1. 1 ITPA-IOS meeting, October 2011J. Stober ITPA-IOS Meeting Kyoto 10/2011 Report from ASDEX Upgrade Reported by Jörg Stober for the AUG Team

2. 2 ITPA-IOS meeting, October 2011J. Stober Topics selected results of the last campaign, related to IOS - RMP-coils - N 2 -seeding : high power, q 95 = 3 - O1 heating of H-modes - improved H-mode (advanced inductive) Issues related to JE, not reported elsewhere 4.3 nu* scann: plans for next year 5.2 ICRH Next campaign: time line and hardware modifications

3. 3 ITPA-IOS meeting, October 2011J. Stober RMP-coils (Next slides from W. Suttrop, ITPA-PEP) Operation Jan - Jul 2011: 2×4 B-coils (upper and lower rows) n = 2 ELM mitigation n = 1 Error field measurement Shutdown Aug-Dec 2011 Installation of additional 8 upper/lower B-coils Operation Jan 2012 - n = 0, odd/even up/down parity n = 2, row phasing 0,90,180,270 degrees n = 4, odd/even up/down parity Power supplies: — Currently 2 circuits with grid-commutated 2-quadrant converters fmax 20 Hz. — Seeking solution for 4 independent 4-quadrant amplifiers (±1 kA into 500 μH) (n = 3, rotating fields) Full in-vessel coil set: 3 rows, each with 8 saddle coils W Suttrop et al, Fus. Eng. Des. 84 (2009) 209

4. 4 ITPA-IOS meeting, October 2011J. Stober RMP-coils : no ELMs triggered with pellet fuelling P. Lang

5. 5 ITPA-IOS meeting, October 2011J. Stober RMP-coils : central densities of 1.6 n GW selected

6. 6 ITPA-IOS meeting, October 2011J. Stober RMP-coils : no density dependence of  E

7. 7 ITPA-IOS meeting, October 2011J. Stober RMP-coils : DIII-D low- * mitigation not reproduced selected W.Suttrop, T.Evans

8. 8 ITPA-IOS meeting, October 2011J. Stober RMP-coils : comparison with DIII-D ongoing selected

9. 9 ITPA-IOS meeting, October 2011J. Stober RMP-coils : summary

10. 10 ITPA-IOS meeting, October 2011J. Stober High power seeding with peak heatload < 5 MW/m2 Peak load < 5 MW/m 2 ! Combined strong D divertor puff, feedback controlled N divertor seeding (q 95 =3.7,  u =0.1,  l =0.43) Modelling with B2-Eirene about to start IOS 1.2, A. Kallenbach

11. 11 ITPA-IOS meeting, October 2011J. Stober q 95 = 3 with N 2 seeding I p (MA) H-factor nene NN W mhd P ECRH,X3 TS core edge TeTe MP-coils snif T e,div N2N2 P NBI, P rad P tot D2D2 IR-Power Div o i #26870

12. 12 ITPA-IOS meeting, October 2011J. Stober O1-heating of H-modes : polarisation control 105 GHz B t = 3.2 T „wrong “ X-modedirectlyreflected O1 X1 X-mode cut-off 1 st harm Res

13. 13 ITPA-IOS meeting, October 2011J. Stober O1-heating of H-modes : polarisation control Power X-mode (%) 1 2 3 4 5 Sniffer signal (V) 0 2 4 6 8 10 1.52.02.5 time (s) 158  167  With 1% X-mode content, switch-off level is already exceeded (preliminary, orthogonal scan still to be done) H-mode, 1 MA, -3.2 T, 105 GHz, #26864

14. 14 ITPA-IOS meeting, October 2011J. Stober O1-heating of H-modes: effect of UHR V. Vdovin finds significant effect of UHR for O1 scenario with full wave code. Does he predict measurable effects for AUG ? These could be verified using modulated ECRH and X2-ECE. Preparation on AUG: finalize polarisation control such that X2-ECE can be used (up to 188 GHz) AUG-proposal submitted for 2012 co-authors: V. Vdovin, R. Prater

15. 15 ITPA-IOS meeting, October 2011J. Stober Access to improved H-mode (advanced inductive)

16. 16 ITPA-IOS meeting, October 2011J. Stober Improved H-mode: current overshoot selected (J. Hobirk, EPS 2011)

17. Pulse very similar Slightly less gas and lower target density for heating NBI heating increased to 10MW Small differences in density and power waveforms can lead to significant improvement on AUG β N =4.5 and confinement equivalent to H 98y2 >2 reached terminated by strong n=1 mode Extended ELM-free phase before crash Also radiation increases strongly before crash (Slide from EPS 2011 talk J. Hobirk)

