Association EuratomCea TORE SUPRA Integration of High Power

Association Euratom-Cea TORE SUPRA Integration of High Power, Long Pulse Operation in Tore Supra in preparation of ITER M. Chatelier, on behalf of Equipe Tore Supra TORE SUPRA 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 1

Association Euratom-Cea TORE SUPRA Tore Supra, large superconducting tokamak devoted to long-duration, high performance discharges • 3 rd largest tokamak • Operation of the cryomagnetic system for 18 years • All PFCs actively cooled • 6 min discharges (2003) with 1 GJ injected/exhausted energy LHCD Power (MW) Transformer flux (Wb) Te(0) (ke. V) Line averaged density (x 1019 m-2) Ti(0) (ke. V) Neutron (x 1010/s) ] PLHCD = 3 MW ] Ip = 0. 5 MA ] ne 0 = 2. 5 1019 m-3 21 st IAEA Fusion Energy Conference, Chengdu Zeff M. Chatelier 17 October 2006 2

Association Euratom-Cea TORE SUPRA Large margin towards higher power long discharges • Convective losses routinely handled by the TPL (3 -5 MWm-2) • H/CD systems initially designed for 30 sec operation; ongoing upgrade (see Beaumont et al. , IT/2 -5) ] towards 10 -12 MW for 1000 sec, near Greenwald • Tore Supra current program: Injected power 9. 5 MW 21 st IAEA Fusion Energy Conference, Chengdu ] Investigation NI discharges ] Preparation scenarios & techniques for high power long pulse operation (based on LHCD & ICRH) M. Chatelier 17 October 2006 3

Association Euratom-Cea Tore Supra CIMES project (2008, continous Current drive) 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier TORE SUPRA CIEL project (2003, active cooling) 17 October 2006 4

Association Euratom-Cea TORE SUPRA Outline • Safely operating Tore Supra at multi-MW level • Multi-MW long duration discharges results • Integrating operational controls for steady-state scenarios • Turbulence measurements and local transport analysis • Plasma wall interaction during long discharge operation • Technological developments for long discharge operation follow-up • Conclusions and prospects 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 5

Association Euratom-Cea TORE SUPRA Safely operating Tore Supra at multi-MW level 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 6

Association Euratom-Cea TORE SUPRA 10 MW in TS representative of ITER operation in term of averaged power density & heat exhaust ITER Pinj / Vol (0. 43 MWm-3) Pinj / Surf (0. 16 MWm-2) Pinj / R 0 (4. 4 MWm-1) Pnom 360 MW Power density 130 MW Radiated power 30 MW Convected power 150 MW (100 ) 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 7

Association Euratom-Cea TORE SUPRA Handling localized heat loads • LHCD launcher • ICRH antenna ] A: fast electrons ] B: fast ion direct losses ] C: Arcing ] A: fast electrons ] B: fast ion direct losses ] C: Rectified sheath A (1000°) C (800°) A(800°) C A(800°) B(600°) B (800°) B’ (1000°) (see Goniche et al. EX/P 6 -12) 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 8

Association Euratom-Cea TORE SUPRA Safely operating Tore Supra at 10 MW level • 20 areas monitored delivering Real Time IR signals • Each used in RT controller with specific safety strategy LHCD launcher zone B 21 st IAEA Fusion Energy Conference, Chengdu LHCD launcher zone A M. Chatelier 17 October 2006 9

Association Euratom-Cea TORE SUPRA Multi-MW long duration discharges results 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 10

Association Euratom-Cea TORE SUPRA Significant ion heating at high Greenwald fraction • Ip = 0. 9 MA; ne 0 = 5 1019 m-3; 8. 4 MW H/D minority #33612 • Ti close to Te • HITER-L = 1. 3 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 11

Association Euratom-Cea TORE SUPRA Toroidal rotation observed with ICRH • Suggests sheared rotation • Could explain confinement improvement through ITG and TE modes stabilization (Kinezero) 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 12

