and AF2A have similar properties to EUROFER97-2.* The AF1B has mechanical properties (creep) at thermal fluency very promising.* The DBTT provides to ASTURFER® a theoretical resistance under irradiation moreelevated due it has a bigger capability of path to room temperature.This activity give rise to the preparation of two PhD theses works (Ana Morán –at ITMAandDiego Rodriguez –at CIEMAT-)4.1.4 TUNGSTEN AND TUNGSTEN ALLOYS DEVELOPMENT (WWALLOYTASK AGREEMENT)4.1.4.1 BRAZING DEVELOPMENTThe work was divided in two activities: i) the first one consisted in the evaluation of thedeposition of Ti-Fe layers on W by HVOF thermal spraying; different spraying distancesbetween 100 and 250 mm were used; and between 1 and 4 layers were applied to the Wpieces; and ii) the second activity dealt with the fabrication of a flexible filler tape by mixing theTi-Fe alloys with an organic binder. In both cases, the compositions considered were Ti-86Feand Ti-46Fe. The mechanical properties of brazed samples were evaluated by means of sheartests.(a) Brazing and characterization of W-W joints using fillers deposited by HVOFThe thickness of the sprayed coatings was nearly proportional to the number of layersdeposited and porosity of the coatings was avoided in most cases. The Ti-46Fe fillers showedcracks formed during cooling caused by the mismatch of CTEs between coating and substrate,indicating that this layer is formed with more brittle compounds than those of the Ti-86Fe.Another characteristic of the coatings was the intrinsic oxidation of the sprayed powder due tothe spraying process and the oxides, mainly Ti ones, that were formed.The brazed joints with Ti-86 filler had very little tendency to join together and only localwelds were observed. This may be due to lack of melting of the filler which can be related to notbeing with the correct stoichiometry due to the partial oxidation of Ti. The incorporation of a thinAsociación Euratom – CIEMAT .- Annual Report 2012 65

Ti sheet allowed getting high continuity between the two W coated pieces. The Ti-46Fe filler didnot tend to melt, although increasing the time at the maximum temperature eased this partially.Again, the presence of oxides limited the melting of the filler and the brittle phases formedcaused the presence of cracks.Shear tests could only be applied to the joints that had a Ti interlayer as the other brokeduring the test preparation, indicating that they were not adequate. The Ti-86Fe+Ti samplesresisted up to 22 MPa, while the Ti-46Fe+Ti resisted 28 MPa.(b) Fabrication of flexible filler tapes using organic binders for W-W joiningTwo binders of organic nature based on polyacrilic acid (PAA) in water solution and onpolypropylene carbonate (PPC) in acetone as dissolvent were used for fabrication of flexiblefiller tapes. Rate of metallic/binder phases of 90:10 showed enough capability for lamination inthin tape (150 μm) and flexibility for adaptation in curves surfaces. However, the durability of thePPC based tape was lower because the quick evaporation of acetone, which reduces theflexibility and conformability of these filler tapes.Binary Ti-Fe compositions of filler tapes made with PAA binders, brazed joints with veryhigh metallic continuity and low proportion of brazeability problems were obtained. Thepresence of the binder partially inhibits the interdiffusion between powder and the finalmicrostructures of the solidified braze have a lower proportion of intermetallic phase and ahigher proportion of Fe-rich and Ti-rich ones, respectively.The fillers tapes made with PPC binders gave rise to a high concentration and localaccumulation of carbonaceous residues that inhibited the joint formation.Mechanical strengths of brazed joint using flexible fillers made with 90/10 ratio of Ti-Fepowders and PAA binder were higher than the maximum which can be determined by shearingwith the present testing configuration. Nominal shear strengths of 80 MPa, for Ti86Fe filler, and125 MPa, for Ti46 filler, were obtained in relation of the nominal cross section of the brazedspecimens4.1.4.2 W-V AND W-TI ODS ALLOYS DEVELOPMENTThe task of the UC3M group has been to produce small laboratory batches of W-2%Tiand W-1%CTi (wt.%) following a powder metallurgy route that includes sintering by HIP [W-ODS_1]. In order to determine the optimum parameters of the mechanical alloying process thatcan result in a homogeneous microstructure, the characterization of the materials along thefabrication process has been performed. The microstructure of the consolidated alloys has beenstudied by different techniques as XRD, SEM and TEM microscopies and Small Angle NeutronScattering (SANS).W-2Ti and W-1TiC alloys have been produced via a powder metallurgy route consistingof mechanical alloying during 75 h and 50 h, respectively, and a subsequent consolidation byHIP for 2 h at 1573 K and 200 MPa. The starting powders were W, Ti and TiC. The evolution ofAsociación Euratom – CIEMAT .- Annual Report 2012 66

the lattice parameters, accumulative microstrain and crystallite sizes of the powders during themilling process has been analyzed by XRD measurements and its microstructure by SEMmicroscopy. The increasing of the oxygen content has been determined by infrared absorptionand thermal conductivity. The solution of Ti and a good dispersion of the CTi nanoparticles inthe W matrix were obtained.The densification of the W-2Ti and W-1CTi alloys after consolidation by HIP were 98 %and 95 %, respectively. The Vickers microhardness resulted in a value of 14.0 (7) for theformer, and 7.0 (4) for the latter. These values are much greater than that of pure W producedby the same powder metallurgy route.The microstructure of both alloys has been studied by SEM. Both alloys present a grainsize with a bi-modal distribution: one of them with a mean value of a few micrometers and theother one with a mean value below the micron. In W-2Ti, pools of Ti with a size of a fewmicrometers uniformly distributed on the W matrix have been observed. The formation of thesepools has been associated to the segregation of Ti during the HIP. In W-1CTi, agglomerates ofCTi particles with a size of about 1 micrometer have also been observed. TEM study has shownthat TiC particles with sizes

parameters are: a) mechanical alloying during 75 hours and subsequent HIP sintering at 1573 Kand 195 Mpa for the production of W-2%Ti alloy and b) mechanical alloying during 25 hours andsubsequent HIP sintering at 1573 K and 195 Mpa for the production of the W-1TiC.The microstructure of both materials has been investigated by SEM and TEM. W-2Tiand W-1Ti present a microstructure with a bimodal distribution of grain sizes, with micrometricand submicrometric size distributions. SEM and TEM measurements indicate that themechanical alloying gets a good dispersion of TiC particles in the W matrix, although some TiCparticles form agglomerates with sizes about a few micrometers [W-Ti_ODS_SANS].SANS experiments have been done on W-2Ti and on W-1TiC. The goal of theseexperiments has been to determine the morphology and size distribution of the Ti pools in W-2Ti and to calculate the size distribution of the TiC particles in W-1Cti. The advantage of thistechnique with respect to TEM is that SANS allows us to obtain information about the bulk andnot only about a small area of the sample. The SANS experiments were carried out in the FRMII research reactor at Garching (Germany).The SANS study of W-2Ti reveals that the Ti pools with sizes between 10 and 3000 Åare distributed according to a bi-modal size distribution, with mean diameters of 62 and 1200 Å[W-Ti_ODS_SANS]. The SANS study of W-1TiC has shown that TiC particles with a nanometricsize are uniformly distributed in the alloy. This result has also been confirmed by TEMmeasurements [W-Ti_ODS_SANS].A detailed report of this work has been submitted to EFDA (European FusionDevelopment Agreement) inside the TASK AGREEMENT: WP12-MAAT-HHFAM-03 Long-termstructural materials (Title of the activity: “Production of small laboratory specimens of W-Ti andW-TiC”) to fulfill the EFDA Work-programme 2012.The oxidation resistance of W-x%V and W-x%Ti, with x=2 wt % and 4 wt %, alloys havebeen studied by isothermal thermogravimetries to determine the influence of titanium andvanadium addition on the oxidation resistance of tungsten in dry synthetic air at 600 and 700°C.The results obtained from these measurements have been analysed and compared to the onespreviously obtained for pure W ITER-grade [Oxidacion_W]. The oxide scale and cross sectionsof the samples after oxidation had been characterized by scanning electron microscopy, XRDand energy dispersive spectroscopy. Mass gain curves proved that titanium as an alloyingelement was very effective for improving the oxidation resistance while vanadium had adetrimental effect. At 600°C, the mass gain W-Ti alloy was 4.5 times lower than that of puretungsten processed by a conventional route. Beneficial effect of titanium addition on theoxidation resistance of tungsten was significantly magnified at 700°C. At this temperature, massgain was 10 times lower compared to pure tungsten. Vanadium addition accelerated even morethe high oxidation kinetics of pure tungsten and promoted the formation of detrimental volatilecomplex oxides. Microscope observations indicated that titanium addition led to thedevelopment of oxide scales more protective and denser than in pure tungsten.Asociación Euratom – CIEMAT .- Annual Report 2012 68

4.1.4.4 OXIDATION RESISTANT W-ALLOYS DEVELOPMENTThe overall objective of this task is the manufacturing by powder metallurgy of selfpassivatingbulk W-based alloys for the plasma exposed areas of DEMO to inhibit W oxidationat high temperature with release of volatile radioactive tungsten oxides in case of LOCA with airingress. Two alloys of compositions WCr10Si10 and WCr12Ti2.5 were successfully producedby mechanical alloying and HIPing in previous periods [SPW_1], [SPW_2].The results obtained during 2012 can be summarized as follow:•The MA parameters for the WCr12Ti2.5 system have been optimized. Theseparameters have been used for the production of the new composition WCr18Ti2.5. This alloywith higher Cr content is produce to check if a higher Cr concentration favours Cr diffusion andhence, the formation of a Cr 2 O 3 protective layer (as found for thin layers at IPP), instead of theprevious, less protective Cr 2 WO 6 one [SPW_2]. While 40 h MA time seems to be a goodcompromise for WCr12Ti2.5, for the WCr18Ti2.5 system this time is too short, resulting inheterogeneities in the core of the powder particles, which led to local heterogeneities after HIP[SPW_3]. Thus, further optimization of the MA parameters is required for the WCr18Ti2.5system.•The microstructure of the WCr18Ti2.5 alloy after HIP is again extremely fine withgrain sizes below 300 nm, in spite of the presence of local heterogeneities [SPW_3]. The XRDspectra of the WCr12Ti2.5 and WCr18Ti2.5 systems are very similar with only different peakintensities. After HIP the composition of the phases is close to that of the equilibrium at 1300°Cin both cases.•The production route of pre-sintering in H 2 + HIP (without encapsulation) wasexplored but the samples did not sufficiently densify after sintering so that a subsequent HIPcycle was meaningless. Taking into account the results of previous dilatometer studies, it seemsthat green densities well above 75 % are required to obtain samples with final densities aftersintering of 90 %, which can be further densified by HIP without encapsulation. In the nextreporting period compaction by CIP will be explored to check if green densities close to 80% arefeasible.•Oxidation tests on samples of composition WCr12Ti2.5 were performed at 800 and1000°C in a furnace under synthetic air, to compare the results with those performed at IPP in athermobalance setup. A thin ( 0,5 m), dense and continuous Cr 2 O 3 layer was found at thevery surface after oxidation at both 800 and 1000°C, in agreement with the findings in thinlayers [SPW_4]. There is no increase of thickness with increasing time. A Cr 2 WO 6 thicker layerwas found below the thin Cr 2 O 3 layer, and a Cr free region consisting of WO 3 was detectedbetween the Cr 2 WO 6 and the alloy. Both Cr 2 O 3 and Cr 2 WO 6 protect the alloy from furtheroxidation. Understanding of the oxidation mechanisms (thermodynamics, diffusion) requiresfurther work. The parabolic oxidation rate found in this work was about a factor of 10 lower thanthe one found at IPP with a thermobalance setup.Asociación Euratom – CIEMAT .- Annual Report 2012 69

Finally, it should be remarked that important experimental problems arose during thisperiod with two equipments, which prevented from obtaining fully dense materials after HIP andthus, from achieving a good part of the objectives proposed for this period.4.1.5 NANOSTRUCTURED ODS AND NO-ODS CU BASED MATERIALSDEVELOPMENT (HIGH HEAT FLUX MATERIALS TASK, HHFMAM AGREEMENT)New W-2wt%Ti (W-2Ti) and ODS W-1wt %TiC (W-1TiC) have been produced followinga powder metallurgy route consisting of four steps: 1) Blending of the starting powders with theappropriate compositions, 2) Mechanical alloying of the powder blends in a planetary ball mill,3) Canning and degassing at 673 K for 24 h in vacuum of the milled powder; 4) Sintering by HIPfor 2 h at 1573 K and 195 MPa. Afterwards, their composition and microstructure wereinvestigated and they were delivered to the EFDA research HHFAM-groups for studying theirmechanical properties at elevated temperatures.The produced W-2Ti has a density about 98% of the theoretical density and no porosityis observed. Optimal production parameters have been established by XRD, SEM, EDS andlaser diffraction (LD) granolumetric techniques and chemical characterization of the lightimpurities (by inert gas fusion infrared detection method, in a LECO equipment) measurementson powder samples obtained every 5h of milling time. The best production parameters are: a)mechanical alloying during 75 hours and subsequent HIP sintering at 1573 K and 195 MPa forthe production of W-2%Ti alloy and b) mechanical alloying during 25 hours and subsequent HIPsintering at 1573 K and 195 MPa for the production of the W-1TiC.The microstructure of both materials has been investigated by SEM and TEM. W-2Tiand W-1Ti present a microstructure with a bimodal distribution of grain sizes, with micrometricand submicrometric size distributions. SEM and TEM measurements indicate that themechanical alloying gets a good dispersion of TiC particles in the W matrix, although some TiCparticles form agglomerates with sizes about a few micrometers [W-Ti_ODS_SANS].SANS experiments have been done on W-2Ti and on W-1TiC. The goal of theseexperiments has been to determine the morphology and size distribution of the Ti poolsin W-2Ti and to calculate the size distribution of the TiC particles in W-1CTi. Theadvantage of this technique with respect to TEM is that SANS allows us to obtaininformation about the bulk and not only about a small area of the sample. The SANSexperiments were carried out in the FRM II research reactor at Garching (Germany).The SANS study of W-2Ti reveals that the Ti pools with sizes between 10 and 3000 Åare distributed according to a bi-modal size distribution, with mean diameters of 62 and 1200 Å[W-Ti_ODS_SANS]. The SANS study of W-1TiC has shown that TiC particles with a nanometricsize are uniformly distributed in the alloy. This result has also been confirmed by TEMmeasurements [W-Ti_ODS_SANS].Asociación Euratom – CIEMAT .- Annual Report 2012 70

A detailed report of this work has been submitted to EFDA (European FusionDevelopment Agreement) inside the TASK AGREEMENT: WP12-MAAT-HHFAM-03 Long-termstructural materials (Title of the activity: “Production of small laboratory specimens of W-Ti andW-TiC”) to fulfill the EFDA Work-programme 2012.The oxidation resistance of W-x%V and W-x%Ti, with x=2 wt % and 4 wt %, alloys havebeen studied by isothermal thermogravimetries to determine the influence of titanium andvanadium addition on the oxidation resistance of tungsten in dry synthetic air at 600 and 700°C.The results obtained from these measurements have been analysed and compared to the onespreviously obtained for pure W ITER-grade [Oxidacion_W]. The oxide scale and cross sectionsof the samples after oxidation had been characterized by scanning electron microscopy, XRDand EDS. Mass gain curves proved that titanium as an alloying element was very effective forimproving the oxidation resistance while vanadium had a detrimental effect. At 600°C, the massgain W-Ti alloy was 4.5 times lower than that of pure tungsten processed by a conventionalroute. Beneficial effect of titanium addition on the oxidation resistance of tungsten wassignificantly magnified at 700°C. At this temperature, mass gain was 10 times lower comparedto pure tungsten. Vanadium addition accelerated even more the high oxidation kinetics of puretungsten and promoted the formation of detrimental volatile complex oxides. Microscopeobservations indicated that titanium addition led to the development of oxide scales moreprotective and denser than in pure tungsten.4.1.6 SIC MATERIALS4.1.6.1 PRODUCTION OF SIC/SIC LOW TERMAL CONDUCTIVITY COMPOSITES FORDCLL APPLICATIONSDuring 2012 CEIT has made a valuable research as concerns the Dual Coolant LithiumLead Pb15.7Li blanket concept includes flow channel inserts (FCI) and SiC is the primarycandidate material. During 2012 there has been a wide parameter study at CEIT for theprocessing of porous SiC including a dense SiC coating. Two candidate porous SiC materialshave been selected for the FCI: one sintered at 1850ºC during 1 hour (C10A2.5) and anotherone sintered at 1950º C during 30 minutes (C10A7.5). The thermal conductivity at 700 ºC is 11W/mK for the C10A2.5 material and 13.5 W/mK for the C10A7.5 one. From these results, theminimum thickness required to accomplish with the DCLL design [DCLL_SiC_02] is 2.8 mm forC10A2.5, and 3.4 mm for C10A7.5.The experimental process described [DCLL_SiC_03] has been refined by introducingsintering additives. Furthermore, a dense CVD layer of SiC of about 30 m has been depositedon the porous SiC. Results on electrical conductivity as a function of temperature before andunder irradiation with 1.8 MeV electrons at CIEMAT were also obtained. Corrosion tests of thetwo selected materials with PbLi at 700°C for 1032 h are under way at IQS. The analysis of thesamples after the test is ongoing.Asociación Euratom – CIEMAT .- Annual Report 2012 71

4.1.6.2 CHARACTERIZATION OF SIC MATERIALS FOR DEMOPorous SiC was characterized in terms of Radiation Induced Conductivity (RIC) during1.8 MeV electron irradiation. Two square samples, 10mm x 10mm x 2mm in size , one with andthe other without additives , were studied. Mixed (50% and 50%) Copper and Gold central andguard electrodes were sputtered onto one 10x10 mm 2 face, and a single earth electrode ontothe opposite face to allow an electric field to be applied to measure volume and surfaceelectrical conductivity. The irradiations were made in a special chamber mounted in theCIEMAT HVEC Van de Graaff accelerator beam line, where samples mounted on a small ovenmay be irradiated in high vacuum (≈ 3x10 -6 mbar), at controlled temperatures between 15 and900 ºC. The system allows voltages of between 100 mV and 3 kV to be applied to the samples,depending on the material conductivity. In this way the different SiC samples were heated at 0.2ºC/s from 20 ºC to the required irradiation temperature to measure the volume electricalconductivities as a function of temperature, and then irradiated at 400 C with 1.8 MeV electronsat 7 kGy/s (≈ 10 -9 dpa/s on the C sublattice) up to 130 MGy and 2 x 10 -5 dpa. For each samplethe volume conductivity was measured from 20 up to 400 ºC before irradiation, then at theirradiation temperature, (before, during, and after irradiation), and again after irradiation from 20up to 400 ºC. RIC was lower than 20 S/m at 400 C and radiation induced electrical degradationwas not observed to occur for this material.4.2 MATERIALS MODELLING4.2.1 RADIATION EFFECTS MODELLING AND EXPERIMENTAL VALIDATION(REMEV TASK AGREEMENT)4.2.1.1 RATE THEORY MODELLING OF HE EVOLUTION AND ITS INTERACTION WITHMICROSTRUCTURE IN FE(a) Improving formation energies of large HenVp clustersIn order to properly predict He kinetics under irradiation, it is crucial that bindingenergies of HenVp clusters are accurately calculated. To calculate these energies, differenttechniques can be used, such as ab initio or Molecular Dynamics. However, these techniquesbecome computationally expensive as the number of defects included in the HenVp cluster toexplore increases. Therefore, a thermodynamic model that was recently presented by T.Jourdan we used for the calculus. In this model the free energy of a helium bubble is essentiallydeduced from a helium equation of state (EOS) and includes corrections to account for theconfinement of helium in a small cavity. More specifically, the free energy of a bubble containingm V vacancies and n He helium atoms can be decomposed into terms due to the Fe-Fe, Fe-Heand He-He interactions. The results obtained with Jourdan's model for two different He content,n He =4 and n He =10 against the number of vacancies in the bubble were reported in [RT_HE]. MDresults are reported for comparison. As seen, Jourdan's model reproduces well MD results,predicting the He/V ratio for which the formation energy is minimum. The binding energy of self-Asociación Euratom – CIEMAT .- Annual Report 2012 72

interstitial atoms (SIA) as a function of the He content and the number of vacancies in thebubble is also reported. The black zone of the figure corresponds to SIA that have a negativebinding energy. According to this model, loop punching, i.e. the spontaneous emission of a SIAthat has a negative binding energy, should occur for a ratio He/V~4-5, in agreement with abinitio calculations.(b) Simulating THDS experiments with new binding energiesThe formation energies calculated using the Jourdan's model were used as input of ourRate Theory model. The interactions between He and egde and screw dislocations, which arealways present in samples, were included in our model by adding the corresponding generationrecombinationterms in the rate equations. In order to test our RT model, the THDS experimentsthat were carried out by Xu and Wirth were reproduced. In this experiment, the authorsimplanted He in Fe at 5 keV in single and polycrystals at a dose of 10 14 /cm 2 with a flux of 10 11/cm 2 /s. Then, samples were annealed with a temperature ramp rate of 1 K/s. To simulate theimplantation step, the diffusion of species at room temperature was simulated using ourdiffusion model, including a constant generation rate due to implantation for He i , SIA and V. Thecomparison between the simulated desorption spectrum and the corresponding experimentaldata is reported in [RT_HE]. As one can see, our model is in reasonable agreement with theexperimental desorption spectrum. This agreement was achieved by varying the dislocationdensity (edge and screw) between 10 10 and 10 11 /cm 2 , which are typical dislocation densitiesexpected in samples that have been deformed. It is important to note that all other parameters,i.e. migration and binding energies of He-vacancy clusters were obtained by ab initio or MD andwere kept unchanged in our simulations. According to our model, stage I and II correspond tothe dissociation of He from screw and edge dislocations, respectively. Hence, the current modelsuggests that the microstructure (dislocations) could play a significant role in the kinetics of He.An analysis of simulation results reveals that stage III would be due to the dissociation of Hefrom large HenVp clusters.4.2.1.2 SYNERGETIC EFFECTS OF H AND HE IN FE(a) Modification of the model to simulate the formation of large HenVp bubbles: Fokker-Planck equation approachUnder conditions of continuous irradiation, bubbles can form and grow up to large sizes.Therefore, the approach used up so far, i.e. solving the Master equation for each cluster size,becomes computationally very expensive. This problem can be circumvented by assuming thatfor large sizes, the properties and concentration of clusters smoothly vary with size. Under thisassumption, the Master equation can be approximated by using a Taylor expansion, which leadto a Fokker-Planck equation. Using this approach, the system of n ODE reduces to one singlepartial differential equation to solve, similar to a diffusion equation but in the size space. Inpractice, for a size smaller than 100-200, we used the discrete approach solving the Masterequation for each size, and for size larger than 100-200, we used the Fokker-Planck approach.Asociación Euratom – CIEMAT .- Annual Report 2012 73

