Chamber Responses and Safety and Fusion Technology in HiPER facility

Transcription

1 Chamber Responses and Safety and Fusion Technology in HiPER facility J. M. Perlado Instituto de Fusión Nuclear (DENIM)/ETSII Universidad Politécnica, Madrid, Spain Thanks to Co-authors J. Collier*, C. Edwards*, M. Tyldslay*, L. Gizzi &, B. Rus $, D. Neely*, C. Strangio^, M. Dunne + * STFC Rutherford Appleton Laboratory, Didcot, UK, & IPCF-CNR, Italy $ Academy of Science-PALS, Czech Republic, ^ENEA Frascati, Italy + presently, Lawrence Livermore National Laboratory (USA) (when summary sent STFC RAL,UK)

2 Compression Lasers Heating Targets: Fast Ignition Shock Ignition Original idea Manufacturing / Injection and Tracking CHAMBER DESIGN?? REPETITIVE OPERATION

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4 HiPER launched a program in studying conditions of CHAMBER DYNAMICS Physics and Technology for assessment of CHAMBER SAFETY AND TECHNOLOGY Laser, Target, Manufacturing, Injection Tracking, Repetitive operation This is Preparatory Phase NOW A NEXT STEP IS BEING PREPARE.

5 Independent Experiments to demonstrate REPETITIVE OPERATION to be INTEGRATED in the HiPER Construction CHAMBER TECHNOLOGY: understanding physics and propose DESIGNS for ENGINEERING FACILITY (HIPER 4A / BURST Mode) and next step of POWER PLANT (HIPER 4B) RISK REDUCTION

6 Ignition and burn (also LMJ)

7 FAST IGNITION FIREX OMEGA-EP PETAL NIF

8 The guidelines for confidence in arrival technologies on time are also based in: Targeting requirements are already obtained and also in other more difficult applications Injection and Tracking systems at the required level is on the way in different countries USA, Japan, and also in Europe Target Manufacturing at high repetition is progressing with new ideas and experimental verification, but also seeing other industrial fields As in any other Power Systems with upgraded efficiency can be envisioned through new Materials in Target, but also in Structural Materials to work at higher temperatures Cost reduction in Diodes is expected

9 DESIGN OF HIPER 4A Dimensioning First Wall analysis Safety and Radio- Protection

10 Road map for HiPER Chamber design Material Tungsten is the most reliable material for the first wall Good properties Many irradiation studies available (and more to come) It is planned for LIFE, FALCON-D, ITER (divertor) and DEMO (replacing Be) Other materials can be considered in the future but today it is certain that W will work. Structural material to be chosen based on activation and compatibility with W. Surrrounding structural Steels could be an option but also Carbon Fiber or SiC. Chamber Radius Dependent on the target Energy. A 50MJ target without gas protection requires a 5m radius chamber for repetitive experiments. Gas Protection HiPER 1st should work without gas no conflicts between Gas-Laser-Target injection Latest stages of HiPER should allow for experiments with gas Target Energy > 50MJ, gas needed -> HiPER 4b will have to work with gas -Critical relationship between Target Energy - Gas Pressure Chamber Radius -In the future those parameters will have to be chosen so that fluences on first wall do not surpass the limits already shown.

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12 Heat Flux parameter: Energy/m 2 / pulse duration (MJm -2 s ) Thermo-mechanical threat Melting MJm -2 s -0.5 Cracking 40 MJm -2 s -0.5 RHEPP-1 MK200-U QSPA Kh-50 Roughning JUDITH 20 MJm -2 s ,E+06 1,E+06 Heat P x Flux sqrt Parameter (t) / MW s0.5 MJ m-2 m s ,E+05 1,E+04 1,E+03 1,E+02 1,E+01 M R M M C B M C B - boiling M - melting C - cracking R - roughening 1,E+05 1,E+04 1,E+03 1,E+02 1,E+01 P / MW m-2 1,E+00 J. Linke et al, JNM (2007) ,E-07 1,E-05 1,E-03 1,E-01 1,E+01 IFE (laser fusion) pulse duration / s ELMs disruptions VDEs I T E R 1,E+00 pulse duration / s divertor HF

13 New experiments have proposed by DENIM(UPM) "Nano-Engineered" Tungsten helium retention experiments are encouraging Mass loss rate: high at first, slows afterwards 1.0 Mass loss rate (kg/day) 28 kg/fpy (< 1 µm solid) Sam Zenobia (Wisconsin) Actual exposure (He + /cm 2 ) (From kev = approx 5% total spectrum) Exposure Time (equivalent FPD)

14 The Role of the Spatial and Temporal Radiation Deposition in Inertial Fusion Chambers: The particular case of HiPER Thanks to J. Perkins (LLNL)

15 Proposed / Identified Experiments In order to study the combined effect of light species (D/He) and heavier ions (C) on first wall materials and final optics components subjected to IFE radiation conditions, one needs to use a multi-beam system. A proposal is running to use the double beam facility available at the group of Ion Physics in Forshcugzentrum Rossendorf. For the final optics, we will need to compare high quality optical graded silica samples with KU1 silica, well known for its radiation degradation resistance. In addition, we need to consider the performance of (unavoidable) anti-reflective coatings (e.g. hafnia) subjected to IFE ion irradiation. For this purpose a plan is proposed to reproduce the effects due to simultaneous implantation of C-He/D typical of an ICF reactor.

