1. 1E. TsitronePWI TF meeting 17-19/10/2005 Euratom Plasma Wall Interactions : Tore Supra recent results E. Tsitrone for Tore Supra team With special thanks to : M. Bécoulet, C. Brosset, J. Bucalossi, L. Colas, Y. Corre, A. Ekedhal, J. L. Gardarein, P. Ghendrih, C. Grisolia, A. Grosman, J. Gunn, T. Loarer, P. Monier Garbet, M. Missirlian, R. Mitteau, I. Nanobashvili, B. Pégourié, P. Tamain Outline : SOL physics C migration / D retention Heat flux deposition and IR imaging Prospects

2. 2E. TsitronePWI TF meeting 17-19/10/2005 Euratom SOL Physics (a tribute to Langmuir probes)

3. 3E. TsitronePWI TF meeting 17-19/10/2005 Euratom Understanding SOL flows Particle outflux concentrated on LFS M // towards HFS (M // ~0.5 90 % of source on LFS) Strong flows at the top of the machine : universal feature in tokamaks (JET, TS) Particle outflux uniform poloidally M // ~0 J. Gunn, International conference plasma 2005, 6-9/09/2005, Poland M // = 1M // = -1 M // ~0 M // < 0 M // ~0 M // = -1 M // = 1

4. 4E. TsitronePWI TF meeting 17-19/10/2005 Euratom From modelling to experiments … Plasma ejected from a region around equatorial plane on LFS (narrow poloidal extent ?) J. Gunn, International conference plasma 2005, 6-9/09/2005, Poland Influences SOL thickness : Thin SOL (decay length ~ 3 cm) if this region is obstructed (plasma on LFS) Thick SOL (decay length up to 20 cm) otherwise (plasma on HFS) Thin SOL Thick SOL M // to HFS Reduced M // M // to LFS

5. 5E. TsitronePWI TF meeting 17-19/10/2005 Euratom Turbulent transport in the SOL Fast acquisition mode on the mobile Langmuir probe (1 s) : signal more bursty in the far SOL I. Nanobashvili et al, proposal for PSI 2006 3D modelling of the SOL under developpment : transport + turbulence P. Tamain et al, proposal for PSI 2006 Close to LCFS : pdf ~ gaussian Far SOL : pdf strongly non gaussian

6. 6E. TsitronePWI TF meeting 17-19/10/2005 Euratom ELMs suppression by ergodization DIIID : ELMs suppression w/o confinement degradation over a wide range of pedestal parameters. Easier at low * => good news for ITER Requirements for idealergodic coils: 1)As close as possible to plasma (minimize I coil, ) 2) Perturbation resonant at the edge but not in the plasma centre (no NTMs seed islands!) 3) Poloidal spectrum sufficiently large to cover all scenarios (q=3-5: ITB, Hybrid, standard H- mode …) => Design of ergodisation coils for ITER underway (EFDA task), to be tested in JET ? M. Bécoulet et al, EPS 2005 Main difficulties: No space both on JET and ITER External coils => far from plasma => large currents! ( ~ 200 kA for JET, ~ 400 kA for ITER)

7. 7E. TsitronePWI TF meeting 17-19/10/2005 Euratom C migration / D retention (the quest for the missing D)

8. 8E. TsitronePWI TF meeting 17-19/10/2005 Euratom D retention in TS : overview Balance on 1 campaign (~ 20 000 s) : D inventory from particle balance (~ 10 23 D) D recovery : after shot : ~ 10 21 D (He glow : ~ 10 22 D, disruptions : up to ~ 5 10 22 D) D retention rate ~ 10 20 D/s (50 % injection, few % recycling flux) depends : little of ne, fuelling method NOT on P ICRH on P LH (fast e- ? ) D retention rate [Pa.m 3 /s] nl = 3.6-4.0 10 19 m -2 nl = 2.5-2.6 10 19 m -2 LHCD power [MW] 01234 0.2 0.3 0.4 0.5 0.6 0.7 ICRH =2-4 MW [J. Bucalossi et al., EPS 2005] Balance on 1 day : ~ 0 if short pulses ( > 0 if long pulses (> 100 s) >> D inventory from post mortem analysis (~ 10 22 D) D balance not closed ! In 2005 long pulse scenario extended to higher power/density : GJA : LH =3 MW, nl = 2.5 3 MW, 6.18 mn, 1.07 GJ LH + ICRH =3+4 MW, nl = 3.8 - 5 7 MW, 1 mn, 0.42 GJ