This was done to simulate both the growth of I n clusters and He n V p bubbles under continuousirradiation.(b) Reproducing experimental conditions: Fusion conditionsUsing our RT model including the simultaneous evolution of H and He, the continuousirradiation of Fe was investigate under conditions that would prevail in fusion conditions. To doso, it was chosen to reproduce fusion conditions corresponding to a DEMO-HCLL-4000 MWreactor configuration. In order to calculate the generation rate of damage and of H and Hecreated by transmutation reactions, it was used a methodology combining neutron transportcodes (MCNP5+FENDEL 2.0), activation libraries (ACAB+EAF 2007) and BCA codes(MARLOWE). Following this methodology, it was obtained for this reactor configuration aneutron flux of 1.52x10 15 /cm 2 /s, generation rates (by transmutation) of 1.75x10 12 /cm 3 /s and1.1x10 13 /cm 3 /s for He and H respectively, and a generation rate of 1.82x10 16 /cm 3 /s for SIA andvacancies. Using these generation rates and our RT model it was studied the evolution of theaverage size of bubbles as a function of irradiation time and for temperatures ranging from350ºC to 500ºC, which are relevant for DEMO. On one hand, our model does not predict anysynergistic effect between H and He for temperatures lower than 400ºC (see [RT_HE-H] ). Onthe other hand, simulations evidence that for temperatures higher than 400ºC, some effects areexpected, leading to larger bubbles in the case where both H and He evolve simultaneously.Thus, according to our model, some synergistic effects could appear in fusion conditions, for agiven range of temperatures and therefore it will be investigated during next year.4.2.1.3 EXPERIMENTS FOR MODELLING VALIDATION: HE DESORPTION IN FE ANDOTHER MODEL MATERIALSDuring 2012 the work was focused in the effects of dislocations in the permeation of Hin pure iron, to compare and validate results obtained with Rate Theory at CIEMAT. Threesamples with a 50% of cold rolling were prepared at CIEMAT and measured at UPV (Univ. PaisVasco). To compare with pure Fe without treatments, an initial set of measurements were donein the same conditions (from 500ºC to RT). The others were measured in ascendingtemperature, to conserve the dislocation structure. As expected, differences were observedbetween the two methods. After analysis of all the curves, values of H permeability anddiffusivity were obtained. For the high to low temperature scheme, permeability values arefound similar to annealed iron ones.For ascending ramp, permeability and activation energy were a bit higher than duringthe subsequent cooling ramp giving more differences at low temperatures (near RT).Concerning TDHS (Thermal Desorption of He Spectroscopy, the experimental setup stillpresented some problems. The major ones were the integrity of the thermocouple and to assurethe perfect contact with the sample during the whole ramp.Asociación Euratom – CIEMAT .- Annual Report 2012 74

After some changes the comparison between annealed pure iron and cold rolled (50%)was measured for He desorption at UPV after implantation at CIEMAT. Observed peaks presentdifferences, as expected, but results need careful analysis.4.2.1.4 EXPERIMENTS FOR MODELLING VALIDATION: RESISTIVITY MEASUREMENTSAfter previous year were important effort were done to improve the set-up concerningResistivity, just few changes have been done, mainly in the measurement method. The lastexperimental change was the adaptation of an insulating-coated copper piece (for sample subholder).These changes have allowed us to obtain more reliable measurements in pure Fe andFeCrx alloys. For example, good reproducibility has been obtained for Fe5%Cr sample(experiments irradiating with 5 MeV H + ) and allow us to start analysis of results with confidence.These results were commented in EFDA monitoring meetings in MAT-REMEV WPframework (WP12-MAT-01-IREMEV-02-04/CIEMAT) by R. Vila4.2.2 MODELLING OF INSULATOR AND FUNCTIONAL MATERIALS4.2.2.1 H IN DIAMONDIn this task the main goals are the characterization of H in diamond lattice and itsinteraction with native defects, normally created during irradiation in a fusion device. The workinitiated in 2011 in relation to a systematic study of cascades generated by pka’s of severalenergies has been continued using the Molecular Dynamics (MD) code LAAMPS. This will allowto calculate very important parameters of radiation damage like the estimated number ofinterstitial-vacancies (I-V) pairs, the clustered portion of each one and the short term evolution(ps range). This last parameter very useful to compare with results obtained using otherradiation damage codes based on simple approximations as SRIM and MARLOWE but muchfaster in computation time. In the later, an important parameter to adjust is the capture radiusthat considers that a pair interstitial-vacancy at a distance shorter than this value recombines.Comparing to the more exact values of surviving I-V pairs obtained by MD, the value of thisradius can be adjusted and therefore one can calculate damage in larger dimensions and longertimes. However this process is quite time consuming because as the pka energy increases, thediamond box size has to be increased due to larger displacements and consequently calculationtime increases rapidly. Analysis also needs a lot of time. Furthermore, due to the intrinsicstatistical nature of collisions, several runs have to be made to obtain some statistically relevantresults, and the results obtained have needed more runs than previously estimated. This work isdone on collaboration with a partial-time PhD student.4.2.3 PLASMA WALL MATERIALS MODELLING4.2.3.1 RATE THEORY MODELLING OF DEFECT EVOLUTION IN IRRADIATED W(a)Model for the evolution of point defectsAsociación Euratom – CIEMAT .- Annual Report 2012 75

It was implemented a Rate Theory model that accounts for the agglomeration of selfinterstitialatoms (SIA) into In clusters and of vacancies into vacancy clusters. Their mutualrecombination is also taken into account. The model also takes into account the diffusion andgradient of mobile species (SIA and V) towards the surface.In order to calculate the dissociation frequency of In and Vp clusters, we first calculatedthe binding energies of clusters I2 - I10 and of V2 - V10 by means of Molecular Dynamics. Todo so, the potential from P. Derlet et al was implemented into LAMMPS code. By fitting theformation energy of these clusters with a capillar law we were able to extract the correspondingsurface energy, which was found to be in good agreement with results found in the literature.The 1D migration of the SIA ( according to MD and ab initio) was taken intoaccount by using a different recombination rate with vacancies, instead of the classical rategiven by 4piRD. The proper recombination rate corresponding to a 1D migration was found inthe work of A. V. Barashev et al.4.2.3.2 MODELLING OF NEUTRON IRRADIATION EFFECTS ON WA methodology to calculate the damage generated in W for DEMO due to the combinedeffects of fusion neutrons and Primary Knock-On Atoms (PKA) spectrum was developed. Thismethodology consists in a combination of Nuclear Data Libraries Processing, Neutronictransport and Monte Carlo Binary Collision codes. This methodology allows us to calculateseveral damage parameters such as the PKA spectrum, database of displacement cascades,the Damage profile, the damage function and dpa in materials under neutron irradiation.First, the neutron spectrum in the desired area is obtained by means of neutrontransport codes (MCNPX). The neutron spectra for different areas corresponding to 4000MWDEMO HCLL were considered. Four locations of an inboard blanket were selected: from andback of the First Wall [FW1 and FW2] and middle and back of the Breeder Zone [BZ1 and BZ2].The neutron spectrum and the nuclear data libraries (FENDL 3.0) were used as input forNuclear Data Libraries Processing code (NJOY) to obtain the corresponding PKA spectrum inW. To calculate the fraction of Frenkel pairs generated by PKA with energy T, Nd(T), theMARLOWE code was used. MARLOWE is a displacement damage simulations code based onthe Binary Collision Approximation (BCA). MARLOWE was modified and extended during thistask to account for the slowing down of W ions at high energies (> 25 keV/amu). The bindingenergies used to calculate the displacement of W atoms in this study are those commonlyaccepted in the literature. The calculation of damage, i.e. of stable Frenkel pairs, was achievedconsidering a recombination radius of 1.20 lattice parameters between interstitials andvacancies, as it has been found in previous studies. The damage produced by PKAs rangingfrom 100 eV up to 5 MeV were calculated in W during this task, generating a database that wasused to calculate the damage due to neutron spectra. Simulations show that on average,energy of approximately 100 eV is enough for W to create 1 stable FP. It can be noted that thisdatabase can also be used in kinetic models to predict the long-term evolution of defects.Asociación Euratom – CIEMAT .- Annual Report 2012 76

The PKA spectrum for the different isotopes of Tungsten was calculated using theNuclear Data Libraries FENDL 3.0. We found that for the neutron spectra calculated for thedifferent DEMO zones, the maximum initial energy of W PKA is 0.4 MeV. The damage functionand dpa values for tungsten at the divertor and at several blanket locations of the DEMO DCLLwere calculated in order to compare the damage production in different irradiation areas.Depending on the area of the divertor studied we found that the damage function changesconsiderably. Regarding neutron irradiation, the dose damage experimented by the tungstencomponents is similar or lower than that observed in the middle of the BZ of DEMO.4.2.4 RADIATION EFFECTS CODE IMPROVEMENT AND DEVELOPMENT4.2.4.1 METHODOLOGY FOR PKA EVALUATIONA methodology was developed to calculate the damage due to fusion neutrons inMaterials (monocristal, polycristal and amorphous systems). This methodology is based on themethodology developed by KIT laboratory. It consists of a combination of Nuclear Data LibrariesProcessing, Neutronic Transport and Monte Carlo Binary Collision codes.First, the neutron spectrum for the desired area is obtained using the neutron transportcodes (MCNP5 code). This neutron spectrum and the nuclear data libraries (FENDL 3.0) areused as input for the Nuclear Data Libraries Processing code (NJOY) to obtain the PKAspectrum. The recoil matrices are obtained using the module GROUPR of NJOY code. TheNuclear Data libraries used to obtain the recoils matrices are FENDL-3/SLIB release 2. Then,the recoil matrices are weighted by neutron spectra to get an averaged PKA energy spectrumfor each facility and irradiation spot under consideration. The PKA differential cross sectionsweighted with neutron spectrum defines the Kinetic energy distribution of the PKAs induced bya specific neutron spectrum, that is, the PKA spectrum describes how the damage is actuallyproduced during irradiation, since it defines the probabilities to generate each PKA with aspecific kinetic energy. Afterwards, to evaluate the fraction of Frenkel pairs generated by PKAwith energy T, N d (T), Marlowe code is used. Marlowe is a displacement damage simulationscode based on the Binary Collision Approximation (BCA)This Methodology allows designing irradiation experiments with ions to emulate neutronfusion effects in materials. It is possible because the displacements damage generation havebeen calculated using the same methodology for both neutron and ion irradiations (starting fromPKA spectra) [PKA_1], [PKA_2] and [PKA_3].4.2.4.2 TOOLS FOR MCNP AND CAD INTERFACINGMCAM software was used to simplify the iteration process that was required to achievethe optimal design configuration of the reactor DCLL model developed in the frame of theprogramme Consolider TECNO_FUS. Coupled use of CATIA and MCAM tool, provides thecapability to produce geometric models suitable for neutronics calculations, starting fromcomplex 3D CAD models.Asociación Euratom – CIEMAT .- Annual Report 2012 77

Original CATIA designs have been adapted by eliminating unnecessary details for thesimulation of radiation transport and then converted to MCNP geometry specifications. Acomprehensive procedure from an Excel/CATIA interface to MCNP model via MCAM has beenimplemented in CIEMAT for parametric analysis. In our procedure, spline based surfaces areconverted by approximating curves by polygons with a given tolerance and, consequently,revolution surfaces by a set of truncated cones. The resulting geometrical models are convertedto MCNP geometry description through MCAM, in terms of cells bounded by planes, quadrics(both degenerate and non-degenerate) and elliptical tori.An assessment of the capabilities of the MCAM interface (also with respect to theMcCAD tool) has been performed during 2012 in the frame of the EFDA WP12-DTM04-T12task WP12-DTM04-T12: Evaluation and development of tools to import CAD data into Monte-Carlo codes (EFDA_D_2D4AJN), in which it was demonstrated the high reliability and viabilityof this conversion tool for fusion applications.4.2.4.3 DEVELOPMENT OF COUPLED RADIATION TRANSPORT AND ACTIVATIONCALCULATIONSThis investigation was kick-started under the framework of task WP12-DTM04-T13 inEFDA’s PPPT programme. The objectives of the task were:•to review the methodologies and tools for SDR coupling available in Europe;•to produce a computational inter-comparison of these tools in a DEMO-relevantproblem, including specification, coordination and analysis of the problem, calculations andresults;•to conceptually design and evaluate methods for the estimation of uncertainties inSDR calculations, and in particular for the propagation of uncertainties in the R2S method.The first two objectives were covered by deliverable WP12-DTM04-T13-D15a, and thelast one by deliverable WP12-DTM04-T13-D15b. The task should also aim at identifyingstrengths and shortcomings, and to producing recommendations on future work and allocationof resources in a strategic fashion.4.3 TECHNIQUES FOR CONTROLLING TRITIUM INVENTORY4.3.1 TRITIUM MODELLING4.3.1.1 TOOLS DEVELOPMENT FOR TRITIUM PLANT MODELLINGOne of the scopes of the work is the strict control of dynamic and global inventory of thetritium as required by ITER, in particular in the Test Blanket Module (TBM) and the requiredauxiliary systems. That control will affect the operational availability, the operating modes of thefacility and the design of some of its units and systems. Identify the main parameters affects toa scale-up to DEMO is mandatory.Asociación Euratom – CIEMAT .- Annual Report 2012 78

Having a simulator model is thus fundamental to determining the Tritium transferphenomena and also the tritium inventory in the different units. This is the first step in the pathto obtain a model for the whole tritium plant.One of the main goals is the accurate determination of the amount of tritium per unittime that can be collected, accounted for and routed out of the TBS auxiliary systems to thetritium systems of the ITER Tritium Plant.ECOSIMPRO®, born in the frame of aerospace ESA Program is QA certified for diverseother fields, is developed by EEAA. It has been selected as the simulation software fordeveloping the breeding blankets and ancillary systems dynamic model. The Tritium amount iscalculated by mathematical models able to determine the different Tritium flows through blanketand ancillary systems. All the models developed in EcosimPro are based on the basic principlesthat govern the diffusion, solubilisation, dissociation phenomena (differential, algebraic andpartial differential equations, discrete events…)The study is accomplished through a parametric study under different operativeconditions of the blankets ancillary systems due to the different irradiation scenarios, differentBlankets size and material.4.3.1.2 LIBRETTO IRRADIATION MODELLINGLIBRETTO-4/1, 4/2 and 5 are three in-pile experiments in the temperature range ofEuropean HCLL TBM mock-ups for ITER, 300-550ºC. A global analysis on tritium flow-rate dataduring the 28 month HFR irradiation campaigns has been carried out. Further detailed analysisof tritium breeding and extraction from lead-lithium eutectic, coupled with permeation through316L (or 321 in case of Libretto-5) austenitic steels and permeation through EUROFER97ferritic martensitic steel, is being analyzed through modelling with a reference tritium transportpredictive tool such as TMAP7. Some inconsistencies on simulation results due to thecomplexity of the model and the tool limitations show the necessity of a review in depth of thepresent model. ECOSIMPRO© tritium transport library has proved a high reliability, and thus theconstruction of a new LIBRETTO model for reactor stationary regimes and temperature andhydrogen purge gas concentration transients on this tool has been proposed.4.3.1.3 DEVELOPING OF A FACILITY FOR THE VALIDATION OF A PERMEATOR AGAINSTVACUUMTritium recovery in fusion reactors is one of the main goals in R&D, as a limitedinventory is available and its production is uneconomic. That is the reason why an efficientsystem is indispensable to be developed to allow this self-sufficiency by means of a compactpermeator against vacuum.In this sense, a PbLi loop facility has been developed, in coordination with SENERIngenieria y Sistemas, in order to test and demonstrate that an in-pipe integrated solution ispossible with efficient rates greater than the current baselines considered for ITER.Asociación Euratom – CIEMAT .- Annual Report 2012 79

In this PbLi loop, different testing experiments will be carried out to measure permeatorefficiency, as well as the permeation properties of the material considered for the permeator.The experimental plan for the permeator in the PbLi loop includes permeation testingconsidering a gas mixture of hydrogen and argon and also considering PbLi circulation in theloop.4.3.1.4 DESIGN AND MANUFACTURE OF A VACUUM-PERMEATOR PROTOTYPEThe permeator against vacuum that will be tested in the PbLi loop mentioned above hasbeen designed and prototyped accordingly to a series of key features that make it an optimizedsolution for high permeation efficiency. The geometry of the perpeator has been assessed toachieve a high surface contact with the flowing PbLi, an adequate structural resistance, aminimum membrane thickness for an enhanced permeation flow, and a convenient crosssectionshape that makes it easily integrable in a pipe system, with a minimum pressure dropand the minimum connections for gas extraction.In addition, the permeator has been manufactured with a novel technique, SelectiveLaser Melting, which is capable of reproducing complex 3D geometries at a reasonable cost.This technique is similar to other metal sintering methods, but has the key advantage that noadditives are required and also that the resulting material is very compact, with no porosity anda good microstructure.A number of vacuum tests on the permeator to quantify possible leakages and to set upand analyze the capability to generate vacuum inside the permeator have been performed withsatisfying results.4.4 DEVELOPMENT OF HT SUPERCONDUCTORS FOR DEMO4.4.1 ASSESSMENT FOR RE-123 FUSION CABLE JOINTSIn the frame of the EFDA Design Assessment Studies (DAS) task devoted to thedevelopment High Temperature Superconducting technologies for Fusion applications IRECand ICMAB-CSIC, in collaboration with ENEA, have performed the mechanical assessment ofHTS tapes joints for high magnetic field applications by developing the following activities• Mechanical behavior of HTS 2G tapes and assessment of the measurement systems• Mechanical behavior of the joints developed by ENEA• Mechanical behavior of joints under magnetic fieldTests have been done on jointed samples prepared and electrically characterized atENEA by using Hastelloy supported YBCO thin films of reference SCS4050 produced bySuperPower. Mechanical and electrical characterizations of single samples (without joints) andENEA manufactured joints were performed at room temperature and 77 KMechanical properties of the tested samples meet well those reported by themanufacturer. The critical current is in the range of 100 A, and the mechanical strain for 5% ofAsociación Euratom – CIEMAT .- Annual Report 2012 80

decay in the range of 0.36%, with a stress in the range of 600 MPa. Resistance of the joints donot showed observable changes by applying mechanical stress, maintaining its initial values.Fatigue induced breaking of tapes at 77K is obtained at nearly 2x105 cycles for stressamplitudes in the range of 0.5 0.2Magnetic measurements up to 1T at 77K show a diminishing of the critical current asexpected but mechanical load induces enhancement of the critical current for each magneticfield. The enhancement can achieve more than a 10%Experiments are still running for determining superconducting fatigue limits at workingtemperature. Measurement of magnetic effect over the joints was performed by including themeasurement system between the poles of a magnet achieving a magnetic flux density of 1T.Measures of the critical current at several mechanical loads and Magnetic Flux densities werealso performed.A new system for the measurement of the critical current at several mechanical loadand applied magnetic fields up to 9T (and extensible to 14T) has been manufactured. Testingfor temperatures in the range of 20K or lower will be performed in the coming future.4.5 FUSION SAFETY ISSUES4.5.1 NEUTRONICS4.5.1.1 RADIATION AND DOSE MAPPING EVALUATION OF DEMO OF BLANKETACTIVATIONThe analyses have been conducted on the basis of a provisional HCLL DEMO1 model.The aim is to predict the shutdown dose rates at relevant after shutdown times in key locationswhere remote handling equipment is expected to operate. Dose rates at in-vessel locations andat ports exits have been calculated for a considerable number of materials used in RHequipment.In computing the dose rate mapping the Rigorous two-step (R2S) code couplingmethodology implemented in the UNED system is used to perform activation calculations onmeshes superimposed to the real geometry and to determine the gamma dose field resultingfrom neutron activation. All components of the reactor geometry has been considered in thisstudy taking account of different anticipated life-times for in-vessel equipment (1.57 FPY) andtokomak components (6 FPY). In addition, for tokamak components (VV and TFC) acommercial power plant scenario has been analyzed (20 FPY).4.5.1.2 NEUTRONIC STUDY TO SHIELD THE UPPER VERTICAL PORT OF DEMONeutron transport calculations were performed using the MCNP model of HCLL DEMOdeveloped in EFDA task WP12-DTM-04-T02, July 10, 2012, with the objective to shield theAsociación Euratom – CIEMAT .- Annual Report 2012 81