16 Proposed Experiments The implanted-induced effects of H, D and He as single light species in W have been widely studied. However, as far as we know, synergetic effects which may reduce significantly the operational window of W as a first wall material have been only reported for Magnetic Fusion (MF) conditions at room temperature. Moreover, the interaction with C poses additional risks on material performance. The work intend to carry out (in facilities such as Jannus or TIARA facilities) is related to the study of the combined effect of light species (D,3He) and heavier ions (12C) on first wall materials for IFE reactors. In particular, we will co-implant D, 3He and 12C in single- and poly-crystalline W samples. In order to simulate a prototypical IF energy ion, the implantation energies would be selected to be 0.75 MeV for 12C, 1.51 MeV for 3He and 0.5 MeV for D. The fluences used for implantation will range from 1x1015 to 1x1017 cm-2. The implantation would be done at different temperatures (from room temperature up to above 1000 ºC). These conditions are very similar to those expected for the first phases of HiPER. The effect of tritium is critical: work at Rossendorf and Katholike Universiteit Leuven (KUL) for diffusion and depth profiling characterization.

17 SAFETY AND RADIOPROTECTION OF HIPER 4A

18 Target Type Dry Wall Chamber Dry Wall Gas Protected Chamber (Xe density in the range 10-2 Wet Wall Chamber CI-ID Hohlraum? CI-DD Shell? FI Shell and Cone? SI Shell? Thinking in HiPER 4b Power Plant Start of Assessment: Target Survival depending on Protection

19 First Wall Material Survival (5 years 864,000 shots/day) Dry Wall Chamber Dry Wall Gas Protected Chamber (Xe density in the range 10-2 Wet Wall Chamber Tungsten wall and Indirect Drive The huge X-ray pulse makes difficult to keep R=5 m N/A Tungsten wall and Direct Drive To keep R=5 m, see comments 3 and 8, below To keep R=5 m, see comments 3 and 8, below N/A Wet Wall N/A N/A Thinking in HiPER 4b Power Plant Start of Assessment: First Wall Survival depending on Protection Wet wall due to its self-healing nature is perfect as first wall. 1.Dry wall chambers can always meet the requirements, it is a question of increasing the chamber dimensions, however, this is an undesired option. 2.Magnetic intervention has shown to work but it is not the best option due to complexity and cost. 3.The limiting factor for the use of W is He retention in radiation-induced cavities leading to blistering and material exfoliation. 4.Gas protection permits to mitigate the thermal loads keeping the first wall material below the threshold at which thermo-mechanical effects are fatal. For example, if W is used for first wall should not exceed 2400ºC. 5.However, due to incompatibilities with target injection, the gas pressure must be kept in the 10-2 mbar (tens of mtorr) range, much lower than needed for full ion mitigation. 6.Therefore, the most deleterious ions (alfa particles from fusion reactions) will practically not be attenuated. As a result, He retention is expected even with gas protection. 7.It is realistic to assume that R&D in new materials will give an optimal solution. The following points may be met by first wall materials: a.the thermal load must not harm the material. This implies to avoid excessive thermal load in the first µm of material. Instead the load must be deposited significantly deeper. This implies to design high area surfaces (needle-like). b.development of stable nano-structures is desirable because (i) they are less prone to vacancy clustering, (ii) they facilitate He release. c.the materials must be porous enough to facilitate the release of light species, in particular He. d.any candidate material must be studied under realistic IFE conditions for a sufficient number of cycles.

20 CONCLUSIONS HiPER Project will enter in a new phase where definition of Physics and Technology understanding of CHAMBER is CRITICAL, together with a realistic study of Blanket systems First Design has been made for repetitive operation in burst mode (not continuous), and study is progressing for Power Plant conditions. Developments in this Area MUST be fully consistent and parallel with advances in other systems (lasers, target, injection.) Synergism with Magnetic Fusion in some Areas has been highlighted

21 Posters this afternoong (Thrusday 14) IFE/P6-22 Juárez, R. Spain Overview on Neutronics, Safety and Radiological Protection of HiPER Facilty IFE/P6-23 Alvarez, J. Spain The Role of the Spatial and Temporal Radiation Deposition in Inertial Fusion Chambers IFE/P6-24 Cuesta-Lopez, S. Spain Modeling Advanced Materials for Nuclear Fusion Technology IFE/P6-25 Gonzalez-Arrabal, R. Spain Study of diffusion and retention of light species (H and He) in pure W and W-based materials