9. 9E. TsitronePWI TF meeting 17-19/10/2005 Euratom Progress on carbon balance in TS Total : 2.7-5.5 g/h Neutralisers : 1-2 g/h Obstacles in SOL : 0.5 g/h Carbon balance ~ coherent BUT carbon source (~ 10 20 C/s ) ~ D retention rate (~ 10 20 D/s ) : not sufficient if codeposition only with D/C ratio ~ 1-10 % TPL Out. lim + RF ant. Bumpers Carbon source : Toroidal Pump Limiter (TPL) Gross erosion from CII spectroscopy : 10 (GJA) to 30 (GJB) g/h from calculation (GJA) : 41 g/h E. Dufour et al. EPS 2005 E. Tsitrone et al. IAEA 2004 Net erosion from TPL erosion measurements, averaged over 4 campaigns : 7 g/h (max net erosion rates 2-4 nm/s) from calculation : 5.2 g/h (90% local redeposition) C. Lowry, private communication from mass spectrometer : Pumped out : 0.2-2 g/h C.Brosset, private communication Carbon sinks from analysed samples : TPL (deposition zones) : 1 g/h C.Brosset et al., PSI 2004, TCM SSO 2005 Other retention mechanisms (bulk diffusion in CFC ?)

10. 10E. TsitronePWI TF meeting 17-19/10/2005 Euratom Heat flux deposition and IR imaging (High Tsurf = danger ?)

11. 11E. TsitronePWI TF meeting 17-19/10/2005 Euratom RF heating generates fast particles Top / bottom asymmetry : Local : on each waveguide (interaction wave/plasma) Global : E x B drift Left/right asymmetry : fast ions generated by ICRH (reverses with Ip/Bt) NB : large orbit losses significant in TS (not a pb for ITER) B, I P Fast Ions 33894 A. Ekedahl et al, proposal for PSI 2006 e - beams accelerated in LH near field Convected power ICRH specific hot spots ICRH antenna at 60s ICRH: 4MW LH : 3MW L. Colas et al

12. 12E. TsitronePWI TF meeting 17-19/10/2005 Euratom Heat flux deposition simulation Interpreting IR imaging Hot zones Strong heat flux Low heat flux (C deposits) Cold zone Automatic tool for analysis (monitoring C deposits growth ?) and safety applications IR imaging Net erosion zones : deposits in gaps Net redep zones : deposits on tile surface

13. 13E. TsitronePWI TF meeting 17-19/10/2005 Euratom Interpreting IR imaging 2D model is necessary for valid deconvolution of IR temperature (to be tested on TS and JET data) JL Gardarein, Y. Corre et al, proposal for PSI 2006

14. 14E. TsitronePWI TF meeting 17-19/10/2005 Euratom Prospects PWI program focussed along 4 projects : SOL physics (contact person : P. Ghendrih) C migration / D retention (contact person : E. Tsitrone) IR imaging (contact person : JM Travère) Conditionning and detritiation (contact person : C. Grisolia) TS midterm program workshop + external scientific concil : SOL transport and turbulence C material issues : (in)validate C for ITER (C erosion, D retention, detritiation …) Open for collaboration !

15. 15E. TsitronePWI TF meeting 17-19/10/2005 Euratom Prospects SOL physics More probes to come (RFA, tunnel …) : SOL Ti measurements Synergy between theory and experiment : can simulations quantitatively explain experimental SOL flows ? F. Onofri, IUSTI, to be presented in EFDA workshop on dust Conditionning and detritiation Characterization of conditionning (boronisation, glow …) Detritiation : laser implemented on AIA (+ LIBS) Dust : diagnostic (safety) IR imaging Implement up to date image processing techniques to IR data (physics + safety) C migration / D retention Extend long pulses to lower Te conditions (high ne / impurity injection) Solve inconsistency between particle balance / D inventory in TS Explore bulk diffusion joined TS / PISCES experiment (ITPA) : exposure of CFC samples to high D fluence