upper vertical port. These calculations were planned, since in this area, the neutron radiationlevel is critical and additional shielding might be necessary.The proposal of this task was to assess the effect of an extension of the upper breederblankets on the neutron loads in the upper port. Solid shielding blocks have been placed overthe upper breeder blankets. In addition, to optimize the neutron shielding, on the one hand, twodifferent thickness (0.2m and 0.5 m) of the shielding blocks was tested and on the other hand,three different materials as material shielding were evaluated (Graphite, B 4 C and StainlessSteel-Borated (2%) 60% + H 2 O 40%).Neutron fluence rate maps were calculated in the upper vertical port area for differentshielding options proposed in this report in order to optimize irradiation conditions for theblanket He cooling pipes in the upper vertical port.The results show significant changes in the neutron fluence rate using a neutronshielding. It decreases up to two orders of magnitude depending on the evaluated area:•The fluence rate decreases by ~one order of magnitude with a 0.2 m thick shielding.•The fluence rate decreases by ~another order of magnitude with a 0.5 m thickshielding.The shielding shape provides the best neutron shielding, of all the cases studied in thistask, since the whole upper vertical port area is better shielded.In addition, the best results were found using material 3 as shielding material, i.e. usingStainless Steel borated 2% (ASTM-A887-89) to 60% plus H2O to 40% (MCNP model: materialm13). To confirm this statement the percentage map of the original neutron fluence rate notabsorbed by the shielding is shown in figure 7 of the Report for TA WP12-DTM-04 –T10 D2:Neutronic study to shield the upper vertical port of DEMO for Graphite a), B 4 C b) and StainlessSteel borated 2% (ASTM-A887-89) to 60% plus H2O to 40% c) shielding materials.4.5.1.3 EVALUATION OF RADIATION LOAD AT TF COILSThe objective of the task WP12-DTM04-T05 is to estimate the effect of the gap size onTF-Coil radiation loads for the DEMO1 (HCLL). This effect has been estimated for 20, 10 and 5mm gap sizes and compared with the limits reported in task 03. The physical quantities ofinterest are the neutron fluence (integral and fast) and the nuclear heating due to neutrons andphotons. Calculations have been performed for an average neutron wall loading around 1.2MW/m2 and 5 FPY of continuous irradiation (causing ~70 dpa in steel of the FW).The results obtained showed that the criteria are met with at least one order ofmagnitude of margin for all the radiation loads and all the gap sizes. The effect of the gap size isaround a 30 % decrease for neutron fluence and a 50 % for nuclear heating when comparingthe best (5 mm) to worst (20 mm) case results.4.5.1.4 EVALUATION OF BLANKET ACTIVATIONAsociación Euratom – CIEMAT .- Annual Report 2012 82

This work is an activation analysis of the blanket of the DEMO model established for theWP12-DTM04 task (WP12-DTM04-T02: Description of the provisional DEMO1 MCNP model,EFDA_D_2L6X4U).An irradiation scenario and detailed material compositions are set here for the wholeWP12-DTM04 task. With these input parameters and the defined geometry and neutron source,an activation analysis has been performed for two irradiation scenarios up to a life of 5 fpy. Theactivation analysis produced independent results of residual decay heat for blanket componentcells, with isotope contributions adding up to global values.A comparative analysis has been performed between the main European inventorycodes ACAB and FISPACT, which are fully applicable to the problem. The results show goodagreement between the different codes.4.5.1.5 NEUTRONIC AND ACTIVATION ASSESSMENTS OF A DCLL DEMO MODELThe neutronic analysis of a detailed DCLL model, based on the specification of the EUPPCS model C has been implemented. Exhaustive calculations were performed in the past[NTR_1] in order to optimize a simplified model (fig. 1a) in terms of tritium breeding capability,nuclear heating distribution across blanket, shield, and vacuum vessel, helium production anddpa in the structural components of the reactor.During 2012, the final optimized simplified 3D model has been used as reference modelfor the improvement of the detailed initial 3D model (fig. 1b) in which it was needed determinewhat influence has, on the above mentioned neutronic parameters, the presence of a detaileddivertor, the blankets structures (fig. 1c), the chimney of the vacuum vessel and the asymmetryof the vacuum vessel as well. In order to achieve the better capabilities of the model in terms ofTBR, power deposition in TF coil, power amplification and helium production in structuralmaterial, the model has been iteratively modified using a CATIA macro that links the CADmodels with the MCAM interface code for the MCNP simulation of the radiation transport. Thefinal optimized 3D detailed model fulfils the fundamental neutronic requirements that guaranteethe viability of the developed DEMO model. The task has been conceived within the SpanishBreeding Blanket Technology Programme: TECNO_FUS.Furthermore, considering that the production of tritium and activation products of LiPbmight be a concern from the radiological safety point of view, an accidental release inatmosphere of radionuclides from LiPb breeder of the DCLL model has been studied [NTR_2].Activation calculations have been performed with ACAB code assuming an irradiation scenarioof 5 FPY for the maximum neutron fluence rate in the equatorial breeding zone. The results interms of specific activity, surface gamma dose rate and committed effective dose (CED) due toinhalation at different times have been used to chose the potentially more hazardousradionuclides. Dispersion of the selected radionuclides has been modeled with HOTSPOT codeusing the Gaussian plume model and two different atmospheric conditions. Offsite dose (forexternal irradiation and inhalation) due to an accidental release of 1 kg of activated LiPb hasAsociación Euratom – CIEMAT .- Annual Report 2012 83

een calculated after 5 FPY of irradiation (shutdown) using HOTSPOT atmospheric dispersionin class D weather conditions. According to the results, fulfilling the dose requirement for noevacuation would permit to release up to 40 kg of activated LiPb, without taking into account thepossible isotopic purification and detritiation systems. This value can be compared with theactually released amount in a given accidental scenario for designing the reactor confinementbarriers and safety systems4.5.2 BALANCE OF PLANT RELATED ISSUES4.5.2.1 DEVELOPMENT OF A LIPB-SUPERCRITICAL CO2 HEAT EXCHANGERPrinted Circuit Heat Exchangers (PCHE) made up by diffusion-bonded thin plates withchemically etched channels, with semicircular cross section and zig-zag trajectories; begin to bewidely used in experimental loops and the industry. However, high pressure drops are cleardisadvantages of this kind of designs. In this work, the printed circuit has been optimized tominimize pressure drops with low penalization in the heat transfer area, by means of introducingairfoil shaped fins. The PbLi/supercritical CO 2 heat exchanger proposed in Tecno_Fus has beentaken as the case study. SiCf/SiC composites have been proposed as structural materials,considering their heat and pressure resistances at high operating temperatures, compatibilitywith lead-lithium liquid metal breeder and low tritium diffusivity and solubility. Nano-Infiltrationand Transient Eutectic-phase (NITE) technique is proposed for joining the HX plates.The airfoil shape has been optimized to obtain a minimum resistance to the flown byminimizing its drag coefficient. XFOIL code (design and viscous analysis of aircraft wings) hasbeen used. NACA-4-digits series has been assessed and NACA0010 (symmetric profile) with 0ºas angle of attack has been chosen.Numerical analyses to optimize the airfoil fins arrangement in terms of pressure dropand integrated thermal flux have been performed. Results have been compared with those froma 1D heat transfer model. The temperature profiles between the 1D HT and the CFD model arevery similar. The integrated thermal flux (648) is higher than expected in the power conversioncycle model, and the resultant pressure drops are low for both PbLi and CO 2 streams.Finally, a transport model to evaluate the permeation of tritium dissolved in the liquidmetal breeder to the secondary CO 2 has been assessed. Concentration of T in SiC and PbLi,partial pressures of T 2 in CO 2 , diffusive flux to CO 2 channel and mobile inventory in SiC havebeen obtained. The results confirm the high effectiveness of silicon carbide as tritiumpermeation barrier.4.5.2.2 ENERGY STORAGE REQUIREMENTS FOR A PULSED FUSION POWER PLANTThis task evaluates the suitability of pumped-hydro installations, hydrogen-basedenergy storage systems, flywheels and ultracapacitors for their application for grid integration ofDEMO fusion plant.Asociación Euratom – CIEMAT .- Annual Report 2012 84

Pumped-hydro installation and hydrogen-based systems have high enough energy andpower capacity to their application in DEMO. Also, they offer high power ramp rates along withlow operation and maintenance costs. In fact, also their capital costs (in terms of €/kWh) arerelatively low and are mature technology. However, pumped-hydro installations are hugelydependant on the cost of civil engineering works for construction with associated environmentalconsiderations, meant that pumped-hydro is more suited to load-following at the grid level. Inthis regard, hydrogen-based systems do not present strong geographic restrictions on theirlocation. However, their energy efficiency is lower than that of pumped-hydro installations due tothe number of energy conversions required. There is also, of course, the ever-present risk offlammability.Flywheels offer very high energy efficiency along with very high ramp power rates. Theyhave low maintenance and operation costs along with a low degree of environmental impact.They are used presently on JET in helping smooth the power requirements for the TF and PFdemands in ramp up. However, they suffer a high selfdischarge rate. They are limited by a lowenergy capacity (up to seconds at rated power or minutes at partial load). However, it is worthnoting the high modularity of the system, leading the possibility of achieving power capacities ofup to tens of megawatts.Finally, it is worth noting that ultracapacitors are very much a technology indevelopment and seem unsuitable for large scale energy storage as they have a low energycapacity combined with high self-discharge rate and very high investment costs.4.5.2.3 ELECTRICAL POWER OUTPUT REQUIREMENTS OF A FUSION POWER PLANTThis activity has been focused to review of some European Grid Codes in order tocome up with comparison and statement of range regarding ramp up and ramp down activepower values and their applicability for smoothing power output profile of Fusion power plants.Additional requirements for ancillary services have been also analysed. The analysis has beenbased on an instantaneous power output profile for a steady state 1 GW Fusion power plant(DEMO plasma scenario based) obtained with PROCESS code simulation which has beenperformed within BoP task.The conclusions of the work show that in “islanded” grids like in the case of UK, thecurrent regulations set specific limits on the ramp up and ramp down of the active power flows.In strong electrical grids, like in the case of Germany, clear and specific active power rampinglimitations are set just for renewable-based power plants to regulate their power injectionespecially under grid disturbances. The electrical grid operators may well place requirements onthe electrical power output from the reactor to the grid in terms of ramp-up and ramp-down rateswhich may also lead to the need for a buffer between the grid and the reactor.Complementary to the fulfilment of ramp-up and ramp-down requirements, there is alsoan opportunity to use storage systems for balancing and for ancillary services provision.Asociación Euratom – CIEMAT .- Annual Report 2012 85

‘Balancing’ refers to the situation after markets have closed (gate closure) in which a TSO actsto ensure that demand is equal to supply in and near real time.Therefore, for DEMO it will be necessary to fulfil the requirements set by national TSOs.From this work, it is deduced that common figures for ramp-up and ramp-down limits are in therange of 30 to 50 MW/min. It is worth noting that in some countries there is scope for agreeingmore aggressive changes with the grid operator within the grid code.is worth noting that ultracapacitors are very much a technology in development andseem unsuitable for large scale energy storage as they have a low energy capacity combinedwith high self-discharge rate and very high investment costs.4.5.2.4 ELECTRICAL POWER OUTPUT NUCLEAR FUSION SAFETY AND ENVIRONMENT:MODELING HT AND HTO TRANSPORT IN THE ATMOSPHEREDuring 2012, CIEMAT together with AEMET and the UPM have made acute modelingof environmental tritium transport forms (HT, HTO) in the atmosphere for the assessment offusion facilities dosimetric impact in accidental case (type SBO) and normal conditions. Thisstudy has been done because one of the key research issues of new coming energy era wouldbe the environmental impact of fusion facilities managing a kilogram of tritium. The potentialchange of committed dose regulatory limits together with the implementation of nuclear designprinciples (ALARA, D-i-D) for fusion facilities could strongly impact on the cost of deployment ofcoming fusion technology.It was considered different short-term releases of tritium forms (HT and HTO) to theatmosphere from an ITER-like MCF reactor located in the Mediterranean Basin. It was made anumerical model for the tritium forms dispersion and dosimetric impact of selectedenvironmental patterns both in-land and in-sea using real topography and forecast meteo databy means of the ECMWF (A.Persson et al) and FLEXPART (A. Sthol et al). Specific values ofHT/HTO ratio have been explored in different levels and examined the influence ofmeteorological conditions in the HTO behavior for first 24 hours after the release. The used toolconsists on a coupled Lagrangian ECMWF/FLEXPART model useful to follow real time releasesof tritium together with real observations of change of wind direction, wind velocity,precipitations, temperature) to provide a short-range approximation of tritium cloud behavior.Inhalation doses for given HTO/HT ratios were assessed in a representative set of cases withenvironmental conditions taken from winter 2010 and spring 2011. [SAFETY_HT-01]It was demonstrated an overestimation of the sequence of tritium concentrations in theatmosphere, close to the ITER-like MCF reactor, estimated with this model when compared withECMWF/FLEXPART results. A Gaussian mesoscale qualification tool has been used to validatethe ECMWF/FLEXPART for winter 2010/spring 2011 with a database of the HT plumes. Sinceour results cannot be compared with radiological station measurements of tritium in air, we usedthe NORMTRI (Raskob et al) Gaussian model as developed by Velarde, M. It is considered thatAsociación Euratom – CIEMAT .- Annual Report 2012 86

NORMTRI allows evaluation of tritium-in-air-plume patterns and its contribution to doses.[SAFETY_HT-02]A new complete data base of tritium concentrations was developed for the months fromNovember 2010 to March 2011, in order to validate the model of ECMWF/FLEXPART. It hasbeen defined a new set of four patterns of HT transport in air, in each case using real boundaryconditions: stationary to the North, stationary to the South, fast and very fast displacement. Thedifferences corresponding to those four early patterns (each one in assessments 1 and 2) hasbeen analyzed in terms of the tuning of safety related issues and taking into account the primaryphase of tritium modeling -from its discharge to the atmosphere, to the deposition on the ground- will affect to the complete tritium environmental pathway altering the chronic dose byabsorption, reemission and ingestion both from elemental tritium, HT and from the oxide oftritium, HTO [SAFETY_HT-03]This tool was analyzed in nominal tritium discharge operational reference and selectedincidental conditions affecting the Western Mediterranean Basin during 45 days from summer2010. From comparison with NORMTRI (Raskob et al) plumes over the same area, the realtime results have demonstrated an overestimation of the corresponding climatologicallysequence Tritium concentrations in air outputs, at several distances from the reactor. For thispurpose two tritium plume development patterns were established. The first one was following acyclonic circulation of tritium over the Mediterranean Sea and the second one was based in thetritium plume delivered inland (the Iberian Peninsula) by another stabilized circulationcorresponding to a High Pressure System. One of the important remaining activities definedwas the qualification tool. [SAFETY_HT-04].The mentioned tool products were presented confronted with Tritium concentration inair data. For this purpose a database to develop and validate ECMWF/FLEXPART tritium inboth assessments has been selected from a chronic HT release experiment. It was presentedthe comparison of HT/HTO concentrations at several heights during the first release day or 24hours. Similarities and differences of numerical and experimental air tritium concentrations allowfor further refinement in model performance, even in the presence of some “disturbed” weatherconditions, at least in the short range. Last, some wet and dry deposition products.[SAFETY_HT-04]4.6 REMOTE HANDLING AND RAMI4.6.1 RAMI DESIGN GUIDELINES FOR FUSION FACILITIES4.6.1.1 RAMI ACTIVITIES FOR DEMOThis work has been developed in the framework of EFDA Work Programme 2012, and itis included in the Design Tools and Methodologies task area. A RAMI Management Process forDEMO has been defined. A revision of the previous RAMI work in fusion field has beenperformed. The key factors influencing RAMI of a fusion device have been identified, focusingAsociación Euratom – CIEMAT .- Annual Report 2012 87

on the main differences between existing experience and a novel facility such as DEMO and afusion power plant. The role of the main “actors” (ITER, IFMIF and DEMO) in the fusionroadmap and gaps and R&D needs have also been reviewed.A RAMI process for the different phases of DEMO project has been outlined but thefocus has been in the engineering design. The main steps of iterative process with the designand the main roles involved have been defined. Also interfaces and flow of information withother activities.Finally RAMI design guidelines are outlined including general ways of improvingavailability and some collection of specific recommendations for fusion field.A deliverable summarizing this work has been produced as the Report “TA WP12-DTM02-T03 - RAMI Management Process for DEMO”.4.6.2 REMOTE HANDLING (RH)4.6.2.1 INNOVATIVE METHODS FOR PIPE FLANGE JOINING/SEPARATION BY BRAZINGAND ASSOCIATED TESTING TECHNOLOGIESThe remote maintenance system (RMS) in DEMO is particularly important within thePPPT work programme since the ITER maintenance scheme for in-vessel components is notpower plant-relevant; therefore novel maintenance concepts must be developed and validatedfor using in DEMO. This work, carried out in the framework of WP12-DAS-06-T06, follows therecommendations of WP11-DAS-RH-04 about future R&D activities for fusion power plant invesselconnections, particularly pipe connections and non-destructive testing. The activitydeveloped by CIEMAT is focused on:•A solution for a pipe connector sealed by internal brazed surfaces and the study ofthe transmutation behaviour in the brazing materials.•A proposal of a design concept of a generic flange jacket for using with a boltedquick disconnect system.•Assessment of non-destructive methods for welded joints inspection (Peltier cooledcameras, EMAT and Laser UT transducers).Thus, the assessment is structured in three parts. The first comprises a conceptualdesign of a connector by brazing. The proposal lies in a previous ex-situ permanent brazing of316-L(N)-IG/Ni-200 and in-situ brazing/debrazing cycles of Ni-200/Ni-200. The first joint is donein an external furnace with vacuum conditions, whereas induction heating is performed the insitubrazing of nickel alloy parts, using a mixture of helium and hydrogen as protectingatmosphere. This allows using a leak detector for testing the brazed joint.The second part is focused on the development of a flange jacket conceptual design fora bolted quick disconnect system. A conical flange combined with a V-shaped segmentedclamp is proposed, whereas the Helicoflex concept and V-clamp have been selected as sealingAsociación Euratom – CIEMAT .- Annual Report 2012 88

principle. The flange assembly has been designed to be remotely installed/uninstalled. A RHequipment has been designed for placing and screwing/unscrewing the segmented clamp, aswell as another tool for installing/removing the Helicoflex seal.Finally, the third part of this document contains an assessment of non-destructivemethods for welded joints inspection. Peltier cooled cameras for visual inspection have beenexplored. Cameras based in Charge Transfer Device (CTD) image sensor technology likecommercially available Charge Coupled Devices (CCD) and Active Pixel Sensors (APS) are farfrom fulfil the DEMO requirements in terms of radiation tolerance. Electromagnetic-acoustictransducers (EMAT) have been also reviewed, considering its tolerance to high temperaturesand magnetic fields. The method is considered promising, since the transducers can beradiation hardened for working in this environment. Laser ultrasonic transducers have been alsoassessed. They provide high speed inspection, but the method is expensive and there are nomuch references about its performance in high radiation environments.4.6.2.2 EVALUATION OF DOSE RATE DURING SHUTDOWN PERIODSTwo analysis of shutdown radiation dose (SDR) have been performed during 2012.Both analyses are related with DEMO fusion reactors: on one hand, the DCLL Spanish reactorsupported by CONSOLIDER project and in the other hand, the HCLL DEMO1 reactor supportedby EFDA under the work programme 2012 in the task WP12-DAS06-T03.These analyses characterize the shutdown radiation environment using the ambientdose equivalent for workers and the absorbed dose in different relevant materials for RHequipment. These issues are useful to plan the maintenance of the facility, assessing if RHoperations are needed, and are also an important input in the feasibility assessment of the RHequipment were focused in the RH applications and the absorbed dose computed includeddifferent materials relevant for RH machinery.4.6.2.3 DESIGN OF INTERFACE BETWEEN UPP AND TOOLS FOR UPP RH OPERATIONFOR ITERThe EFDA WP10-GOT RH Programme promotes RH activities for ITER in a systemengineering framework and multidisciplinary engineering system. The Programme is composedof several WP to be developed by each trainee. The WP1.2 is developed by CIEMAT and itconsists of the Conceptual Design of the RH related interface between the ITER ECH UPP andCPRHS. Concretely, the development of the gripping, bolting, welding and cutting tools andinterfaces necessary to extract/insert the upper plug remotely from the port duct.The concept of several gripping tools and their interfaces [GOT_1] were carried out,taking into account the following key ideas:•The gripping tool concepts assume only one gripping point centered at the bottom ofthe surface delimited by the flange for the UPP. The single centered connection point facilitatesAsociación Euratom – CIEMAT .- Annual Report 2012 89

turning of the UPP and reduce the jamming risk during extraction/insertion. It also makesremote connection and disconnection easier and faster.•The developed gripping tool concepts [GOT_1] allow relative turning between UPPand tractor during extraction or insertion due to tolerances between UPP skids and theirsupporting rails or due to misalignment between VV port rails and TCS ramp rails.•It’s assumed that the UPP support and guiding functions are provided by the VV portrails and TCS rails, not by the tractor/gripper. The function of the tractor/gripper is pull/push theUPP on its rail supports.The gripping tool concepts avoid force feed back. For that, auxiliary devices like shockabsorber or cardan joint have to be used.Also the pre-design of one gripping tool [GOT_2] was developed according to theprevious concepts and taking into account the kinematic and friction studies of plugextraction/insertion from/to port duct.With a maximum misalignment between TCS rails and VV port rails of 0’1 ͦ and theadditional misalignment between plug and guided rails due to the tolerance of the plug’s skids(10 mm), the designed gripping tool allows a relative “y” displacement of the plug of ± 30 mmand a relative “z” displacement of the plug of ± 5 mm regarding to the point of gripping.With the assumed friction coefficients (0’3), UPP weight (20 tn) and VV port to TCSramp rails misalignments (0’1 ͦ) and the plug’s skid tolerance, the extraction and insertion of theUPP is possible without risk of jamming applying a tractor force of 95 kN in the extraction and20 kN in the insertion.Thereby, the plug can be extracted/inserted with only one point of connection withouttransferring additional moments and forces to the RH devices and avoiding plug jamming.Asociación Euratom – CIEMAT .- Annual Report 2012 90

