1. Darren McDonald, TFS1 meeting, 20th April 2006 1/20 Proposed JET 2006 confinement experiments D C McDonald Structure of talk: Hybrid studies ELMy H-mode, multi-machine gyro-radius scan ELMy H-mode, collisionality scan

2. Darren McDonald, TFS1 meeting, 20th April 2006 2/20 Hybrid confinement scaling D C McDonald, E Joffrin, T Luce, ….

3. Darren McDonald, TFS1 meeting, 20th April 2006 3/20 JET 2003-4 studies: plasmas with  N =2-2.7 H98(y,2) increases with Beta Indicates an improved confinement regime, or a problem with scaling at high  N Absolute values of H98≈1-1.2, lower than DIII-D/AUG Difficult to extrapolate to ITER JET 2003-4 experiments Joffrin, IAEA (2004)

4. Darren McDonald, TFS1 meeting, 20th April 2006 4/20 JET to perform further Hybrid studies (>10 sessions) in 2006 – Ascertain that mode is comparable with DIII-D/AUG mode – Document mode – including confinement behaviour JET to contribute 2003-4 and 2006 Hybrid data to the global and profile databases With data from other machines this should enable an assessment of the Hybrid confinement scaling – Is it appropriate to take ELMy H-mode scalings? – Can a separate Hybrid scaling be determined Part of the JET programme involves a Beta scan study – BetaN = 1.5 – 3, does confinement follow ELMy H-mode trend? Aims for 2006

5. 5/20 D. C. McDonald et al, S1-1.303 gyroradius scaling, JET, 19th April 2006 CDB-8: Gyro-radius scaling D C McDonald, C Petty, A Staebler, M Greenwald, C Giroud, I Nunes, G Maddison, H Leggate, I Voitsekhovitch, L Laborde

6. 6/20 D. C. McDonald et al, S1-1.303 gyroradius scaling, JET, 19th April 2006 2003 – 4 JET experiments Type I and Type III scans I p = 1.3 - 4.3MA close to gyro-Bohm Confirmed Gyro- radius scalings at most ITER-like conditions Error bars still large JET shots have 2-3 times ITER rho*, so 0.5 error translates to a 40% error for ITER Type III ELMy H-modes McDonald, IAEA (2004)

7. 7/20 D. C. McDonald et al, S1-1.303 gyroradius scaling, JET, 19th April 2006 DIII-D experiments: local transport DIII-D studies permitted local transport analysis which also found close to gyro- Bohm-like scaling Error bars still large large radial variation systematic errors momentum mismatch Turbulence L-mode studies show gBohm bhvr, but Bohm-like transport Petty, FS&T (2005) 978 McKee, NF (2001) 1235; Hennequin, PPCF (2004) B121

8. 8/20 D. C. McDonald et al, S1-1.303 gyroradius scaling, JET, 19th April 2006 For ELMy H-modes: DIII-D and JET both matched *= * ITER and  =  ITER In this way the extrapolation to ITER was in one parameter  *  1996 experiment with DIII-D © Blur-vision Result independently validated ITER prediction (figure) Individual machine scans were pretty narrow No turbulence, impurity or pedestal studies Aim: to improve these experiments to provide better ITER estimate and scaling for transport and turbulence ITER Physics Basis (OLD ITER)

9. 9/20 D. C. McDonald et al, S1-1.303 gyroradius scaling, JET, 19th April 2006 2006 experimental proposal Produce a multi-machine scan in Gyro-radius at matched (shape, q,  N, *) in ITER relevant conditions JET/DIII-D/AUG/C-Mod involved Machine constraints mean we have opted for q 95 =3.85, betaN=1.5 Start with JET/C-Mod match with DIII-D and AUG to add central points after this data is analysed C-Mod has time scheduled for April-May 2006 Plasmas must be well diagnosed for core, edge, fluctuations and impurity transport. Analysis includes: scaling, particle and thermal transport studies

10. 10/20 D. C. McDonald et al, S1-1.303 gyroradius scaling, JET, 19th April 2006 Proposed shape Use JET/AUG/C-Mod shape developed by I Nunes Same as for G Maddison’s experiments Match is clearly good and comparable with previous JET/DIII-D/AUG/C-Mod experiments