Association Euratom-Cea TORE SUPRA Long sawteeth-free discharges with ICRH & LHCD • Ip = 0. 6 MA; ne 0 = 4 1019 m-3; q(0) above 1 #33898 • Reminiscent of hybrid Ptot scenarios, but q profile PICH = 6. 3 MW controlled by LHCD PLH = 3. 1 MW Greenwald fract. = 0. 93 b. N = 0. 83 q(0) non-inductive fract. ~ 50% 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 13

Association Euratom-Cea TORE SUPRA Integrating operational controls for steady-state scenarios 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 14

Association Euratom-Cea TORE SUPRA Optimising plasma performance reliability #36133 • Fully NI long discharges prone to MHD activity • Small MHD free operating window (see Maget et al. EX/P 8 -21) • RT current profile control: ] Actuator LHCD n// ] Sensor HXR width • Combined with control of: ] Ip (LHCD power) ] Flux consumption (primary) • Triple control at low loop voltage (< 10 m. V) (see Joffrin et al. , EX/1 -6) 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 15

Association Euratom-Cea TORE SUPRA Integrating plasma optimisation and safe operation • RT IR safety + triple control • Discharges 70 sec / 7 MW controlled in MHD free window • Pioneers integration work for ITER when combining: ] global performance ] profile shaping ] plasma stability ] PFCs protection 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 16

Association Euratom-Cea TORE SUPRA Turbulence measurements and local transport analysis 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 17

Association Euratom-Cea TORE SUPRA Neoclassical level pinch observed inside q=1 in plasma • Progressive density build-up during sawtooth recovery • Inward pinch 0. 1 ms-1 Ware pinch • Low diffusion 0. 1 ms-2 coherent with low ñ level • Vanishes with high CD and/or heating power see Hennequin et al. , EX/P 4 -36 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 18

Association Euratom-Cea TORE SUPRA scaling experiments in L mode Supported by density fluctuation measurements • Two sets of discharges n= 0. 5 / BT= 3. 8 T & n= 0. 2 / BT= 3. 2 T with matched *, * & q profiles • Weak degradation. exponent: ] Global confinement ] Effective diffusivity ] ITER L-mode scaling -0. 2 0. 15 -0. 2 0. 4 -1. 4 • Supported by density fluctuation measurements • Bias in extraction of dimensionless scaling law extraction? 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 19

Association Euratom-Cea TORE SUPRA Plasma wall interaction issues during long discharge operation 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 20

Association Euratom-Cea TORE SUPRA Fuel retention in Carbon walls D retention rate (D/s) • Long term constant retention rate observed (50 -80% injected flux) • Repetitive behaviour on 3 consecutive shots (15 min) D/C = 0. 1 Mechanism Type of retention Saturat. Adsorption in C porosity Transient Yes Implantation Permanent Yes Codeposition Permanent No Bulk diffusion & trapping Permanent No 17 October 2006 21 Time (s) 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier

Association Euratom-Cea TORE SUPRA Bulk diffusion, a credible retention mechanism • Evidenced in laboratory experiments at high fluence (fl) • Key parameter: exposure time • Retained fraction (fluence)0. 5 D retention rate (D/s) • Simple model: implantation up to saturation + evolution retained fraction (fluence)0. 5 • Needs to be refined • Extrapolation to ITER: D/C = 0. 1 Time (s) 21 st IAEA Fusion Energy Conference, Chengdu ] Bulk diff. possible, but fl 0. 5 ] Codeposition ( fl) still major concern ] Detritiation difficult for both M. Chatelier 17 October 2006 22

Association Euratom-Cea TORE SUPRA Flows in the SOL: a common physics for divertor and limiter machine • Half recycling at each strike zone + uniform radial outflux from core => nearly stagnant flow at Mach probe 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 23