5 TRAINING, PUBLIC INFORMATION AND SERF5.1 TRAINING5.1.1 ERASMUS MUNDUS EDUCATIONAL ACTIVITIES (MASTER AND PHDPROGRAMMES).CIEMAT has kept its active involvement in the European Master in NuclearFusion Science and Engineering Physics (ERASMUS MUNDUS), now renowned as EuropeanDoctoral College . Several Master Thesis were done during 2012 within the framework of theERASMUS MUNDUS Master in different areas of research including:1: Turbulence and electric field measurements by reflectometry in TJ-IIAaron Hernandez-Perez (Supervisor: Teresa Estrada)2: Evaluation of Beam Emission Spectroscopy as a Diagnostic Tool for the TJ-II StellaratorKostiantyn Achkasov (Supervisor: Kieran J. McCarthy)3: Investigating the Performance of an Ion Luminescence Probe as a Multichannel Fast-IonEnergy SpectrometerOleksandra Nekhaieva (Supervisor: Bernardo Zurro)4: Optical characterization of ion implanted silicaLuis Alonso Araya-Solano (Supervisor: Piedad Martin)5.1.2 GOAL ORIENTED TRAINING:CIEMAT participates to several GOT programmes.- EUROBREED. One trainee. Finished in 2012, final report submitted and approved.- Remote Handling. One trainee at CIEMAT and another at collaborating institution UPM activeduring 2012In addition CIEMAT participates in two GOT programmes launched in 2012:- Radiation Induced Microstructural Evolution and Strengthening in high-Cr-steels (RIMES)The primary objective of the RIMES training programme is to contribute to the educationand training of specialists for development of in-vessel structural materials for DEMO and ITER.This objective will be achieved through hands-on training on activities ranging from modelling toexperiments, aimed at the understanding of the interrelation between radiation induced microstructureand hardening in high-Cr steels, with and without oxide dispersion strengthening(ODS) inclusions. CIEMAT participates with one trainee, who will be hired in 2013.- GOT-4-Diagnostic TechniquesCIEMAT would be responsible for WP 7: Neutronic studies and mechanical design andport-plug integration of the ITER plasma position reflectometer and the ITER equatorialvisible/infrared wide angle viewing system. One trainee will be hired in 2013.Asociación Euratom – CIEMAT .- Annual Report 2012 91

5.1.3 EFDA FELLOWSHIPS:CIEMAT proposed a candidate for EFDA fellowships in the 2012 call.5.1.4 TECHNOFUSION SUMMER COURSE.The course was held in July, in collaboration with UPM. It was focused on ComputerSimulation of Nuclear Fusion Systems. The course was attended by more than 20 students.5.1.5 OTHER TRAINING ACTIVITIESStaff of the Association has also participated in Fusion related sections of masterprograms, oriented to Energy (Master on Energy at the Universidad Autónoma de Madrid ) orNuclear Energy (Master on Nuclear Energy and Applications, by CIEMAT and UniversidadAutónoma de Madrid)5.2. PUBLIC INFORMATIONCIEMAT kept its practice of school visits to the TJ-II facility.participated in several forums related to energy and fusion.Also CIEMAT staff5.3. TECHNOLOGY TRANSFERThe Spanish “Fusion Technology Platform” has been the starting point of a broaderplatform oriented to the “science related industry”, which involves induetries working for largeresearch facilities in general. The new platform named “INDUCIENCIA” has started its activityand has celebrated in 2012 its first general assembly. The management of INDUCIENCIA isnow in the hands of industry and CIEMAT participates through the scientific council.5.4. SOCIOECONOMICS STUDIES FOR FUSION5.4.1 EFDA TIMES MODELThis project included three activities:- Project management- Spatio temporal residential demand model, and- Development and application of ETM dissemination strategiesCIEMAT has participated in the last activity “WP12-SER-ETM-3: Development &application of ETM dissemination strategies” Within this activity, CIEMAT has been involved intasks A2 and A5:A2. Main global scenarios analyses: comparison of results, differences between ETMand TIAM modelA5. Dissemination activity: paper for a peer review journal on topic 3 (focusing on thecompetition between fusion and renewables)Asociación Euratom – CIEMAT .- Annual Report 2012 92

CIEMAT team has participated in the overview of various global energy long termscenarios published by international organizations such as IEA, IIASA, etc. Afterwards, ETMhas been implemented and some scenarios have been run and prepared for dissemination.Besides, some runs under similar hypothesis have been done simultaneously with ETSAP-TIAM and ETM models in order to compare the results mainly focused on electricity generation.Finally, an analysis of the competition between fusion and renewable technologies in a lowcarbon global energy system will be carried on. Those tasks are included in both activities, A2and A5.References:- Analysing the role of fusion power in the future global energy system. H. Cabal, et al.2 nd European Energy Conference, 17-20 April, Maastricht, The Netherlands [ECC2012 EFDATimes Model]- Analysis of the competition between fusion and renewable technologies in a lowcarbon global electricity system. Y. Lechon et al. To be sumitted to Energy Policy5.4.2 PUBLIC PERCEPTION OF FUSION RESEARCH5.4.2.1 PUBLIC DISCOURSE ABOUT NUCLEAR ENERGY BEFORE AND AFTERFUKUSHIMA ACCIDENT (WP12-SER-ACIF-1)This activity was aimed at researching the effects of the Fukushima accident in themedia coverage and presentation of nuclear fusion and nuclear fission. To this end, a specificresearch design aimed at gathering data from various samples of media articles in threeEuropean countries (Spain, Portugal, and Germany) and the international press was developedand implemented. This research design allowed a quantitative and qualitative analysis of thepublic discourse in various dimensions: thematic content, prevalence of Fukushima content onthe articles, images on fusion energy, actors involved, general valuation towards fusion andfission, and the evolution of media presentation after Fukushima.The contribution of CIEMAT focussed on the research design as well as on thecollection, analysis and reporting of the data generated from the Spanish sample. First, samplesof articles covering fusion energy were gathered using online databases. Second, a protocol forgathering quantitative data was implemented. Third, a protocol for gathering qualitative datawas implemented on a strategic subsample of articles. Finally, a report covering all the researchprocess in this activity was prepared and sent to EFDA in December 2012.Asociación Euratom – CIEMAT .- Annual Report 2012 93

6 OTHER ACTIVITIES CONTRIBUTING TO THE EURATOM FUSIONPROGRAMME6.1 ACTIVITIES RELATED TO THE BROADER APPROACH6.1 1 IFMIF/EVEDA PROJECT6.1.1.1 INTRODUCTIONThe IFMIF-EVEDA Project is composed of several subprojects, one of them devoted tothe engineering design of IFMIF and several others for the construction and test of thosesystems or components which show major risks due to their complexity and lack of previousexperience in the field. The association Euratom-CIEMAT participates actively in the firstsubproject and in the subproject LIPAc (Linear IFMIF Prototype Accelerator) which aims to buildand test a protype accelerator to demonstarte the feasibility of the IFMIF accelerator system.Regarding the engineering design of IFMIF, according to the subproject schedule,CIEMAT provided in 2012 the Design Description Documents at the level of phase II for allthose systems under its responsability in the Test Facility and in the Accelerator Facility. Theresponsibility of CIEMAT includes also several transversal activities as: the coordination of thewhole subproject at European level; the coordination of the RAMIA activities at plant level aswell as in he Test Facilities and in the Accelerator Facility; the integration of the AcceleratorFacility (shared with CEA); and Safety in the Accelerator Facility.Regarding the LIPAc subproject, CIEMAT as responsible of several systems, during2012 completed the engineering design of all of them with the exception of some details in theinterfaces with other systems or with the building and conventional facilities. Several prototypeswere also constructed6.1.1.2 ACCELERATOR FACILITIES: RF SYSTEMThe main aim of the Radiofrequency Power System (RF Power System) is to providethe required RF power to the LIPAc (Linear IFMIF Prototype Accelerator), which will be installedin Rokkasho, Japan. Through its design, manufacturing and operation, the second aim is tovalidate its concept to be applied for the future IFMIF accelerator.During 2012 many components of the RF Power System have been manufactured andsome of them have also been tested. The following paragraphs summarize the progress on thedifferent components:RF prototype Module: The prototype platform including all the mechanical and coolingcomponents was completed in May. The power amplifies and the circulator have beenassembled and aligned. The manufacturing and assembly of the Tetrodes Protection Systemwas completed after the summer. Except the PLC and the LLRF, all the different equipment tobe located in the two racks have been integrated and connected. Many tests were carried out inAsociación Euratom – CIEMAT .- Annual Report 2012 94

order to check the protection system, the electrical & RF connections and to ensure the coolingrequirements. The tests with RF power are foreseen by the beginning of 2013.An Integration Facility has been prepared for the assembling and testing of the RFPrototype Module and the rest of the RF Modules. The civil works finished at mid year and thefacility was completely ready in November.250kW Circulator: The manufacturing of the first 250kW circulator was completedduring the first half of 2012. The factory acceptance tests were successfully passed in July.The LLRF capabilities have been extended to manage the beam loading issue. TheLLRF current design is capable of modifying the output frequency through the internal mixingcircuits without the need to change the Master Oscillator output frequency. The first two LLRFunits have been assembled and tested at CIEMAT. The status of the EPICS-LLRFcommunication allows the complete integration and tests of the LLRF in the RF prototypemodule.The technical specifications for the manufacturing of the rest HVPS required for LIPAc,were prepared during the first half of the year. Another technical specifications for themanufacturing of two 16 kW Solid State Power amplifiers (SSPA) for the LIPAc Buncher cavitieswere also prepared during the first semester of the year. The acquisition process of bothcontracts began in September.A High Voltage Power Supply (HVPS) was required for the high power test of differentaccelerator components in Madrid. This HVPS was manufactured and successfully tested atfactory in August. Another HVPS (400kW, 13kV) which fulfils all the requirements from theproject and from the site conditions (Rokkasho, Japan), was also manufactured in 2012. Part ofthis HVPS acceptance tests were carried out at the end of the year and the rest are foreseen forthe beginning of 2013.The manufacturing of a test bench required for the conditioning of the SRF Linaccouplers began in September. This test bench includes a test box required for the transmissionof 200kW RF power from one coupler to the other one. It also includes the vacuum system, ashort-circuit and all the controllers and measurements. The complete test bench will be ready inMarch 2013.6.1.1.3 ACCELERATOR FACILITIES: BEAM DUMP & HEBTThe effort has been concentrated on finishing the detailed design of these systems andstarting the preparation of the technical specifications for the procurement of the maincomponents. The HEBT line and Beam Dump Engineering Design Report has been delivered(LIPAc HEBT Line and Beam Dump Engineering Design report. Loaded on IFMIF DMS:https://users.jt60sa.org/?uid=22PCYC)(a) HEBT Line:Asociación Euratom – CIEMAT .- Annual Report 2012 95

- The layout and position of the beam dump cell wall after the last changes in theaccelerator design has been finally decided and agreed. A detailed proposal of the interfacebetween this wall and the beam tube has been made and agreed among all involved parties.Radioprotection calculations have been performed to validate this design including the gaps thatmust exist between the different pieces. The radiation shutter design has been optimized bychanging its shape to a troncoconical one with diameters 300 mm and 420 mm.- The different pieces necessary for the beam dump to HEBT connection have beenprocured: bellow, flanges, joints and articulated collar. This system will allow the remotedisconnection of the cartridge. The contraction of a hydroformed bellow was checked reachingplastic deformation. Therefore a different edge welded bellow will be considered.(b) Beam Dump:- A commercial ionization chamber adequate for the beam dump needs has beenchosen, CRGE10 by PHOTONIS. Its sensitivity to gammas is 4.5 x 10 -11 A/(Gy/h). In parallel asecond chamber has been designed and three prototypes have been manufactured and will betested soon.- A method to check the cartridge alignment without removing the local shield has beenworked out. It is based on the positioning of one point using fiducials on the pipes emergingfrom the shielding and complementing this information with the rotation of the cartridge as arigid body, using clinometers.- The detailed design of the local shield is now almost finished and prepared for itsprocurement. Almost all the details are now defined. New radioprotection calculations havebeen performed to define and validate the detailed design including penetrations and gapsbetween pieces. The last improvements performed are the following:The rear water tank has been substituted by a 30 cm poliethylene disk. This disktogether with the rear iron disk has been arranged in two trolleys than can be displaced laterally,using the same design as that of the frontal part of the shield. In this way the installation andmaintenance procedures are easier and the risk of damaging the cartridge during theseoperations disappears.Insertion of a metallic profile to support the water tank and ease the cartridge alignment.- The cooling water purification system is now designed. Results from TRACT codeindicate that copper corrosion of the cartridge is expected at a level lower than 3 mg/m 2·day andconfirm therefore that the designed purification system has been conservatively overdimensioned.- The hydraulic tests of the cartridge prototype have shown that the response of thesystem to flow induced vibrations is extremely small, being the measured acceleration valueslower than 0.1g.Asociación Euratom – CIEMAT .- Annual Report 2012 96

- The manufacturing of the final flange for the cartridge has finished. Last acceptancetests are on-going. Vacuum leaktightness and final dimensional and geometrical checking arethe last step before it is sent to CIEMAT facilities.6.1.1.4 ACCELERATOR FACILITIES: DIAGNOSTICSDuring 2012, a detailed design review (DDR) with a panel of international experts in theaccelerator beam diagnostics field was organized by CIEMAT. The revision was held 19th-20thJune 2012 at CIEMAT-Madrid and provided the necessary feedback to the diagnostics designsbefore starting the manufacturing phase [BI_1]. The detailed design of FPMs was finished at theend of 2012 and the DAQs validated. The spatial resolution of the FPMs in the diagnostic platewas doubled by including a second PMT. The design of the FPM at the end of the HEBTincluded a viewport DN100 holder instead of DN63.Detailed thermo-mechanical simulations were performed to validate the design of theLIPAc interceptive slits for emittance measurements. A study of the impact of differentparameters (e.g. plates angle, material, plates thickness…) to find a solution for the high powerdeposition that LIPAc slits have to withstand (1.125 MW beam). A design including graphiteplates for RFQ commissioning, and TZM alloy plates for the SRF commissioning (3 mm thick,15º) was chosen [BI_1]. A prototype of the slits (main block) was done at CIEMAT.Beam dynamics studies for the interceptive energy spread measurement was done andpresented at the DDR. It concludes the technique is valid for LIPAc in case the spatial resolutionof the interceptive profiler (SEM-grids) is increased. A Beam Instrumentation mini-workshopwith international experts was organized 5 th October 2012 by JAEA at Mito (Japan)(http://www.ifmif.org/c/index_nav_5.htm?n5/newsline_2310.htm) to discuss about such problem.As a result, a beam steerer designed and manufactured by CEA-Saclay will be used to increasethe spatial resolution.The detailed design of all the BPM’s was finished. The MEBT BPM’s were changedfrom capactive to stripline type to avoid mechanical damage due to heating in CW operation.Pre-series manufacturing of the MEBT and Diagnostics Plate pickups started. The interfacepieces for the test bench are being manufactured for such a purpose. It was decided to developan in-house acquisition electronics. The development includes a commercial digitizer, an ananalog front-end, a timing board, and an automatic calibration board. The design waspresented in the beginning of 2012 as an Invited talk in a DITANET Workshop at CERN.The design of the Diagnostic plate mechanical support structure, together with thealignment supports for the instrumentation included in such diagnostic plate have beenpresented [BI_1]. Some interface problems were identified between a current transformer and aResidual gas Bunch Length Monitor after the DDR. Work on this interfaces were performed atthe end of the year and finally solved beginning 2013.The status of the beam instrumentation design was presented in an invited talk at theInternational Beam Instrumentation Workshop (IBIC’12) at Tsukuba, Japan [BI_2].Asociación Euratom – CIEMAT .- Annual Report 2012 97

6.1.1.5 ACCELERATOR FACILITIES: DTL & MS(a) Resistive magnets:The magnetic tests of the first prototype magnet were carried out in July in the Hall androtating coil test benches installed in ALBA-CELLS (Barcelona). During installation of themagnet several manufacturing problems were detected which will be solved in the next units:placement of the CCR with respect to design position and leak in a quad connection which hadto be rewelded. The magnetic measurements show a good agreement with the simulationsconcerning field harmonics and crosstalk between quadrupolar and dipolar fields. The technicalspecifications for the power supplies of the magnet are being produced. Still some questionsremained concerning the requirements in terms of transition from negative to positive orramping up of the current.(b) Buncher:The mockup of the cavity is completed. The manufacturing drawings have beenproduced and are under revision. The coupler is under design and several tests with an externalcompany (Ecor) are planned. A design of the tuner is being developed following the technicalspecifications. A 3D mockup already exists.(c) Scrapers:The manufacturing of the first unit was launched by the company AVS. The four copperblades were brazed, the cavity manufactured and all the pieces manufactured. The welding ofthe thermocouple into the column was under process in order to proceed with the assembly ofthe complete scraper in the beginning of 2013.(d) Beamlines and BPM’s:After finishing the design of the beamline, the fabrication of a BPM prototype (MBPM)was launched, together with the first vacuum line section. The type of BPM was changed fromcapactive to stripline, following the recommendations of the DDR BI review committee.(e) Vacuum system:Molflow+ was used for the new vacuum calculations. The results are very similar to theFD method but a more detailed design is needed in order to optimize the conductance of thebuncher cavity.(f) Assembly:The mechanical support was refined: e.g. the buncher support was adapted to thedimensions of the magnet support. As recommended by the experts, surfaces for alignmenttargets will be placed in the global chassis for use once the beamline is completely assembled.New feet were designed which permit the adjustment in three coordinates. The specifications ofthe welded bellows were updated to accept a bigger compresion of up to 8 mm and 0.5 mmtransversal deformation. It will mean an easier mount and maintenance of the CF flanges.Asociación Euratom – CIEMAT .- Annual Report 2012 98