11. 11/20 D. C. McDonald et al, S1-1.303 gyroradius scaling, JET, 19th April 2006 Proposed matched parameters Parameter C-Mod (A) C-Mod (B) C-Mod (C) JET (A) JET (B)JET (C) Trans. Freq. (MHz)805080 R (m)0.675 2.90 a (m)0.220.220 0.945 B (T)5.33.32.62.581.720.86 I (MA)1.10.680.542.301.530.77 n (1E19 m^-3)31.516.712.27.424.321.71 P_gB (MW)5.803.612.855.853.901.95 W (MJ)0.2320.0900.0564.361.940.48 TAU_gB (s)0.0400.0250.0200.740.500.25 R/a3.07 kappa1.7 delta0.45 q_953.85 BETA_N1.30 nu*7.2 B*TAU_gB0.2120.0820.0511.9220.8540.214 F_GDL0.440.370.340.910.790.63 rho*3.444.715.530.380.500.80

12. 12/20 D. C. McDonald et al, S1-1.303 gyroradius scaling, JET, 19th April 2006 JET shot list 0.77 MA / 0.86 T, q95=3.85 shot. Tune gas and heating (≈2.0MW) to match BetaN = 1.3 and target density 1.53 MA / 1.72 T shot. Tune for same match (≈3.9MW) 2.58 MA / 2.3 T shot. Tune for same match (≈5.9MW) All plasmas must be well diagnosed: core and pedestal, impurity transport, turbulence, bolometry NBI / ICRH heating schemes Scheduled: June 2006 (test shots in May)

13. Darren McDonald, TFS1 meeting, 9th June 200513/20 Collisionality scan for core and edge transport D C McDonald, Geoff Cordey, Xavier Garbet, Paola Mantica, Carine Giroud, Irina Voitsekhovitch, Huw Leggate, Alberto Loarte

14. Darren McDonald, TFS1 meeting, 9th June 200514/20 Background: * scans A * scan experiment varies * at fixed (  *, , q, shape, heating...) In practise, it’s a field scan with I  B, n  B 0, T  B 2 Two previous scans on JET 1996 - B.  E  * - 0.27, 2 point, limited profile data 2004 - B.  E  * - 0.35, * - 0.50, 4 point, weak data (low I p, n e ) McDonald et al., IAEA (2004)

15. Darren McDonald, TFS1 meeting, 9th June 200515/20 * dependence a power law? All * scan experiments show a negative B  E - * correlation Power law fits show a variety of exponents General trend for weaker exponent at smaller *  not a simple power law Theoretically: could represent a transition between transport regimes Leggate et al., EPS (2005) p: -Ve exponent of * scaling B  E  * - p

16. Darren McDonald, TFS1 meeting, 9th June 200516/20 What do transport theorists say? Connor et al., PPCF (1988); Garbet et al., EPS (2004); Model ( B.  E  * p exponent) Dissipative TEM (1, 4/3, 2) Dissipative TIM (1) Collisionless TEM (0) Collisionless ITG Mode (0) Resistive ballooning (edge only) Zonal flows (neoclassically damped) B.  E  * p exponent 1, 4/3, 2 1 0 - Ve Leading candidate is kinetic drift wave turbulence with zonal flows, neo-classically damping

17. Darren McDonald, TFS1 meeting, 9th June 200517/20 Particle transport * is a key parameter for particle transport Previous results indicate a *- peaking correlation – This experiment will largely just add to the DB – Improved TS and EFIT data is of interest here – strong n e peaking will complicate analysis of main experiment He, Ni/Mo, Ne/Ar, will be performed simultaneously Weisen et al., EPS (2004)

18. Darren McDonald, TFS1 meeting, 9th June 200518/20 ELM energy loss Previous experiments show a falling  W ELM /W ped with increasing * Will collect edge data, so can study the * here Should benefit from improved edge data Loarte et al., PPCF 45 (2003) 1549

19. Darren McDonald, TFS1 meeting, 9th June 200519/20 Aims of experiment Experiment: 3 point * scan, from *  0.1 (collisionless) to * > 1 (collisional) – Good match of (  *, , q, shape, heating...) essential – Collect core and edge kinetic data, MSE, CX, IR camera Analysis – Analyse discharges for energy (TRANSP), bulk particle (TRANSP) and impurity (UTC-SANCO) transport as well as documenting ELM losses. – Test a series of models for energy, bulk particle and impurity transport. Scheduled: Aug 2006

20. Darren McDonald, TFS1 meeting, 9th June 200520/20 Pulse list (all same shape) 2.5 MA / 2.6 T, P NBI = 12 - 14 MW, unfueled: obtain low * (0.1) reference, based on #52010. Short gas scan 1.8 MA / 1.8 T, P NBI = 10 MW : mid * (0.4), tune power to match  N of reference Gas scan to match  * 1.3 MA / 1.3 T, P NBI = 8 MW : high * (1.4), tune power to match  N of reference Gas scan to match  * 3 shots 2 shots 3 shots 2 shots NB: wall loading should help us maintain density