Association Euratom-Cea TORE SUPRA Evidence of strong outflux across the outboard midplane HFS BOT LFS TOP Uniform outflux < 0 0 > 0 Localized outflux < 0 0 > 0 Measured < 0 0 > 0 • Large SOL width when unobstructed by outboard limiter • SOL fed by long range parallel bursty transport events located near the outboard midplane (see Gunn et al. , EX/P 4 -9) 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 24

Association Euratom-Cea TORE SUPRA Technological developments for long discharge operation follow-up 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 25

Association Euratom-Cea TORE SUPRA Articulated Inspection Arm operational in 2007 • In vessel remote handling light payload carrier (10 kg) ] able to reach all part of TS chamber without breaking vacuum • 8 -meter long, 5 modules with 2 actuated joints each • Prototype module tested under ITER representative vacuum and temperature condition • Various use: ] High definition CCD for inspection ] Leak testing tool ] Laser ablation tool for surface characterization and codeposited layer removal (see Semerok et al. , IT/P 1 -15)…. 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 26

Association Euratom-Cea TORE SUPRA Conclusions and … • After 3 MW/LH 6 mn discharges of 2003, Tore Supra has performed high power long pulse discharges (5 -10 MW, 20 -60 s) still far from the limits of the actively cooled pump limiter • Substantial progress in real time control of safe HF -non inductively driven and heated - discharges: ] Minority ICRH & LH driven steady state discharges ] Real time control of antennas temperature ] Real time control of current profile • Extensive density fluctuation measurements bring coherence in transport and stability studies • Large and continuous D absorption by the C wall suggesting large bulk diffusion process at work • Edge particle radial transport primarily on the outboard side consistently with Langmuir probe measurements 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 27

Association Euratom-Cea … Prospects TORE SUPRA • Enhancement of the LH power & duration in preparation (CIMES project: 6 -8 MW, 1000 s) ] Steady state high power non inductive real time controlled discharges ] Physics of non inductive discharges • Preparation of articulated inspection arm for several purposes ] Visual inspection of PFCs ] Vacuum leak test ] D recovery … under real conditions of temperature/vacuum • Pursue building experience in integrating ITER relevant constraints for high power operation in actively cooled environment Complementary of JET (& ASDEX-U) with all metal wall and high NBI 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 28

Association Euratom-Cea TORE SUPRA • Monday 16 th ] E. Joffrin et al. , EX/1 -6 • Tuesday 17 th ] Semerok et al. , IT/P 1 -15 ] Garbet et al. , TH 2 -2, Beyond scale separation in gyrokinetic turbulence ] Bécoulet M. et al. , IT/P 1 -29, Modelling of edge control by ergodic fields in DIII-D, JET and ITER • Wednesday 18 th ] Durocher et al. , FT/1 -5 • Thursday 19 th ] Hogan et al. , EX/P 4 -8, Mechanisms for carbon migration and deuterium retention in Tore Supra CIEL long discharges ] Gunn et al. , EX/P 4 -9 ] Hennequin et al. , EX/P 4 -36 • Friday 20 th ] Goniche et al. EX/P 6 -12 • Saturday 21 th ] Libeyre et al. , IT/2 -1 Ra, Remaining issues in superconducting magnets for ITER and associated R&D ] Beaumont et al. , IT/2 -5 ] Huysmans et al. , TH/P 8 -2, MHD stability in X-point geometry : simulation of ELMs ] Maget et al. EX/P 8 -21 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 29

Association Euratom-Cea TORE SUPRA Discriminating spurious overheated zones T (°C) • High temperature measured on poorly adherent objects • Identified by follow-up of reference discharges • Spurious zones excluded from monitored area #37421 #37193 #36970 #36854 B 4 C flakes T 200°C ICRH Q 5 Q 1 Q 2 time (s) 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 30

Association Euratom-Cea TORE SUPRA [H. Atsumi et al. , JNM 313 -316 (2003)] Permeation Molecular through “diffusion” open pores Transient retention (Phase 1) Trapping sites Long term retention (long pulse / high flux) 21 st IAEA Fusion Energy Conference, Chengdu M. Chatelier 17 October 2006 31