A prototype support has been designed in order to test the integration of the magnets,the scraper and the vacuum chamber inside with the beam position monitor. The proto supportis prepared for 2 magnets and 1 scraper. However, in a first stage will be used with one magnetand one scraper (+ BPM chamber). The proto support will be the perfect place to test alignmentof complete suport with adjustment feet (see below) and CCR in the baseplate.(g) DTL- Solenoid package:Two main tasks have been developed during this period:The first one is the cold test of the complete set of coils. A custom support wasprepared to hold the coils against the electromagnetic forces. The test was performed in avertical cryostat at CIEMAT laboratory on Oct, 18 th 2012. The solenoids were ramped up to 240A (nominal current is 210 A) without quench. Both steerers were ramped up to 75 A withoutquench (nominal current is 50 A). With both steerers powered at 75 A, the solenoid was rampedup. A quench happened at 237.6 A. The second quench in the same conditions took place atcritical current, 263.4 A. When the solenoid was powered at 241.5 A, both steerers wereramped up and down at different rates, up to 60 A (maximum current of LIPAC power supplies),without quench. Finally, the axial magnetic field was measured at cold conditions. There is agood agreement in magnitude, but a slight disagreement in the position, likely due to differentthermal contractions of the probe support and the coil. Warm field measurements with higheraccuracy are possible, because it is a linear problem, without near ferromagnetic materials.The second task performed in this period is the preparation of a test where the coils areat horizontal position. It will be performed in a vertical cryostat. The aim is to evaluate theefficiency of the cooling, because the helium bubbles created in the solenoid aperture will havesome difficulties to migrate to the outside of the solenoid. A custom vessel has been designedand fabricated at Trinos Vacuum-Projects, in Valencia (Spain). The dummy beam pipe isvacuum-tight. The vessel will be completely immersed in a liquid helium bath, while the coils willbe powered till quench, to check the performance at horizontal position.The series production of the helium vessels for the solenoid package is being studied.The design must be compliant with the High Pressure Gas Safety Regulations in Japan. Inorder to know which criterion must be fulfilled for the calculations and the fabrication process,contacts will be made with JAEA, with the help of F4E.6.1.1.6 ACCELERATOR FACILITIES: SAFETY AND RADIOPROTECTIONSafety and Radioprotection analysis of IFMIF Accelerator Facility has been performedto justify and improve, in terms of safety, the Accelerator Facility (AF) design provided in theframe of the Engineering Design Activities of the IFMIF/EVEDA project. Although all kind ofpossible hazards is included in the Accelerator Facility Safety Report, special focus was put onAsociación Euratom – CIEMAT .- Annual Report 2012 99

protecting workers and general public against ionising radiations. For reaching these objectivesseveral milestones were achieved during this year:Safety Dimensioning covers all the main information needed for radioprotection duringthe different states of IFMIF, both, for operation and maintenance of one or both acceleratorlines. For this work development of adequate tools as MCUNED should be carried out, includingvalidation and modification of available libraries and nuclear models against experimental data[UNED0007], [UNED0011] and [UNED0025]. Interaction of deuterons up to 40 MeV withstructural materials of both accelerator lines in their different systems was studied in all thecases [UNED0011]. Also all related information on the software used for safety analysis of theimpact to the workers and the public of the installation was specified.Analysis of the radiological impact to the workers and the public was performed duringthe operation of the accelerators and in maintenance periods.Prompt doses by system was computed in the rooms adjacent to the accelerator vaults,recommending changes in materials composition of several components as scrappers,additional shielding or changes in design of conventional facilities. Preliminary studies werecarried out with original designs, pointing out those components where high energies would bereached (above 9 MeV) [RadHEBT2012], [UNED0020], [UNED0022] including proposals ofchanges which would improve the radiological conditions in the vaults and in adjacent rooms.More refined calculations, which included all proposed changes in the components or design offacilities or operations, both from radioprotection point of view and other fields, were completed[SEA38], [UNED2013]. These changes assure the achievement of required levels of protectionfor the workers, although additional improvements in the design should be accomplished in thefuture in order to reach all radioprotection requirements. Components affected by all energiesup to 40 MeV were regarded in the analyses.Residual doses by system are important in assuring than maintenance in eachaccelerator line is possible according to the required levels of availability, otherwise makingnecessary proposals which could help in achieving them. Part of these analyses also provides apreliminary input for calculations of waste production in gaseous, liquid or solid form. Onceagain preliminary calculations were performed using original designs [UNED0013],[UNED0027], [RadHEBT2012], [Dlopez2013] including changes in shielding or givingrecommendations of manipulation of components during maintenance. Handling of thosecomponents by remote systems or manually were also analyzed under these calculations,including changes in some modes of maintenance to achieve IFMIF dose objectives.Components affected by all energies of deuterons up to 40 MeV and secondary particlesproduced were regarded in the analyses.Management of solid wastes and effluent analysis in normal operation is affected byamounts produced under IFMIF conditions of operation, duration of the installation or energiesachieved by deuteron beams. Calculations showed a lower production of activation products inair than expected [UNED0022] what would change the necessities of ventilation in the vaultsAsociación Euratom – CIEMAT .- Annual Report 2012 100

while calculation of doses to more affected individuals of the public out of the installationshowed levels in normal operation below requirements. Activation products in structuralmaterials and cooling water was also analyzed, giving rise to results of residual doses and firstapproaches of waste production [UNED0021], [Dlopez2013] which indicates that 99% of solidwastes will be below clearance levels some decades after the shutdown of IFMIF. A detailedstudy by component would be desirable in next stages.Failure Mode, Effects and Criticality Analysis (FMECA) was used as a tool to analysethe case of abnormal situations in IFMIF, regarding their probability and severity of theirconsequences [TEFMECA]. This analysis was carried out in qualitative form for the AF takinginto account possible Postulated Initiating Events previously defined [TEPIEs]. As aconsequence of this study an analysis of possible safeguards, which should be included inorder to reduce the risk (function of probability and severity) of every situation below theclassification of minor, was performed. Additionally a revision of Safety Requirements in AF wascarried out taking into account the results obtained in this analysis [TESafReqRev]. In this stageonly internal events were included, however, external events and quantitative analysis shouldbe carried out in future studies.Optimization of radioprotection studies below dose objectives is achieved by usingALARA studies. Those studies will be also carried out in IFMIF by using cost-benefit analysis inall possible options.Safety Analysis Report (SAR) of IFMIF will include all safety studies carried out in theinstallation as a whole. All the studies performed within the AF, herein compiled, will thereforeform part of the Preliminary PSAR and once Engineering is completed and election of a site isconcluded a Final FSAR would include all the work previously performed.FSAR would also include written and approved operating procedures (OPs) which arepart of the safety of IFMIF. OPs should provide clear instructions for safely conducting activitiesand therefore should be maintained consistently with management QA systems. OPs willinclude descriptions of tasks to be preformed, appropriate safety controls, and where applicable,requirements for verifying initial conditions, operating conditions to be maintained, and data tobe recorded. OPs should meet national regulatory requirements, once definitive site is elected,and will be developed for the various facilities in close cooperation with design engineers,Project Team, and Project Leader within IFMIF.6.1.1.7 TEST AND TARGET ACTIVITIES: RH ENGINEERINGThe work developed during 2012 for the engineering design of the RH systems of theTest Facilities of IFMIF has been devoted to the upgrade of the design concept. The motivationhas been the evolution of the design of the components to be remotely handled along theEVEDA project and the layout of the Test Facilities.The new Test Cell concept includes some big and heavy (up to 120 tons) shieldingplugs that close the Test Cell and shield the radiation in the Access Cell. Therefore, the new RHAsociación Euratom – CIEMAT .- Annual Report 2012 101

concept still includes two cranes to be installed in the AC of IFMIF (one heavy crane plus onemast crane to support the servomanipulator) but the heavy crane has increased its loadcapacity to cope with the new components to be handled. In addition, the new size of theAccess Cell has led to modify the foreseen working area of both cranes.All these changes have been explained in the Design Description Document phase IIreports (DDD-II) among other, improvements on the definition of the system requirements, theinterfaces with other systems, RAMI and safety analysis (Safety Check list, Hazard Sources listand a Basic Safety FMECA).6.1.1.8 TEST AND TARGET ACTIVITIES: MEDIUM FLUX MODULES ENGINEERINGThe Liquid Breeder Validation Module (LBVM) is one of the medium flux test modules ofIFMIF. The objective of this module is to deal, in a versatile set up, with some of the R&D needsof the Liquid Breeder Blankets that require irradiation experiments under a relevant neutronenvironment and the expected temperature operational conditions in DEMO. The LBVM mainlyconsists on a stainless steel 316 LN container able to house 16 EUROFER capsules which arefilled with LiPb. In addition, the design of a Neutron Spectral Shifter (NSS) to be installedupstream the LBVM has been considered to optimize the irradiation conditions of the LBVMexperiments.During 2012, the first phase of the LBVM design description document has beenreported (IN-IF-TFTM-010: Design Description Document phase I of the IFMIF Liquid BreederValidation Module. Date:15.01.2012). After that, the work performed has been focused on thepreparation of the second phase of the LBVM design description document (BA_D_226M5Xv.1.2: System Design Description Document (DDD). Liquid Breeder Validation Module PBS22600. Date: 19/11/2012) and other further analysis which will be included in the followingphase [LBVM-1]. Some of these studies covers the following topics:Recalculation of the neutronic performance of the LBVM by using the library FENDL-3.Optimization of the module geometry by changing the test region to cylindricalgeometries and reducing the number of cooling lines.Implimentation of thermal-hydraulic and mechanical calculations as support of the NSSdesign.Functional analysis of the LBVM as support of the safety FMECA analysis. [LBVM-2].Significant progress in safety issues. [LBVM-3]. The safety FMECA analysis andactivation calculations of the module materials have been performed. In addition, the loss ofcoolant scenario has been assessed.Study of the degraded mode of operation to increase the availability of the module. Inaddition, a RAMI FMEA has been performed during this period.Asociación Euratom – CIEMAT .- Annual Report 2012 102

Utilization of the MCAM code to introduce the updated geometries of LBVM and NSS inthe MCNP Test Cell model.Implimentation of a rough cost estimation of the LBVM based on materialsconsumptions and required instrumentation.6.1.1.9 TEST AND TARGET ACTIVITIES: LOW FLUX MODULEThere has not been any activity related to this issue during 2012.6.4.1.10 TEST AND TARGET ACTIVITIES: START-UP MONITORING MODULEDuring 2012, CIEMAT has contributed to the engineering design activities of theSTUMM with calculations of the C-FOS sensitivity under IFMIF conditions. C-FOS is aCerenkov radiation based sensor which will be installed inside the STUMM.A C-FOS model consisting in a SiO 2 optical fiber (not realistic, since diameter is 2 mm,but important to see qualitative effects) was used to calculate the number of Compton electronsgenerated in the detector. These electrons are the responsible of the Cerenkov light which canbe partially collected by the optical fiber. Not all the produced photons will be collected to theend of the fiber. It depends on the parameter, which gives the collection efficiency and isstrongly angle-dependent.This result shows that only a 1.3% of the total Cerenkov field is collected. Thus, whenthe C-FOS is placed in the vertical direction, perpendicular to the neutrons preferential direction,a small fraction of photons will be finally collected. The best collection angles are 45º and 135º,with 90º the z-axis in the Test Cell.6.1.1.11. DESIGN INTEGRATION: SAFETYIn IFMIF-EVEDA safety approach is based on defense in depth principle to preventaccidents by a robust design according to nuclear standards and selected design justification.Following actions were carried out in 2012:Safety referential:Contribution to updated main safety supporting guides:- BA_D_22AKCA, V2.0 (05/15/2012) Guideline “IFMIF EDA hazard evaluationtechniques:Guideline was updated in coherence with FMECA methodology applied for eachfacility. Main changes are related to frequency ranking table and risk matrix index. In coherencewith new risk ranking quantitative approach (QA) was defined. Approach is applied at IFMIF-EVEDA as validation tools of safeguards considered at existing engineering desing state.- BA_D_224X48. V4.1 (01/13/2012) “Safety specifications for the Engineering DesignActivities of IFMIF”:Safety Specifications document was review and updated to be consistentwith guideline for hazard evaluation.Asociación Euratom – CIEMAT .- Annual Report 2012 103

- BA_D_22DYV9. V2.0 (01/13/2012) “IFMIF Confinement strategy”:Review ofconfinement strategy guideline was focussed on: updating and filling source term and releasepath onto engineering development and getting consistency with relating guidelines andspecifications.Safety engineering according to engineering design development:Safety dimensioning of accelerator facility (AF):- AFREQ: first approach of safety requirements report was performed focused onradiological safety functions and related service functions. Requirements were integrated aspossible on engineering design development (DDD-II). Document was used as a base to getmore complete safety requirements in the frame of IFMIF-TE contract.- BA_D_22YZZU, V1.0 “Accelerator facility safety report”: Focussed on satisfyingdefence in depth principle for the accelerator facility, safety accelerator studies considered thefour configuration states (irradiation, maintenance, start-up and shutdown) to satisfy safetycriteria for IFMI-EDA. Prompt and residual radiations were defined by neutronic calculations andresulting dose maps. It provided the base for shielding design to reach design requirements.Also, areas classification was proposed. Special effort was performed to study radiologicalconditions in those areas were penetrations were expected and in RFQ, MEBT, HEBT andbeam dump systems. Impact of materials on radiological conditions was evaluated.Safety analysis of accelerator facility and test facility (TF)- IFMIF/4NT/0275876/000/01 (April 2013) Final Doc. Tractebel AF FMECA andIFMIF/4NT/0276242/000/01 (April 2013) Final Doc. Tractebel TF FMECA: Based on guidelinefor hazards evaluation techniques and existing FMECA analysis of LBVM and functionalanalysis and preliminary FMECA, AF and TF FMECA analysis was completed to preventfailures, to detect and to mitigate consequences and to increase safety. Is was performedthrough strong interaction between safety and engineering design teams under contractbetween IFMIF and TE and technically coordinated by CIEMAT.- BA_D_XXX V1.0 (4/16/2012) Draft “AF Safety requirements” andIFMIF/4NT/0278834/000/01 Tractebel TF Safety requirements”:Safety requirements wereupdated and completed in coherence with FMECA analysis results under contract IFMIF-TEand technically coordinated by CIEMAT. SIC classification was revised.- IFMIF/4NT/0277835/000/01 (April 2013) “Tractebel Eng. Potential Initiating EventsFinal Document”:External and internal potential initiating events were identify accidentsequences to be analysed at further IFMIF phases- IIEDR Chapter 3.8 “IIEDR Safety Summary”: Integration of main safety facility report ina safety summary for IFMIT-IIEDR to point to safety approach reached and identifyingremaining issues to work with in future project phases6.1.1.12. DESIGN INTEGRATION: RAM EVALUATIONAsociación Euratom – CIEMAT .- Annual Report 2012 104

The second iterations of RAMI analysis for Accelerator Facilities (AF) and Test facilities(TF) have been completed.In the case of Accelerator Facility (AF) (BA_D_2295AZ: “Accelerator facility RAMIReportDDD-II -Analysis description and individual results for each system”. 20 nov 2012) and[RAMI_AF_SOFT], the Beam Availability (BA) is defined as the product of Beam Efficiency (BE)and Hardware Availability (HA). The BE has been estimated by on one hand, evaluation ofbeam trips based on information collected from similar facilities, and on the other hand,evaluation of beam degradation assessing the acceptable failures (fault tolerant operation) andtheir impact in the main parameters of the beam.The HA has been estimated by the detailed fault tree modelling of the different systemsof AF. The inherent availability requirement for AF has been allocated among the differentsystems and compared with the assessed value. Additional design recommendations havebeen proposed to be analysed in the final iteration.Furthermore, maintenance and logistic studies have carried out, especially for the RFsystem, including a comparison between tetrodes technology and solid state technology,highlighting the advantages related to availability and operation and total costs of the solid statetechnology [Logistics RF SOFT]Availasim software has been adapted to IFMIF in order to be able to simulate the wholeoperation and maintenance performances of IFMIF accelerator and some test have been run.Regarding TF, a new very detailed Test Cell and Test Modules FMEA has beendeveloped taking into account the significant evolution especially of the Test Cell. The influenceon availability of the design evolution has been assessed, and the implementation of RAMIstrategies [RAMI_TF_SOFT] into the design of TF(fault tolerant design, reduction of accesstimes and maintenance times, reduction of complexity, increase of reliability in criticalcomponents, design for fail-safe of modules…) has been followed.Also, the availability requirements have been allocated for the current design, and theimplication of the requirement for the different systems have been analysed.Furthermore, FMEA analysis has highlighted Human Factor as critical for the RemoteHandling system. RAMI analysis of RH has been started in order to evaluate the influence ofRH performances both on the unscheduled maintenance (influence on Mean Down Time incase of failure in TTC) and on the scheduled maintenance (influence on the time allocated forthe different foreseen tasks). In that sense, THERP (Technique for Human Error RatePrediction) method has been studied in order to merge the common RAMI approach with HRA(Human Reliability Assessment).Apart from RAMI analysis of AF and TF, CIEMAT is in charge of the coordination andintegration of the whole RAMI analysis for IFMIF. In this line, a first draft of RAMI report forIFMIF has been produced (IIEDR- Annex RAMI report) that includes other general aspects asoperation and maintenance plan, general requirements, methodology, database, etc.Asociación Euratom – CIEMAT .- Annual Report 2012 105

6.1.1.13. NEUTRONICS STUDY FOR THE INSTALLATION OF THE LBVM IN THE MEDIUMFLUX AREA OF IFMIFIFMIF will be a fusion dedicated facility producing a large amount of neutrons with theappropriate energy spectrum to test materials and subcomponents for DEMO and future FusionPower Plants.While the high flux area of IFMIF will be devoted to reduced activation structuralmaterials for first wall and blanket, the medium flux area will be dedicated to functional materialsfor breeder blankets. In particular, the Liquid Breeder Validation Module (LBVM), will hostexperiments related with functional materials for liquid breeder blankets. Since IFMIF neutronspectra have been intended to fit the most irradiated areas of a fusion reactor in the high fluxarea, the irradiation conditions in the LBVM placed in the medium flux area of IFMIF have beenassessed. The effect of some neutron shifter/reflector components to optimize the neutronspectra have been evaluated in order to find out the proper irradiation conditions for functionalmaterials for liquid breeder blankets.Therefore, the objective of this report is to summarize the neutronic calculationsdeveloped to evaluate the viability of IFMIF neutron source to perform relevant irradiationexperiments on functional materials for liquid breeder blanket concept for future nuclear fusionpower reactors (ITER, DEMO). The irradiation parameters evaluated for this purpose are: thetritium production for liquid breeder material (Pb-17Li) and the damage dose [dpa] and gasproduction to damage dose ratios for Al 2 O 3 and SiC functional materials.The main conclusion is that, it is possible to perform relevant irradiation experiments onfunctional materials for liquid breeder blanket concept for the future nuclear fusion reactorDEMO. Nevertless, the use of some shifter components will be needed to optimize someirradiation parameters [Neutronic_1].6.1.2. JT-60 SA CRYOSTAT6.1.2.1. ACTIVITIES IN THE BROADER APPROACH. THE CRYOSTAT FOR JT-60SACryostat Base (CB) manufacturingThe Cryostat Base (lower part of the whole cryostat) of the JT-60SA is a stainless steelstructure with a total weight around 240T. It consists of seven pieces, three forming the nine leglower structure, three forming a double ring supporting structure and a inner cylindrical shell forvacuum closing. The construction started in 2010 and the completion of the manufacturing hasbeen completed during the 2012. The job has been carried out by IDESA in Aviles (Asturias,Spain) with some subcontractor for machining.Welding of all of the Cryostat Base lower structure sectors has been completed by May2012. The inner cylinder was also complete even before, and welding of the double ring sectorshas been completed by August 2012.Asociación Euratom – CIEMAT .- Annual Report 2012 106

The final machining and trial assembly of the components was performed byASTURFEITO, which is well equipped with large-capacity machines and conveniently locatedvery close to IDESA and to the port of Aviles. Machining of the first lower structure sector beganin mid May 2012. Machining was performed in a number of phases for each componentaccording to the workpiece orientation required.A final surface treatment & cleaning was required to give an appropriate visualimpression and to be compatible with the cryostat vacuum. All surfaces were pickled and nonmachinedand non-vacuum surfaces were also sandblasted to give a homogenous finish. Thefinal dimensional inspection, after the preassembly operation, took place on 25-26 th October2012 in the presence of representatives from F4E, JAEA and CIEMAT. A laser tracker wasused to check the position of all the interface points such as the TF and VV supports. JAEA hadmade a number of earlier visits including with staff from Toshiba (responsible for the finalassembly) in order to prepare for the on-site assembly work.The components were packaged and ready for collection on 8 th November. Thepackaging structures, including the lifting points, were agreed previously with the transportcompany contracted by F4E, a number of improvements having already been made e.g. tolifting points to improve stability. The components were shipped, from the port of Aviles, with anumber of temporary stiffening structures still in position, in particular a star-shaped structureinside the inner cylinder to maintain its roundness.The cryostat base was transported on behalf of JAEA, at the beginning of 2013, fromthe Hitachi port to Naka over 7 nights. All components were accepted following an incominginspection.An assembly procedure was prepared by CIEMAT for JAEA, in the light of theexperience gained from the pre-assembly.Cryostat Vessel Body Cylindrical Section (CVBCS)The Cryostat Vessel Body Cylindrical Section is the part of the cryostat in the middlebetween the Cryostat Base and the Top Lid. The job carried out in this part has beenconcentrated in minor corrections on the technical specifications for the manufacturing. Thesecorrections have been raised from the experience gained in the manufacturing of the CB. It wasnot possible, due to not having the necessary budget, to start with the tendering process for themanufacturing. The call for tender will be launched during 2013.6.1.3. DEMO R&D6.1.3.1. SIC/SIC CHARACTERIZATIONDuring this year, the optical and microstructural characterization has been carried outon the 6H CVD SiC of Tankeblue. The study has been extended to gamma irradiation up to 9MGy and He and D implantations at 100 kV, RT 10 16 ion/cm 2 and 1.2 Mev, RT 10 16 ion/cm 2respectively.Asociación Euratom – CIEMAT .- Annual Report 2012 107