18. 18 ITPA-IOS meeting, October 2011J. Stober Improved H-mode: recovery of the pre-W scheme #20993 : year 2006 ICRH limiters still graphite #27056 : year 2011 All tungsten ?? days after boronization Major differences - replace ICRH by ECRH - wave form gas puff Already quite close but ramp-up and H-factor not fully recovered I p n core n edge P tot P RF H98 W MHD  0,div  0,main D 2 puff T e0, T i0

19. 19 ITPA-IOS meeting, October 2011J. Stober IOS 4.3 : nu* scaling of advanced inductive Szenario No dedicated discharges in 2011: try to learn from rho* scan Scaling: I 2 = c I 1, B 2 = c B 1, T 2 = c 2 T 1, n 2 = n 1  * 2 = c -4 * 1 minimum sensible c = 1.2 yields factor 2 in * Problem (in AUG): n/n GW varies as 1/c, how wide can it be varied? Try to connect to rho* experiment (see C. Challis for JE 4.2), including attempts to rise density.

20. 20 ITPA-IOS meeting, October 2011J. Stober Gas puff scan in rho*-scan shape and q 95 rho*-scan lowest density attempt to increase density H98 W mhd I p Gas n core n edge H  P NBI P ECRH T e #27224#27052

21. 21 ITPA-IOS meeting, October 2011J. Stober Density profile can only be varied by 1.12 #27224 #27052 scaled both @ 2.6s So far, good match of shape

22. 22 ITPA-IOS meeting, October 2011J. Stober ECRH scheme used : compensated toroidal lauch p ECRH j ECCD

23. 23 ITPA-IOS meeting, October 2011J. Stober Torbeam: Poor absorption for n 2 = 1.15 n 1

24. 24 ITPA-IOS meeting, October 2011J. Stober Proposed solution: increase q 95, B t by 5% Allows smaller tor. injection angle, simulation with n = 1.2 n rho*

25. 25 ITPA-IOS meeting, October 2011J. Stober The high I p, B t case can be heated on low field side

26. 26 ITPA-IOS meeting, October 2011J. Stober Reasonable agreement of ECRH power deposition rho* case, #27224 q 95 = 4.2 B t = 2.26 T I p = 0.93 MA n e0 = 8.6 x 10 19 m -3 high * case q 95 = 4.4 B t = 2.37 T I p = 0.93 MA n e0 = 10.3 x 10 19 m -3 low * case q 95 = 4.4 B t = 2.85 T I p = 1.12 MA n e0 = 10.3 x 10 19 m -3

27. 27 ITPA-IOS meeting, October 2011J. Stober IOS-4.3 : AUG-Proposal for 2012 - repeat rho* pulse with 5% higher B t and modified ECRH angles - increase density by 20% - increase B t and I p by 20% - adjust gas puff and power to match scaling requirements 5-10 shots depending on number of iterations May still be modified after this meeting

28. 28 ITPA-IOS meeting, October 2011J. Stober IOS-5.2 : ICRH gas puff Old results: if gas injected locally, antenna loading is significantly higher (doubled in our case) [Ph. Jacquet, V. Bobkov et al., to be submitted to NF] No experiments done in 2011: restrictions in infrastructure of antenna gas injection which was transfered to another antenna Increase of AUG ICRF antenna loading by local gas injection 2012: new infrastructure, measure the local effect in large type I-ELMy plasmas, check loading depence on RF power at low power V. Bobkov

29. 29 ITPA-IOS meeting, October 2011J. Stober AUG : Hardware upgrades and time line 2012 - Number of RMP coils doubled, allows n=4 perturbation - Power supplies to rotate perturbation delayed (no pref. funding) - Design of 8 mid-plane coils ready, but no preferential EU funding - Limiters of ICRH antenae will be partially boron-coated - New antenna design with reduced stray field ready, Financing unclear, coop with Italy and/or China - 1 additional ECRH unit (1 MW) in spring 2012 Total power in plasma at 140 GHz close to 5 MW Restart January 2012 End of campaignNovember 2012 6 weeks without operation in August / September

30. 30 ITPA-IOS meeting, October 2011J. Stober AUG : ICRH Upgrades After 2012: two new 3-strap antennas for better compatibility with W wall 2012: two antennas with B-coated side limiters to make operation easier (V. Bobkov et al.)