6H CVD-SiC of Tankeblue seems to be stable under irradiation in the testing conditionsof this work. The structure of the material is unchanged and the hexagonal cell is maintained.Nevertheless, the gamma irradiation at 5 MGy produces some changes in the vibrational modesof the Si-C bond that is observed by the displacement of the most characteristic SiC band. Thiseffect is probably related with changes on the angle Si-C.The results of the He or D implantations indicate that the 6H CVD-SiC of Tankeblue isnot damage although the optical absorption after implantation increases as consequence of thebombardment of the surface.All these results will help to improve the SiCs databases and to relate physicalproperties, such as electrical or mechanical parameters, with microstructural or structuralaspects.6.1.3.2. INSULATORS CERAMICSThe main aim of the work was to address the ionizing radiation induced absorption ofhydrogen isotopes in Al 2 O 3 . Alumina samples were deuterium loaded for different times andpressures. After being deuterium loaded the samples were mounted in a special irradiationchamber in the beam line of a Van de Graaff electron accelerator. The experimental set uppermitted one to irradiate the samples with 1.8 MeV electrons at temperatures between roomtemperature and 750 ºC and to measure the release of the previously loaded deuterium duringirradiation, as a function of temperature and dose. Thermo stimulated desorption (TSD)measurements were carried out for both electron irradiated and unirradiated samples in order toevaluate the possible radiation enhanced retention of the loaded deuterium. In additiondeuterium loading was carried out with both the sample and the surrounding deuterium gasexposed to 1.8 MeV electron irradiation in order to evaluate the radiation enhanced deuteriumabsorption.Radiation enhanced interaction between deuterium and Al 2 O 3 has been evaluated.Deuterium enhanced absorption and stabilization has been observed. TSD measurementsindicate that the temperature for release of the previously absorbed deuterium increases due tothe ionizing radiation [RAD_AL2O3]6.2. DUAL COOLANT BREEDER BLANKETS PROGRAMME6.2.1. OVERVIEW OF TECNO_FUS PROJECTTecno_Fus is a Spanish National Programme to develop a dual-coolant breedingblanket design concept and its plant auxiliary systems for a future power reactor (DEMO). Theprogramme began in 2009 and will end in 2013. The Final Report is expected in the beginningof 2014.Tecno_Fus is focused in the development of required new expertise in several fields:Neutronics for design of Fusion Technology components.Asociación Euratom – CIEMAT .- Annual Report 2012 108

Development and characterization of fusion reactor materials (EUROFER-typesteel, SiC composites, proton-conductor ceramics).Computational fluid-dynamics and Magnetohydrodynamics (MHD).Structural thermo-mechanics and electromagnetic analysis.HX)Design of advanced Plant Auxiliary Systems (permeator against vacuum, PbLi-CO 2Safety and environmental impact studies.Development of a Systems Code for reactor design.The programme follows the reference of the EU reactor Model C (1500 MWe), fromwhich it establishes the balance of plant. Thus, the reactor is divided in 12 sectors (30º/sector),each one of which includes 3 outboard blanket modules (10º/OB module) and 2 inboard blanketmodules (15º/IB module). The reactor is also segmented in 4 auxiliary systems loops.6.2.2. TECNO_FUS DCLL BREEDER BLANKET DESIGNBoth PbLi inlet and outlet are placed at the top of the module to allow remotemaintenance through the upper port. Each module is composed by 150 welded plates with innerHe channels. There are three different plate shapes to conform PbLi channels. The heliumstreams are arranged in counter-flow, whereas He is distributed through the back-plate, which isalso used as shield. Such distribution of the He flow allows a single-run circuit and it avoidsinternal manifolds, which minimizes pressure drop. The module includes two PbLi flow channels(inlet-first wall-rear wall-outlet) with silicon carbide channel inserts (5 mm) with a total length of21 m.6.2.3. TECNO_FUS NEUTRONICS STUDIESA 3D source has been modelled and Tecno_Fus DCLL blanket design has beenanalysed through an iterative CATIA-MCNP optimization process (including the development ofa powerful specific tool for parametric analysis). Tritium breeder ratio, He and T production inPbLi, power deposition, power amplification factor, peak power deposition in toroidal field coilsand He production in EUROFER have been assessed to obtain optimized design parameters.6.2.4 TECNO_FUS AUXILIARY SYSTEMS DEVELOPMENTConsidering the following thermal sources: helium from blanket, liquid metal fromblanket, low temperature helium from divertor and high temperature helium from divertor,different thermodynamic cycles for power conversion cycles, mainly Brayton cycle layoutsbased on He and supercritical CO 2 , have been assessed. Furthermore, heat exchangers basedon Printed Circuit plates have been designed for the considered cycles. On the other hand, apermeator against vacuum to recover tritium from the liquid metal stream has been designedand manufactured and a PbLi loop has been installed in order to test it. More information on theAsociación Euratom – CIEMAT .- Annual Report 2012 109

permeator against vacuum and the experimental PbLi loop facility can be found in 4.3.1.3 and4.3.1.4.6.2.5.TECNO_FUS MHD SIMULATIONS AND ASSESSMENTA CFD tool to analyse magnetohydrodynamics phenomena in PbLi has been developedand qualified. This tool has been implemented in OpenFOAM and includes:Induced magnetic field formulation.Electric potential formulation.2D approach (Sommeria & Moreau, 1982).Hartmann wall functions.Thermal coupling.Advanced thermal boundary conditions.Fluid solid coupling.The code allows calculating MHD pressure drop, liquid metal thermal gain, thermalefficiency, tritium inventories and TPR, as well as correlations between ∆p and h. It has beenapplied to the Tecno_Fus DCLL design (2D thermofluid MHD simulations, sensitivity analysis onvelocity, flow channel inserts thermal performance, etc.).6.2.6. TECNO_FUS TRITIUM MODELLINGA specific solver for OpenFOAM has been developed. It includes the followingphenomena:Helium homogeneous and heterogeneous nucleation.He bubbles transport (passive scalar approach, mean radius approximation,method of classes, quadrature method of moments, poly dispersed phase).T absortion into gas phase.T permeation.Generalized coupled mass transfer.This solver has been applied to model the previously mentioned permeator againstvacuum (tritium transport and permeation, conjugate heat transfer).6.2.7. TECNO_FUS DEVELOPMENT OF MATERIAL PRODUCTION ANDCHARACTERIZATIONPorous silicon carbide with a wide range of different processing parameters has beenexplored:•C10A2.5 (1850ºC, 1h): porosity = 38%;; k = 11.0 W/mK;; σ = 104 ± 7 MPa.Asociación Euratom – CIEMAT .- Annual Report 2012 110

•C10A7.5 (1950ºC, ½ h): porosity = 35%;; k = 13.5 W/mK;; σ = 142 ± 8 MPa.This material includes a dense layer with a uniform thickness of ~ 30 µm and apenetration in the porous layer of ~ 10 µm. Morevover, it shows low thermal conductivity, lowelectric conductivity, low tritium permeability, low corrosion in PbLi and good mechanicalproperties.On the other hand, an EUROFER-type reduced activation ferritic-martensitic (RAFM)steel has been developed and characterised. Several castings have been obtained to date in aVIM (Vacuum Induction Melting) furnace. The results show a fine grain tempered martensitemicrostructure, and the composition and mechanical properties comply with the RAFM steelsrequirements. Hydrogen isotopes permeation tests were also carried out with any concludingresults.Regarding molecular dynamics (MD), a new LiPb interatomic potential that correctlydescribe the properties of eutectic PbLi has been obtained. Simulations give good match ofmany structural, thermodynamic and dynamic properties around the eutectic concentration. H(D or T) has been simulated with classical MD inside Al, Ni and Pd, whereas H diffusion in liquidmetals modelled with EAM potentials is still under discussion. Finally, first steps towards a He-PbLi potential are completed. On the other hand, hybridization phenomena are being discussedand FMM and He bubble simulation is in progress.6.3. FUSION TECHNOLOGY FACILITIES6.2.1. OPERATION OF PRESENTLY AVAILABLE FACILITIES6.2.1.1. OPERATION OF THE VAN DE GRAAF ACCELERATORDuring the year 2012 the 2 MeV Van de Graaff electron accelerator has been operatingfor 30 days corresponding to 170 hours. Electrical and helium and deuterium desorptionmeasurements have been performed during irradiation for SiC, Macor ceramic, LiNbO 3 andAl 2 O 3 . Concerning hydrogen and helium behaviour during irradiation, first experimentsaddressing radiation enhanced deuterium absorption for Macor ceramic and Al 2 O 3 effects havebeen carried out at room temperature making use of the special irradiation chamber anexperimental set up developed during the year 2011. During year 2013 it is planned to modifythe irradiation chamber in order to perform the experiments at higher and more relevantirradiation temperatures.6.2.1.2. OPERATION OF THE “NAYADE” IRRADIATION FACILITYIrradiation of different types of Ge and Siat 2.13 Gy/s and irradiation temperatures of 25C in nitrogen atmosphere have been performed during the year 2012 in the 60 Co NAYADEirradiation facility at CIEMAT.Asociación Euratom – CIEMAT .- Annual Report 2012 111

6.2.1.3. IRRADIATION LINE AT THE CMAM ION ACCELERATORTo date, studies of structural and functional fusion materials have focused on materialbehaviour as a function of irradiation dose, energy, temperature, etc. However, the behaviour ofmaterials under such conditions when a magnetic field is applied simultaneously is stillunknown. In principle, the microstructure and mechanical properties of materials are modifiedby the propagation of defects produced by irradiation, and it is hypothesized that thispropagation may be affected by strong magnetic fields. Therefore, improved knowledgeconcerning the mobility, recombination, clustering or dissociation of defects, as well ashydrogen accumulation, is sought by these experiments and this should increase the knowledgein fusion material characterization field.The sample irradiations analysed here have been undertaken at The Centre for MicroAnalysis of Materials (CMAM), a research center belonging to the Universidad Autónoma deMadrid (UAM) whose main experimental tool is an electrostatic ion accelerator with a maximumterminal voltage of 5 MV, devoted to the analysis and modification of materials.UHP-Fe specimens were irradiated in a series of experiments influenced by 0.8Tmagnetic field with 10MeV Fe +3 ions at temperature of -100ºC. The damage observed by TEMimages took the form of dislocation loops with averaged sizes ranging up to 10 nm in similarirradiation conditions, with and without B. The loop number density was determined to be 5-710 21 m -3 in the case of irradiation under B and slightly lower than without B. In average, verysmall loops have been found in both conditions at a relatively high radiation dose 3.3 dpa, thissuggests the low temperature as a critical parameter to allow larger irradiation-induceddislocation loops. In these experiments loop sizes are much smaller than those expected if theexperiment were at RT of higher, for pure Fe. That means low temperature can inhibit theformation of large dislocation loops.Experiments at RT and higher irradiation dose are underway in order to clarify and quantify the role of magnetic field in material damage.6.2.1.4. PERMEATION AND DIFFUSIVITY FACILITY AT UPVSee Section 4.2.1.3. “Experiments for modelling validation: He desorption in Fe andother model materials“6.2.2. TECHNOFUSIÓN6.2.2.1. INTRODUCTIONThe production of electricity by fusion requires the development of additional researchadvances. The challenge to deal new activities related to fusion technology is, in most cases,the requirement of large laboratories to test prototypes or large facilities to test materials and/orcomponents in extreme conditions. Such facilities are not available for a conventionallaboratory.TechnoFusión (National Centre for Fusion Technologies), founded just after theinitiation of the building process of the International Thermonuclear Reactor (ITER), has beenAsociación Euratom – CIEMAT .- Annual Report 2012 112

conceived as an international reference centre dedicated to research and developing activitiesleading not only the success of ITER as scientific demonstrator, but also the feasibility ofcommercial fusion reactors as energy source for the future. On the 24th of January 2011, theSpanish Centre for Energy, Environment and Technology (CIEMAT), the UniversidadPolitécnica de Madrid (UPM) and the University Carlos III of Madrid (UC3M) signed anagreement to regulate their cooperation in the research project “National Centre for FusionTechnology – TechnoFusión” and to create the TechnoFusión foundation. The Facility willassure the participation of Spanish research groups and companies in the development ofleading fusion technologies. The agreement is a significant step towards in its realisation, as itdefines the administrative framework and thus how the facilities will be built.This project is presently considered one of the few Singular Scientific-TechnicalFacilities of Spain. EURATOM as a European facility also recognizes TechnoFusión for theInternational Fusion Program since its foundation. The programs of inertial fusion by lasers likeLIFE (USA) and LIFT (Japan) have shown interest in TechnoFusión as well.The work areas assumed by TechnoFusión currently include the most criticaltechnologies and knowledge for making a reality to build fusion power plants such as: radiationdamage of materials at large fluencies, plasma-wall interaction, liquid Li technology, remotehandling in hostile environments, development and fabrication of advanced ODS materialsresistant to radiation and high temperatures, techniques for fusion materials characterizationamong them the new secondary ion microanalysis and focused ion beam facilities,computational simulation techniques for assessment of the damage, activation and behaviour ofmaterials and T diffusion.TechnoFusión has also progressed by incorporating exciting new ideas in other areassuch as on physics for inertial fusion technology as well as for magnetic confinement,maintaining the laboratories, designing of new laboratories, and operating setups under theTechnoFusión framework. The nuclear waste management, surveillance of the commercialreactor vessel, prediction of the mechanical behaviour of materials under working conditions,and industrial and medical applications of the nuclear technologies are also other areas whereTechnoFusión can successfully contribute. TechnoFusión, under the agreement betweenCIEMAT, and the UPM and UC3M universities, is already a reality with facilities and researchgroups ascribed in these institutions. The success of the TechnoFusión Workshops held in 2011and 2012, and Summer Courses on TechnoFusión organized in the last years confirm theabove.Besides the scientific and technical initiatives arisen from TechnoFusión, othertremendous profit is the creation of a team composed by scientists and engineers of differentresearch centres and universities working co-ordinately in joint research lines, and makingreality the incorporation of young researcher to a realistic project for giving to our society thepossibility to attain a practically inexhaustible energy source. Is not it what the developedcountries are pursuing?Asociación Euratom – CIEMAT .- Annual Report 2012 113

The funding received from the Regional Government of Madrid and the permanentsupport of Government of Spain have allowed that TechnoFusión pulls off teams of proficientresearchers capable of accomplishing and maintaining the activities of the TechnoFusiónproject, as well as other new technologies required for a safe and profitable use of the nuclearenergy.During year 2012 key activities took place in order to increase the diffusion of theTechnoFusión technical and formation activities. All the generated audiovisual material could beaccessible through the web page(http://programa-technofusion.ciemat.es/TECHNOFUSIONportal/).•A new Summer Course entitled “Computer simulation of Nuclear Fusionsystems: model integration in TECHNOFUSIÓN” was organized on 11-12 of July 2012 withthe support of the Universidad Politécnica de Madrid and directed by Dr. M. Perlado, as ananswer to the great acceptance obtained during the two preceding courses. With theparticipation of more than 20 students, 15 seminars were given emphasizing the objectives ofTechnoFusión in the field of computer simulation: the integration of a commercial fusion reactorglobal simulation, the numerical tools validation, the development of new tools, or the creationof new data acquisition systems and their related results visualization. During the course, thesimulation models for an inertial or magnetic confinement fusion facility design were presented,i.e. models for simulation of plasma generation, of particle transport and their effects, of energydeposition, neutron activation, liquid metal hydrodynamic, of tritium generation, transport andmanipulation, and finally the power cycles of a DEMO reactor.•Continuing the formation activities, fourteen contributions on the progress of thedifferent tasks related to the development of TechnoFusión facilities were presented to morethan 60 attendees to the second TechnoFusión workshop entitled "2nd Workshop on FusionTechnologies and the contribution of TechnoFusión", held on June 2012 at the PhysicsDept, UC3M, Móstoles, Spain. The Proceedings of this workshop are now been organized andcompiled as a book. This publication represents the summary of the TechnoFusión technicaldevelopment achieved up to now.•Also, oral and poster contributions (at least 15) were given and presented indifferent International and National Conferences, where a great deal of enthusiasm for theTechnoFusión facilities was extensively demonstrated.6.2.2.2. IRRADIATION METHODSThe main activities development during 2012 in this TechnoFusión Area are:(a) Design and construction of a sample holder for ion irradiations.Two designs were done during this year. A first one based on the work done during2011. This was in principle a simpler chamber located in the middle section of the line to test theAsociación Euratom – CIEMAT .- Annual Report 2012 114

eam degrader (see next section) but adding more and more diagnostics and features lead to agreater system and a new location was necessary. Therefore the concept changed and thebeam degrader will be finally installed in the large implantation chamber al the end of the CMAMline. Although the design has to change, the major part of the design effort can be re-used in thenew location.(b) Design and construction of a beam degraderActivity carries on with the design of a rotating target with several thin aluminiumsheets. The work has continued the detailed CAD design started in 2011, fixing all the requireddimensions, rotating feedtroughs and accommodation to a new experimental chamber in an ionaccelerator at CMAM (Madrid) and design of the required diagnostics. These include referenceposition of the rotating target, temperature of the foils during operation, rpm control, foilsintegrity control and exit beam energy measurement as the main ones.Tests in the cold rolling machine purchased last year by Ciemat have been done andwe are now able to prepare them.The construction of this energy degrader was delayed to 2013. The main reason is thatwe greatly expanded the scope of the irradiation chamber and it was decided to wait until thewhole design is finished to avoid the need to re-construct the beam degrader itself.This work was also part of a CDTI project with IBERDROLA Company.(c) Viability analysis and conceptual design of a high energy proton irradiationexperimentA high energy proton irradiation facility has been proposed for the ESS-Bilbao (ESS-B)accelerator, currently under construction in Bilbao, Spain. Proton for Materials (P4M) will enableusers to investigate the behavior of materials for fusion reactors when irradiated with pulsedproton beams. The requirement for such a facility was highlighted by the TechnoFusión Projectas the need to improve the knowledge about the mechanical and physical properties ofmaterials when impacted by high energy neutrons in future fusion devices. Therefore, given thatthe ESS-B accelerator will provide an intense source of 50 MeV protons, with average currentsof a few mAs, a laboratory for fusion material testing is proposed [ESS_Bilbao]. The mainresults of the initial scientific feasibility study can be summarized as:1. The 50 MeV proton beam is a useful tool for reproducing radiation damage by fusionneutrons in reactor relevant materials. The use of an energy-beam degrader could also helptoadapt the irradiation conditions to neutron damage in different scenarios.2. Proton irradiation with a current density of 0.1 mA/cm 2 yields a ratio of Heproductionto displacement damage similar to that predicted for fusion neutrons.3. For a 0.1mA/cm 2 beam, active cooling of the rear of the sample is essential in orderto dissipate the thermal load (about 0.7 kW/cm 2 in the sample). A prototype of an Al sampleAsociación Euratom – CIEMAT .- Annual Report 2012 115

holder with a water cooling channel, based on the thermal studies results presented here, isbeing designed.4. Due to the predicted thermal load the mechanical test foreseen during irradiation arenot possible using water cooling in the sample holder. However, simulations using helium gasunder pressure as the cooling medium are in progress.5. Dosimetry during irradiation and activation of sample and holder has been estimated.The results are crucial for defining the experimental conditions and the design of the laboratory.6. A room for remote handling operations has been reserved in the preliminary layoutP4M laboratory because of the high levels of dose and activation expected during/afterirradiation experiments.6.2.2.3. PLASMA-WALL INTERACTIONThe main activity development during 2012 and related to the PALOMA Plasma Gun ofTechnoFusión has been the signed of an agreement with the IPPP Kharkov to achieve theconstruction of a prototype QSPA with no magnetic field to be delivered to CIEMAT in 2013.6.2.2.4. CHARACTERIZATION TECHNIQUESTechnoFusión facility will be able to make a relevant and competitive contribution to thestudy of fusion-induced modifications to materials. Particularly, the CharacterisationTechniques Lab will be provided with a set of advanced devices and techniques for testingmaterials and components the advanced techniques required to undertake studies which eitherhave already been proposed, or which will be proposed in the future. There will be a number oftechniques for testing or characterizing materials before,during and after irradiation due totheir physical, mechanical, structural and compositional changes. In all cases, high-precisiontechniques are required in order to study very small samples, since the three acceleratorsproposed in the framework of the TechnoFusión facility only allow small irradiation areas.During this period of the TechnoFusión technical development, the main objective in theMaterials Characterization Techniques Lab is to establish the feasibility of advanced techniquesfor their application in fusion materials in order to provide the researchers with the appropriatedtools to quali and quantitatively demonstrate the effects of the radiation field and particles inconditions similar to those of a future fusion reactor. All aimed to improve the synergy betweenthe Characterization Techniques Laboratory and the other laboratories of TechnoFusión. Forthis reason, the following actions were undertaken during year 2012.(a) The use of the double beam technology (SEM + FIB) for nanoscale testing ofirradiated materials.A Zeiss Auriga Compact FESEM + FIB instrument was acquired during 2012 anddelivered in January 2013. The new double beam machine was considered the nowadays bettertool for the observation of materials microstructure and in-situ micro/nanoprocessing, theAsociación Euratom – CIEMAT .- Annual Report 2012 116

technology consisting of an ion beam column coupled to a scanning electron microscope. Theanalytical EDS, the scanning transmission and the secondary ion detectors coupled to theAuriga vacuum chamber complete the capabilities of this tool as a micro and nanolab machine.The excellent depth and lateral resolutions of the electron beam allowed the direct and easymicrostructural observation of nanostructures or nanograins.During machine demos it could be demonstrated the already known power of thistechnique for the microstructural studies of ready in-situ prepared cross-sections thanks to thefocussed ion beam as the eroding nanotool. High strength W alloys, ODS steels and Li-basedor SiC ceramics were ion beam sectioned obtaining thin specimens for TEM observations withextremely good results. The extremely fine ion beam polishing (avoiding the so time consumingprocesses of classical polishing and thermal grain highlighting) and the great secondaryelectron detector response made possible to characterize the microstructure of metallicsurfaces preserved from uncontrolled oxidation. Nevertheless, both ion beam induced damageand material loss should be minimized, particularly when irradiated materials would beprocessed.Beam parameters should be controlled and defined to minimize the ion-induceddamage during cutting on already modified materials. It was also verified the ion beamsputtering (or grinding) powerful of fusion materials having complex compositions andmicrostructures or elevated mechanical properties. In fact, after optimizing the sputteringparameters, heavily damaged ceramic samples irradiated with high energy Si 4+ or He+ ion beamsare under preparation to be micromechanical tested.Together with the daily work, the stress for the year 2013 will be the coupling of athermomechanical testing platform to optimize the procedure for in-situ testing of smallspecimen taking advantage of the SEM observation during material deformation at fusionoperational temperatures. Moreover, the whole process (probe fabrication then testing understatic or dynamic stress) could be performed inside the machine initial experiments using pureFe and Fe alloys are underway.(b) SIMS technique as the tool for the depth profiling of light ions in fusion materials.Secondary ion mass spectrometry is a powerful tool for depth profile analysis ofdopants and impurities in solid materials. Moreover, is one of the few techniques able toanalyse very low mass elements (H, D, He, Li, ...), which are of special interest in fusionmaterials as final transmutation products. Particularly the accumulation of He in gas bubbles isknown to produce stress and swelling in the crystalline network, seriously decreasing themechanical properties of structural materials.The end of October 2012 was the date where the LNF_CIEMAT received the HIDENSIMS Workstation, an instrument of 1nm resolution in depth thanks to the precision, low flowO2/Ar ion gun and the sensitive to low mass species cuadrupolar spectrometer. Instrumentoptimization was achieved during the first months, getting very good depth profiles of D or HeAsociación Euratom – CIEMAT .- Annual Report 2012 117

implanted steel and alumina samples, of Li distribution on breeding blankets ceramics, matrixand impurities evolution with depth on SiC, ...A dozen of initial collaborations were arisen in the field of Materials for Fusion but alsoto improve the technique from both an engineering and physical point of view. Emphasis mustbe given to the proposal for the development of new Cu, W-based strengthened alloys and thestudy of derivative oxidation processes in energy production systems due to Fusion using SIMStechnique as the appropriate tool for the in-depth elemental analysis and species distribution.The mentioned alloys are nowadays considered the best candidates for some divertorcomponents in different concepts of future reactors (i.e. DEMO). The development of the SIMStechnique towards a more efficient analysis of He (the noble gas is intrinsically difficult to beionized) has been proposed to direct it into the study of complementary external ionizingsources (laser light, resonant frequencies, ...). The reduction of the H signal is of specialimportance to achieve very low H concentration values using the HIDEN SIMS instrument.Modifications in the chamber actual design has been proposed as a first approach to minimizedor control the residual air.6.2.2.5. LIQUID METAL TECHNOLOGIESMain activities in collaboration with UPM are the following:- The development of liquid metal technologies is a paramount issue on the nuclearfusion pathway. Liquid metals, such as lithium and lead-lithium eutectic, could be the coolantsand the breeding materials of the future fusion reactors.- It was proposed the construction of a R&D laboratory to study the behavior of liquidlithium on relevant environments for nuclear fusion. It was presented an initial proposal of alarge facility that considers most of the issues related to liquid lithium technology [TECHNO_6].Furthermore, the conceptual layout of this lithium loop was reviewed in a book [TECHNO_7]and also it was summarized in an international meeting [TECHNO_8].following:6.2.2.6. REMOTE HANDLINGMain activities developed on Remote Handling in collaboration with UPM are the2012,Secondment at JET by Jorge Barrio from the 22th October to the 1st of DecemberFinalization of the TEMAR (DPI2009-12283) project, funded by ‘Plan Nacional’,Organization of the workshop titled “Telerobotics and Systems Engineering for ScientificFacilities”, the 4th of October, 2012, andContribution to the development of the new ISO standard on Telerobotics for NuclearFacilities.Asociación Euratom – CIEMAT .- Annual Report 2012 118

Jorge Barrio’s work at JET has been focused on the MASCOT actuator’s modeling andanalysis in order to improve its performance. The MASCOT master slave manipulator is usedunder a symmetric position bilateral control scheme. The operator carries out various materialhandling tasks using a master manipulator positioned in a control room, equipped with highdefinition monitors, through which he has visual and force feedback to provide ‘telepresence’.These activities were performed as a result of the problems raised in order to contribute theRemote Handling Group to verify and solve the source of these problems. This secondment hasbeen done in the frame of the GOT-RH project, and funded by EFDA mobility.TEMAR project has been developed by UPM and CIEMAT under DPI2009-12283 grant.This project was focused on developing new techniques and methods for teleoperating robotsunder radiation environments similar to JET or ITER. As result 10 journal and conferencepapers have been published, additionally 1 patent has been registered. These works will becontinued by a new project recently approved titled TELESCALE, under grant number DPI2012-32509.A workshop titled “Telerobotics and Systems Engineering for Scientific Facilities” hasbeen organized in October 2012 at ETS Ing. Indutriales by Manuel Ferre and Jouni Mattila.Experts from remote handling from Europe participated in this event supported by the ITN MarieCurie Puresafe project. Details about program can be obtained in the following url:http://www.romin.upm.es/Puresafe_WS/. n special issue about telerobotics will be published bythe “Int. Journal of Advanced Robotics” with the selected publications.A new standard for telerobotics in nuclear facilities is currently developed by ISO. Thisstandard is lead by CEA-LIST and members from TechnoFusión, José de Nó and Manuel Ferrefrom CAR CSIC-UPM, are currently participating as AENOR experts.6.2.2.7. SIMULATION TECHNIQUES(a) UNED collaboration:During the year 2012 the work done has been related with the development of acoupled system of transport and activation calculations for residual dose assessment. Thissystem called R2SUNED is based on MCNP code for transport and ACAB code for activationcalculations. The approach followed by this tool is the mesh based ones that uses thesuperimposed to the geometry meshes of MCNP to obtain fine spatial resolution of the neutronflux.R2SUNED has been validated in two benchmark exercises proposed by ITER andEFDA respectively ([1] “ITER shutdown dose rate benchmark”. TECF3IR-. J.P. Catalán, P.Sauvan and J. Sanz and [2] “WP12-DTM04-T13: study of transport-activation couplingschemes. D15a: comparison exercise of R2S and D1S SDR tools.”R. Pampin, J.P. Catalan, D.Leichtle, A. Turner and S. Villari.). The ITER benchmark was defined in 2010 by ITERorganization and it consists in a simple cylindrical geometry with gaps and materialsrepresentatives of ITER reactor. The results obtained in this benchmark were very successful.Asociación Euratom – CIEMAT .- Annual Report 2012 119

The EFDA benchmark is based on a detailed DEMO reactor (HCLL) and, for this reason, it isvery hard in computational terms. This benchmark was proposed by R. Pampin under EFDAwork programme 2012 in the task WP12-DTM04-T13 and it is a blind exercise. The resultsobtained were very successful.This tool has been applied to different DEMO facilities: DCLL CONSOLIDER reactor(“Shutdown dose rate assessment for a DCLL blanket-based reactor: Application of the R2S-UNED approach”. J. P. Catalán, P. Sauvan and J.Sanz.) and HCLL DEMO1 EFDA reactor(“Calculations of in-vessel and ex-vessel radiation conditions during shutdown periods”. J. Sanz,J. P. Catalán, R. Juárez and P. Sauvan). The calculations make for both reactors are relatedwith the characterization of the radiation environment for remote handling maintenance. TheHCLL reactor study has been made under the EFDA task WP12-DAS06-T03.(b) UPM collaboration:UPM group was actively contributing to the ICTS TechnoFusión in different aspects as:design of laboratories, design of experiments, simulations for new installations, evaluation ofcodes and proposing science for study in TechnoFusión. This group has contributed to the 2012TechnoFusión workshop [TECHNO_1], [TECHNO_2], [TECHNO_3] and in addition it waspresented a TechnoFusión for the laser fusion community during the CLIFE meeting in Japan[TECHNO_4], [TECHNO_5].6.2.3. IFMIF (OUTSIDE OF THE BROADER APPROACH AGREEMENT)6.2.3.1. USE OF IFMIF/EVEDA FACILITIES FOR MATERIALS DEVELOPMENTIn the framework of the IFMIF-EVEDA project, a prototype accelerator will beconstructed and operated to demonstrate the feasibility of the Accelerator system foreseen forIFMIF. The potential uses of this prototype accelerator for possible materials irradiationexperiments were analysed. Without entering into details the irradiation conditions in the beamdump area was assessed. Although the damage function that one can expect in the beam dumparea is similar to that in DEMO tritium breeder zone the damage rate is around 4000 timeslower (x10 -5 ). The Beam dump of the LIPAC is not a good area to perform relevant irradiationexperiments of structural materials for the design of the nuclear fusion reactor DEMO.Additionally, irradiation of specimens in the Beam Dump would require some changes inthe design of the Beam Dump which would interfere with the overall LIPAc schedule foreseenfor Construction, Licensing, Commissioning and Operation. The expected outcome does notworth the required changes and the consequent interference ion the schedule.An alternative could be the substitution of the Beam Dump by a target designedspecifically designed to produce a radiation field useful for materials experiments. Such achange would require additional facilities for shielding, remote handling, etc. Such alternativewould involve major changes in the whole facility and major investments. The theoreticaloutcome on materials irradiation should be first carefully assessedAsociación Euratom – CIEMAT .- Annual Report 2012 120

6.2.3.2. COMPARISON OF DIFFERENT IRRADIATION FACILITIESA rigorous material testing program is essential for the development of the nuclearfusion world program. In particular, it is very important to predict the generation of thedisplacement damage in materials, because the irradiation intensity expected in fusionconditions is such that the performance of materials and components under these extremeconditions is unknown. To study the damage produced by neutrons in materials of interest forfusion, a specific computational methodology was developed. Neutron fluxes expected indifferent irradiation facilities (International Fusion Materials Irradiation Facility [IFMIF] andDEMO-HCLL) and in different irradiation spots were obtained with particles transport codes(McDeLicious, MCNP). The energy differential cross sections of primary knock-on atoms werecalculated using the NJOY code. Resulting data were input into the Monte Carlo codeMARLOWE to calculate the corresponding displacements (i.e., interstitials (I) and vacancies(V)). However, the number of Frenkel pairs created during irradiation strongly depends on therecombination radius between interstitials and vacancies. This parameter corresponds to theminimum distance below which instantaneous recombination occurs. Mainly, the influence ofsuch parameter on the damage function in Al2O3 was assessed in thisreport. Thedisplacements per atom values calculated as a function of the recombination radius consideredare compared to experimental data to determine the most appropriate capture radius. Inaddition, the damage function and damage dose generated at different experimental irradiationfacilities are compared with those expected in DEMO. The conclusion is that both IFMIF andTechnoFusión (future triple beam ion accelerator to emulate fusion neutron irradiation effects inmaterials) facilities are suited to perform relevant irradiation experiments for the design ofDEMO [IRR_FACILITIES]Asociación Euratom – CIEMAT .- Annual Report 2012 121

7 INERTIAL CONFINEMENT FUSION, KEEP IN TOUCH ACTIVITIES7.1. SCIENTIFIC DEVELOPMENT IN TARGET DESIGN7.1.1 RADIATION HYDRODYNAMICS AND ATOMIC PHYSICSX-Ray Laser.We have continue with the design of a high power X-ray laser, both improving theamplifier and using CPA-like technique to increase the power [REF_RAD_HYD_1] of the laserbeam. We finish the time dependent ionization model integrated in the ARWEN code.We have developed a model for X ray laser interaction with matter in the fs scale, with atime dependent atomic physics and electronic distribution evolution according to a Fokker-Planck equation. [REF_RAD_HYD_3] [REF_RAD_HYD_4]Astrophysical Lab.During this 2012 year we have worked in the development and improvement of anhydrodynamic simulation code suitable to study plasmas in the high energy density regime likethose produced in astrophysics systems. Moreover this code has been used to study theformation of radiative shock in size-scaled systems suited for laboratory experiments related tothis astrophysical phenomenon. [REF_RAD_HYD_5]This simulation program has been improved including the ability to deal withmultimaterial systems in the radiation transport models and also has been added the capabilityto include non-equilibrium effects in the calculation of the plasma radiative properties.Target simulations.Fast ignition (FI) is an attractive scheme of laser fusion. In FI, at first, high-density fuelcore plasma is assembled by implosion laser and then, just around the maximum density time, itis heated by petawatt laser to achieve a fusion burning condition. In the last year we havecollaborated with the ILE (Osaka) in the studying of the implosion dynamics. A half-spheretarget have been simulated with ARWEN, the hydrodynamic code with radiation transport inAMR developed at Instituto de Fusión Nuclear (UPM).7.1.2. Atomic PhysicsDuring 2012 activities related with atomic physics have been oriented in to spread theuse of the two computer codes: ABAKO/RAPCAL and ATMED, in several applications and alsoin adding up more physics.The code ABAKO has been used in the analysis of experiments carried out atRutherford Appleton Laboratory to characterize blast waves launched in Xe clusters[REF_ATOMIC_1]. This analysis is very important because low density material with highatomic mass is suitable to achieve radiative regime, and, therefore, low density Xe gas iscommonly used for the medium in which the radiative shock propagates. The average ionizationAsociación Euratom – CIEMAT .- Annual Report 2012 122

and the thermodynamic regimes of xenon plasmas are determined with the use ofABAKO/RAPCAL, as functions of the matter density and temperature in a wide range of plasmaconditions.Relativistic Screened Hydrogenic Model (ATMED code) has been modified in the senseof to calculate atomic data for NLTE steady state plasmas. This modification has produced animportant change because now is able to compute optical and thermodynamic properties ofplasmas in both LTE and NLTE regimes.Additionally, computation of dipole matrix has been improved in the RSHM, because ithas an important role in the study of the absorption or emission of radiation by atoms in severalfields such as astrophysics, inertial confinement fusion and laser applications, among others[REF_ATOMIC_2].International collaboration was kept during this time mainly with European laboratoriesas: Imperial College, RAL, University of Check Republic; also with laboratories and universitiesin USA, as: University of Reno, University of Michigan, Lawrence Livermore National Laboratoryand University of Rochester. Under the agreement with Osaka University, atomic physics forIFE and astrophysical plasmas are the main topics, and also photo ionized plasmas. We haveparticipated in the 39Th EPS Conference on Plasma Physics in Stockholm, and in theInternational Conference on Fusion Energy (CIFE 2012) in Yokohama (Japan)7.2. PHYSICS AND TECHNOLOGY IFE (AND MFE) SYSTEMS7.2.1. STATE OF THE ART INERTIAL FUSION ENERGY BY LASERR&D pathway for Inertial Fusion Energy must complete two important milestones,scientific and technological viability. The National Ignition Facility (NIF) in Lawrence LivermoreNational Laboratory (LLNL) and Laser Mega Joule (LMJ) under construction at CEA/CESTAresearch center in France are the high-power laser facilities, which are approaching thedemonstration of ignition and burn. In France PETAL project to be used in combination withLMJ will give an opportunity to have a PW laser in connection with a quad of the large facility oflarge energy for compression such as LMJ. In addition, different ignition schemes such as fastignition, shock ignition and impact ignition are progressing in the Fast Ignition RealizationExperiment (FIREX) at the Institute of Laser Engineering (ILE), Osaka University, and theOMEGA-EP project at the Laboratory for Laser Energetics (LLE), University Rochester, and theHiPER project in the European Union (EU). Besides the laser technology developments,projects of demonstrator power plants, HiPER in Europe. LIFE in USA, and LIF_T in Japan (withidea of projects progressing in China and Russia) are making important improvements in theIFE technology R&D.Asociación Euratom – CIEMAT .- Annual Report 2012 123

During 2012, the goal of the Insituto de Fusión Nuclear in reactor materials have beento identify and study real problems of an Inertial Fusion Device starting from target emission topower cycles extraction [REF_IFE_SYSTEMS_1].The work performed by the Instituto de Fusión Nuclear in Madrid has been very much incollaboration with Rutherford Appleton Laboratory, Commisssariat lÉnergie Atomique enPrague Asterix Laser System (PALS) inside HiPER European Project, and also with two majorinternational collaborations through correspondent Memorandum of Understandings (MoU)where key aspects of collaboration are the full development of elements in IFE Systems andPhysics from Target design to Reactor integration: LIFE with Lawrence Livermore NationalLaboratory and the Institute of Laser Engineering (ILE) of the University of Osaka in thedevelopment of the IFE System LIFT.7.2.2. MATERIALS ADVANCED UNDER IRRADIATION AND CHAMBERDYNAMICS FOR IFEIrradiation of Fusion Materials by Laser driven particles.The lack of irradiation facilities to reproduce the ions and X-ray conditions of InertialConfinement Fusion Reactors for the validation of plasma facing components was evidenced. In2011, ultra intense lasers were proposed as a powerful tool to generate ion and x-rays burstswhich, to date, best fit the plasma conditions of ICF systems. This proposal has been describedand presented in different publications [REF_MAT_1], [REF_MAT_2], [REF_MAT_3],[REF_MAT_4]. Initial experimental shots at the Central Laser Facility in UK have demonstratedthe viability of such proposal. At present, in collaboration with Prof. Neely, Prof. Mckenna, Prof.Borghesi and Dr. S. Kar, we are submitting proposals to LaserLab Europe to carry out suchexperiments.So far, an important effort has been placed on the generation and characterization ofthe laser driven protons beams in terms of a parametric optimization of the process anddetection tools [REF_MAT_5].In parallel, a review of the state of the art of Laser driven neutron sources has beenelaborated and presented in international conferences on neutron sources [REF_MAT_6]. Atpresent, Laser neutron sources might not reach the fluxes necessary to test fusion materials butthis fact is expected to change in the near future, opening a more cost-effective way ofvalidating nuclear radiation damage.TMAP simulations on diffusion of light species in First Wall materials.The group has continued to work on the simulation of diffusion of light species (Hisotopes and He) in First Wall materials, in particular W. Making use of the diffusion codeTMAP, several calculations have been carried out to estimate the retention and re-emission ofimplanted species for the conditions of HiPER4a and HiPER4b designs [REF_MAT_7]. Thegoal of these calculations is to have a complete picture of the diffusion and retention of HAsociación Euratom – CIEMAT .- Annual Report 2012 124

isotopes and He in all components of a fusion reactor (be those implanted in the plasma facingcomponents, those generated by transmutation due to neutron irradiation of structural materialsor those generated in a future breeding blanket). In particular, those simulations dealing withTritium will contribute in the evaluation of Tritium inventory and handing of any fusion facility.Thermo-mechanical simulations of plasma facing materials.Thermo-mechanical simulations on final optics of IFE have been carried on by means offinite elements under three scenarios for the European project HiPER (experimental, prototypeand demo facility). In continuous mode prototype and demo, neutron irradiation heats the lensand generates colour defects that absorb laser irradiation. As conclusion, lens temperaturemust be constant during start-up and operation mode to avoid focal length variations. Inaddition, the position of final lenses in demo scenario must be redesign because at 8 meters thetemperature is over the maximum service temperature [REF_MAT_8]We have also studied the mechanical response and crack damage due to ion irradiationin ceramics. In particular, simulations with finite elements in LiNbO3 show the stress fieldgenerated by nano-tracks near the surface that leads to a swelling of the material and crackfracture at determinate fluence [REF_MAT_9] [REF_MAT_10] [REF_MAT_11].A methodology has been assumed to calculate the mechanical fracture of plasmafacing materials, first wall and final lens. First energy deposition is calculated, then thermomechanicalbehaviour is obtained, and finally we calculate the crack growth [REF_MAT_12].Neutron irradiation laboratory at ESS Bilbao.We have hired a PhD student to develop in collaboration with colleagues from the futureneutron source ESS Bilbao (currently under construction) to design a neutron irradiationlaboratory for preferential use in studies of ceramic materials (e.g., lenses) exposed to neutronirradiation in a future laser fusion power plant. This work has been presented at the UCANS2012 meeting [REF_MAT_13].Ion irradiation of optical components.Along this year we have devoted a large effort to studies on silica and quartz samples(and for comparison other dielectric materials) exposed to swift ions. To certain extent thisconstitutes a fundamental work, but it is more than that because swift ions will be ubiquitous inlaser fusion plants and they will certainly affect the involved optical materials, particularly, thefinal lenses. We have studied the kinetics of amorphization of quartz [REF_MAT_14]; colourcentres [REF_MAT_15] [REF_MAT_16]; changes in the refractive index [REF_MAT_17];ionoluminescence [REF_MAT_18] [REF_MAT_19]. As an important by product we have appliedthis knowledge for waveguide fabrication [REF_MAT_20] and we have even published a bookchapter devoted to this topic [REF_MAT_21]. In addition to these publication we have presentedthese works in different conferences MRS 2012 Boston [REF_MAT_22]; COSIRES-ICDIM 2012Santa Fe [REF_MAT_23], [REF_MAT_24], [REF_MAT_25]; IBMM 2012 Qingdao[REF_MAT_26], [REF_MAT_27], [REF_MAT_28].Asociación Euratom – CIEMAT .- Annual Report 2012 125

Object kinetic MonteCarlo simulations of He in tungsten.Tungsten has been studied to understand its viability as an armour material. Theinteraction of He with W, in particular the high He retention, has been identified as a seriousproblem. We have contributed to the development of a sophisticated new MonteCarlo code foradvanced simulations (presented in COSIRES-ICDIM 2012 Santa Fe [REF_MAT_29] currentlyin press). In the same conference we presented and published the first results on the effect ofHe pulses vs. continuous He irradiation [REF_MAT_30], [REF_MAT_31]. The results clearlyindicate that pulsed irradiation (e.g., in a laser fusion reactor) is much more detrimental thancontinuous irradiation (e.g., in a conventional ion accelerator). This explains previousexperimental results reporting much lower threshold damage in the former case.Molecular dynamic simulations of Fe structural material.Studies of the effect of Cr content on the stability of FeCr alloys defects have continued.Formation and binding energies for vacancy clusters up to 5 units have been performed as afunction of the Cr concentration. Cr concentrations under study are 0%, 1% 5%, 10% and 15%Cr. First of all, the most stable geometry for each cluster size has been determined. Once themost stable configuration for each cluster size has been found, it will be our starting geometryfor the systematic study of the cluster formation energy with Cr concentration. Since the localposition of the defect with respect to the Cr atoms in substituted positions could influence theformation energy value, we have explored all the possibilities of the cluster position for eachconcentration and cluster size geometry. These calculations have been performed with twoempirical potentials specially developed to study radiation damage in FeCr alloys: the modifiedversion of the concentration dependent model (CDM) we have used in previous works, and thetwo band model (2BM). Results are very similar for both potentials showing an increase of thedefect stability with the cluster size and no real dependence on Cr concentration for the bindingenergy. [REF_MAT_32]Ab initio simulations for target material, hydrogen Isotopes.The system targets in inertial confinement fusion is based on the nuclear ignition of acapsule filled with deuterium-tritium, the way this capsule is placed in contact with theDeuterium Tritium design varies, however in every one of them, this layer of deuterium tritium issolid state molecular, manufactured cryogenic temperatures and low pressures. Eventually thecapsule is exposed to laser energy directly or indirectly producing very high pressures andtemperature variation also very high.The changes that occur during the various stages of compression of the targetcontaining both the metal fuel, such as fuel same deuterium-tritium are not fully known.As a first approximation we study phase changes occurring in the deuterium-tritiumlayer without the presence of the capsule container [REF_MAT_33], to this end we startedstudying solid hydrogen simulating structures. These models are based on the application ofAsociación Euratom – CIEMAT .- Annual Report 2012 126

first principles methods, by use of SIESTA code, that performs calculations of the electronicstructure of solid approaches using DFT [REF_MAT_34].With this methodology have been reproduced various experimental parameters, wehave studied the phase transitions, and atomic structures have been proposed. Likewisethrough the implementation of the molecular dynamics of these systems further phasetransitions were obtained parameters of interest in the engineering design targets, as is thecompressibility modulus or the speed of sound for these structures [REF_MAT_35].Our simulations are validated through comparison with experiments on hydrogen anddeuterium, through the speed of sound. This latter result to us a series of discontinuities shownin the variation of the speed of sound pressure, that have not been fully addressed in the stateequations used for simulation macroscopic scales [REF_MAT_36]. All calculations were carriedout for samples ranging from 200 to 1000 atoms in the temperature range from 5 to 400 K, andpressure from 0.001 to 400 GPa.MD of nanoparticulate metallic materials: Aluminium, Gold and Tantalum.Already in high Z elements have proposed to study in Molecular Dynamics using theLAMMPS code, and SIESTA. Tests have been performed on these systems to have a goodparameterization of the same. These systems nanostructured metallic materials have also beensimulated for conditions of high pressures, with some preliminary results [REF_MAT_37]Preliminary calculations were made to vary the properties known as solid molecularhydrogen in a nanostructured arrangement [REF_MAT_38] method by which it is expected toimprove the conditions of manufacture and efficiency of the ignition [REF_MAT_39]. This isexpected to propose in three years a series of experiments on different systems at highpressure containment materials to study some assumptions thrown by our simulations.Deposit of nanostructured W for first Wall application.W has been proposed to be one of the best candidates for PFM for both laser (IC) andmagnetic (MC) confinement fusion approaches. However, works carried out up to now haveidentified some limitations for W which have to be defeated in order to fulfill specifications.Nowadays, the capabilities of ultrafine grain and nanostructured materials for nuclear fusionreactor applications are being investigated.We have deposited nanostructured tungsten coatings with a thickness up to 5m byusing DC magnetron sputtering. We have studied the influence of the deposition conditions (gaspressure and cathode voltage) on the coating microstructure. Moreover, we have also studiedthe microstructure, morphology (in particular grain size), stress state and mechanical properties(harness and Young´s modulus) as a function of coating thickness. For optimized parameters,Scanning and transmission electron microscope (SEM and TEM) images show that coatingsconsist of nano-columns with an average diameter of around 100 nm and a cylindrical shapethat grows perpendicular to the substrate. X-Ray diffraction (XRD) studies show that coatingsAsociación Euratom – CIEMAT .- Annual Report 2012 127

are pure -phase and polycrystalline. Moreover, optimized coatings show good adhesion to thesubstrate and hardness as high as ~14 GPa [REF_MAT_40] [REF_MAT_41] [REF_MAT_42].Study of light species behavior nanostructured W.The retention of light species is a point of concern when assuming W as PFM. Lightspecies (mainly H, D, T and He), which are present in the plasma in magnetic confinementfusion (MC) and which result from the explosion in inertial confinement fusion (IC), areimplanted in the near surface region of PFM, leading to the formation of bubbles which notablydegrade W mechanical properties and heat load performance. The role of grain boundaries inthe light species behavior is still under debate.We have studied the hydrogen behavior in nanostructured (NW) films as compared tocoarse grained W (CGW). For this purpose resonant nuclear reaction (RNRA) experiments arecarried out in collaboration with Helmholtz-Zentrum Dresden-Rossendorf (Germany) by usingthe 1 H( 15 N,αγ) 12 C nuclear reaction in NW and CGW samples implanted with (i) H at an energyof 170 keV and (ii) sequentially implanted with C (665 keV) and H (170 keV). Implantations werecarried out at a fluence of 5x10 16 cm -2 and at two different temperatures RT and 400ºC. RNRAdata evidence that the H concentration for samples implanted only with H is higher for NW thanfor MW, and it becomes comparable for both kind of samples after sequential implantation withC and H. Increasing the temperature during irradiation up to 400ºC leads H to completely outdiffuse in NW as well as, in CGW samples. Actually the microstructure, morphology andmechanical properties of implanted samples are being investigated [REF_MAT_43].Ion beam analysis of as-received, H-implanted and post implanted annealedfusion steels.The elemental distribution for as-received (AR), H implanted (AI) and post-implantedannealed (A) Eurofer and ODS-Eurofer steels has been characterized by means of microParticle Induced X-ray Emission (-PIXE), micro Elastic Recoil Detection (-ERD) andSecondary Ion Mass spectrometry (SIMS).The temperature and time-induced H diffusion hasbeen analyzed by Resonance Nuclear Reaction Analysis (RNRA), Thermal DesorptionSpectroscopy (TDS), ERDA and SIMS techniques. -PIXE measurements point out thepresence of in homogeneities in the Y distribution for ODS-Eurofer samples which might notablyinfluence their mechanical properties. Moreover, a small percentage of hydrogen was foundalong the whole investigated depth for as-received samples, which indicates that H incorporatesinto the steel during its manufacturing in a H 2 -rich atmosphere. RNRA and SIMS experimentsevidence that hydrogen easily out diffuses in these steels even at room temperature. This roomtemperature diffusion is responsible for the strong decrease of the hydrogen concentration withtime. The H depth profiles suggest that the sample surface might play an important role in thehydrogen release. Indeed, a higher hydrogen concentration is detected in the near surfacelayers, which may indicate that the surface strongly reduces somehow the hydrogen releasing.ERD data show that annealing at temperatures as low as 300 ºC strongly accelerates theAsociación Euratom – CIEMAT .- Annual Report 2012 128

hydrogen diffusion process, driving out up to the 90% of the initial hydrogen to out diffuse[REF_MAT_44].Molecular Dynamics simulations on screw dislocation mobility in tungsten.Dislocation mobility calculations are computationally intensive and highly parametric.Under these circumstances, we have studied different techniques to accelerate convergence ofstress-controlled simulations of dislocation motion [REF_MAT_45]. We conclude that simpleshort 'ramps' are sufficient to dampen stress oscillations that require nearly one order ormagnitude more to reach when stress is applied as a sudden step.We have also completed the assessment of interatomic potentials for atomistic analysisof static and dynamic properties of screw dislocation in W [REF_MAT_46] concluding thatmodified embedded-atom potential achieves the best compromise in terms of static anddynamic screw dislocation properties, although at an expense of about ten-fold compared tocentral potentials.All these results have been obtained in full collaboration with Lawrence LivermoreNational Laboratory.7.2.3. IFE SYSTEMS: REACTION CHAMBER, SAFETY AND RADIOPROTECTIONReaction Chamber of HiPER Reactor.Along 2012, the studies started in 2011 were continued and finished. Consequently, thereaction chamber under study is a self-cooled lead lithium blanket based chamber with dry walltechnology for the first wall. The studies carried out in 2012 covered the following aspects of theproposed reaction chamber:Neutronics of the chamber and activation of the LiPb eutecticThe Helium Brayton power cycle for power conversionLocal maximum temperature and local corrosion ratesVacuum Vessel shape for maintenance reasonsAll the work cited here and carried out along 2012 has been included in a PhD. named“Neutronics Design and radiological aspects of the HiPER facilities”, by Rafael Juárez. ThePhD. has been codirected, during 39 months, by the Universidad Politécnica de Madrid andUniversidad Nacional de Educación a Distancia.The neutronics and activation studies of the reaction chamber were oriented to make aselection between a thick (75 cm) and a thin (50 cm) breeder. By changing the 6 Li enrichment ofthe LiPb (25% and 75% respectively), the same TBR=1.1 can be obtained with differentthicknesses of LiPb. The final decision will ultimately affect many chamber aspects, starting withthe total weight. But the impact of this decision was also evaluated in terms of tritium partialpressure and total inventory in the loop, 210 Po and 203 Hg degree of radiological confinementAsociación Euratom – CIEMAT .- Annual Report 2012 129

equired and radiological protection to the vacuum vessel. The thin blanket showed a superiorperformance in terms of tritium, 203 Hg and 210 Po production, but a worse performance in theradiological protection of the Vacuum Vessel. In fact, a 52 cm thick vacuum vessel is required toguarantee the reweldability of the external surface of the vacuum vessel after forty years ofoperation, in the case of the thin blanket. In the case of the thick blanket, a 39 cm thick vacuumvessel is required, being both clearly far from the maximum 20 cm fixed in the projectrequirements. Thus, a thin blanket was selected for further design evolution, with the advice thatan additional shielding for the vacuum vessel will be required. A preliminary neutron reflector ofgraphite of 20 cm of thickness is under study, allowing a 20 cm thick vacuum vessel in the caseof the thin blanket. This reflector also allows reducing the 6 Li enrichment from the initial 75% toa 20%, with evident economics advantage. This work was partially included in the presentationof the HiPER fellows meeting 2012 in Bordeaux, France [REF_BLANKET_1], and fully coveredin the poster presented in the Symposium on Fusion Technology 2012, in Liege, Belgium(SOFT 2012) [REF_BLANKET_2]. As a result of this conference, a paper was sent to FusionEngineering and Design, and it is currently under review.With respect to the 2011 studies on the helium Brayton cycle, the First Wall - Blanketcooling configuration was decided to be separated. Consequently, while the LiPb in the blanketis self-cooled, the first wall is cooled with helium branch from the secondary circuit. Thesecondary circuit is a helium loop operating a Helium Brayton cycle. The temperatures range ofthe blanket is 350 ºC – 450 ºC, while the range for the First Wall is >350ºC – 650ºC. For thisconfiguration, several layouts of helium Brayton power cycle were analyzed to reach the cycleoptimal performance in terms of cycle thermal efficiency. Also, sensitivity analyses were carriedout to quantify the effect of the key cycle parameters on the maximum thermal efficiency.Efficiencies around the 37% are obtained even when considering the real performance of thecycle components and pressure drops in the heat exchangers. As a result of this study, theHelium Brayton power cycle for the SCLL reaction chamber of HiPER reactor is fully studiedand finished [REF_BLANKET_3]. This work was partially included in the presentation of theHiPER fellow meeting 2012 in Bordeaux, France, and fully covered in the poster presented inthe Symposium on Fusion Technology 2012, in Liege, Belgium (SOFT 2012). Nowadays, it isunder study a supercritical CO 2 Brayton cycle for this HiPER reactor reaction chamber.Regarding the fluid-dynamics studies, along the year 2011, severe problems werefound in the blanket performance, for both Integrated and Separated First Wall Blanketconfigurations. On one hand, in order to not reach the local maximum temperature of 550ºCallowed by the EUROFER, the mass flow must be so high that the outlet average temperatureresults to be very low (390ºC instead of the 450ºC desired). In spite of the high mass flow, therewas an area with insufficient cooling so that very high corrosion rates were reached (over 600m/yr in the best case, when the limit was fixed to 200 m/yr). Both problems arise from arecirculation taking place after the first beam penetration in the inner duct. It is the result of anobstacle in fast flowing but slowing down section in a very 2D flow pattern. During the year2012, there was a deep research on how the computational model for the fluid turbulence couldAsociación Euratom – CIEMAT .- Annual Report 2012 130

affect to this results. By using RANS type models, which average quantities in large regionswhile allow “fast” simulations, the results were similar. However, using a LESS model, muchmore detailed but highly computer consuming, with higher physical relevance, the recirculationdisappeared, showing to be a computational phenomenon, with no connection to the physicalreality. The RANS models were not suitable to simulate the LiPb in the recirculation area(Reynold’s number around 10 8 ), giving wrong answers. Consequently, the blanket design isbeing faced taking into account these results. The LiPb circuit will be modified to avoid in theextent possible the appearance of recirculations, but the preliminary results indicate a lessdramatic performance than that found in 2011. Currently, the blanket performance is beingevaluated using the LESS model to reach an answer on the local maximum temperature andcorrosion rates. This work was partially included in the presentation of the HiPER fellow meeting2012 in Bordeaux, France.Finally, it was found that the spherical vacuum vessel proposed along 2011 wasunsatisfactory from many perspectives. Apart from the structural and constructability difficultiesof such a chamber, the most limiting aspects were two: 1) the spherical shape with R=8m didnot allow to host a reasonable structure for the blanket while allowing an easy maintenance ofthe blanket, the first wall or the vessel itself, and 2) the third ring of lasers position seriouslydisturb the ex-vessel maintenance of components, as it obstructs hypothetical opening doorsand implies pipe cutting for in-vessel access of machinery and extraction of components. Alongthe 2012, a cylindrical vacuum vessel was proposed, with radius of 10 m. To do so, the opticsarrangement was changed, an mirrors were introduced in-vessel in the third lasers ring as finaloptics, instead of lenses. The new vacuum vessel allows an efficient systems grouping tooptimize the maintenance tasks, presenting very large free spaces and rooms devoted toisolated systems. This work was partially included in the presentation of the HiPER fellowmeeting 2012 in Bordeaux, France.Nuclear data uncertainly in activation calculations.In activation calculations, there are several approaches to quantify uncertainties:deterministic by means of sensitivity analysis, and stochastic by means of Monte Carlo. Wehave studied two different Monte Carlo approaches for nuclear data uncertainty: the first one isthe Total Monte Carlo (TMC). The second one is by means of a Monte Carlo sampling of thecovariance information included in the nuclear data libraries to propagate these uncertaintiesthroughout the activation calculations. This last approach is what we named CovarianceUncertainty Propagation, CUP. In this reference, both approaches and their differences arepresented and compared by means of an activation calculation, where the cross-sectionuncertainties are propagated [REF_SAFETY_1].Processing of the JEFF-3.1.2 Cross Section Library into various formats (ACE, PENDF,GENDF, MATXSR and BOXER) for testing purposes is presented in Ref. [REF_SAFETY_2].The JEFF-3.1.2 cross section data file is processed into MCNP/ACE application libraries fordifferent temperatures depending on the application needs. The nuclides processed are thoseAsociación Euratom – CIEMAT .- Annual Report 2012 131

of the General Purpose Library. The library at 300K is verified and compared to other availablelibraries (JEFF-3.1.1, ENDF-B/VII.0 or VII.1) using JANIS and PREPRO code. A QualityAssurance procedure is used producing the data library, pointing out any error/mistake foundduring the analyses. The processed data contain gamma production and gas production data,kinematic KERMA factors and total damage energy data.In addition, UPM Activities on the STLs processing and the generation of DPA crosssection library is presented in Ref. [REF_SAFETY_3]. For, the complete damage energy anddpa cross section library an extended evaluation up to 150 MeV based on JEFF-­‐3.1.1 isperformed. Post-processing of photonuclear libraries is also included in this work.Calculations of Fission Pulse Neutron Emission: A comparison between JEFF-3.1.1 andENDF/B-VII.1 are performed in collaboration with CIEMAT [REF_SAFETY_4]. The objective isto analyze the present status of Evaluated Decay Data and Fission Yield data libraries to predictthe neutron emission rate and the average neutron energy and neutron delayed spectra.Moreover, the prediction of “uncertainties” due to the current uncertainties in these Nuclear DataLibraries is carried out with our activation ACAB code (NEA-1839, ACAB-2008).Consequences of Different Meteorological Scenarios in the Environmental ImpactAssessment of Tritium Release.Refined environmental tritium dose impact assessment schemes are thenoverwhelming. Detailed assessments can be procured from the knowledge of the real boundaryconditions of the primary tritium discharge phase into atmosphere (low levels) and into soils.Lagrangian dispersion models using real-time meteorological and topographic data provide astrong refinement. Advance simulation tools are being developed in this sense. The toolintegrates a numerical model output records from European Centre for Medium range WeatherForecast (ECMWF) with a lagrangian atmospheric dispersion model (FLEXPART). Thecomposite model ECMWF/FLEXTRA results can be coupled with tritium dose secondary phasepathway assessment tools. Nominal tritium discharge operational reference and selectedincidental ITER-like plant systems tritium form source terms have been assumed. The real-timedaily data and mesh-refined records together with lagrangian dispersion model approachprovide accurate results for doses to population by inhalation or ingestion in the secondaryphase [REF_TRITIUM_1].Modelisation of the transport of tritium forms (HT and HTO) for evaluation of the impactin fusion. The process of atmospheric dispersion of Tritium and the best possible modelisationof the transport of tritium forms (mainly fluxes of tritium hydride HT and HTO) for evaluation ofthe impact in fusion in a potential emergency case. In other words the aim of this work is toconsider different short-term releases of tritium fluxes (mainly fluxes of tritium hydride in bothchemical forms) to the atmosphere from a potential ITER-like fusion reactor located in theMediterranean Basin and their tritium flux differences - inland and over the Mediterraneanscenery - when different releases shows an HT flux or HTO flux decrease in air. At the sameAsociación Euratom – CIEMAT .- Annual Report 2012 132

time in those cases, wet (due precipitation) or dry depositions may increase locally. This allowsus for explore the HTO/HT ratios and to analyze the tritium decrease in air.We explore specific values of this ratio in different levels and we examine the influenceof meteorological conditions in the HTO behavior for 24 hours. Therefore HT or HTOconcentrations and flux rate can be characterized. For this purpose we have used a tool whichconsists on a coupled Lagrangian ECMWF/FLEXPART model. This tool was analyzed fornominal tritium operational conditions under selected incidental conditions to determineresultant local HTO and Western Mediterranean HT effects, together with hourly observations ofwind (and in some cases precipitations) to provide a short-range approximation of tritium cloudbehavior. Actually we have examined the HTO/HT ratio in those levels in a representative set ofcases during winter and spring for the 3 air levels. Finally we explore deposition of tritium flux byits contribution to doses by inhalation, taking into account key factors for high dose rate zones:rainfall (wet deposition), dry deposition and topography in the inland scenery[REF_TRITIUM_2], [REF_TRITIUM_3], [REF_TRITIUM_4]__________________________Asociación Euratom – CIEMAT .- Annual Report 2012 133