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1 ITPA-IOS meeting, October 2011 J. Stober
ITPA-IOS Meeting Kyoto 10/2011Report from ASDEX Upgrade
Reported by Jörg Stober for the AUG Team
2 ITPA-IOS meeting, October 2011 J. Stober
Topics
selected results of the last campaign, related to IOS- RMP-coils
- N2-seeding : high power, q95 = 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 ITPA-IOS meeting, October 2011 J. 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 mitigationn = 1 Error field measurement
Shutdown Aug-Dec 2011Installation of additional 8 upper/lower B-coils
Operation Jan 2012 -n = 0, odd/even up/down parityn = 2, row phasing 0,90,180,270 degreesn = 4, odd/even up/down parity
Power supplies:— Currently 2 circuits with grid-commutated2-quadrant converters fmax 20 Hz.— Seeking solution for 4 independent4-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 ITPA-IOS meeting, October 2011 J. Stober
RMP-coils : no ELMs triggered with pellet fuelling
P. Lang
5 ITPA-IOS meeting, October 2011 J. Stober
RMP-coils : central densities of 1.6 nGW
selected
6 ITPA-IOS meeting, October 2011 J. Stober
RMP-coils : no density dependence of E
7 ITPA-IOS meeting, October 2011 J. Stober
RMP-coils : DIII-D low-* mitigation not reproduced
selected
W.Suttrop, T.Evans
8 ITPA-IOS meeting, October 2011 J. Stober
RMP-coils : comparison with DIII-D ongoing
selected
9 ITPA-IOS meeting, October 2011 J. Stober
RMP-coils : summary
10 ITPA-IOS meeting, October 2011 J. Stober
High power seeding with peak heatload < 5 MW/m2High power seeding with peak heatload < 5 MW/m2
Peak load < 5 MW/m2 !
Combined strong D divertor puff, feedback controlled N divertor seeding (q95=3.7, u=0.1, l=0.43)Modelling with B2-Eirene about to start
IOS 1.2, A. Kallenbach
11 ITPA-IOS meeting, October 2011 J. Stober
q95 = 3 with N2 seeding
Ip (MA)
H-factor
ne
N
Wmhd
PECRH,X3
TS
core
edge
Te
MP-coils
snif
Te,div
N2
PNBI, Prad
Ptot
D2
IR-Power Div o i
#26870
12 ITPA-IOS meeting, October 2011 J. Stober
O1-heating of H-modes : polarisation control
105 105 GHzGHzBBtt= 3.2 = 3.2 TT
„„wrongwrong““X-modeX-modedirectlydirectlyreflectereflectedd
O1 X1
X-modecut-off
1st harmRes
13 ITPA-IOS meeting, October 2011 J. Stober
O1-heating of H-modes : polarisation control
150
160
170
50 60 70 80
Power X-mode
2 %
4 %
/ 8
/ 4
0
2
4
6
8
160 165 170
Power X-mode (%)
1
2
3
4
5Sniffer signal (V)
0
2
4
6
8
10
1.5 2.0 2.5
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 ITPA-IOS meeting, October 2011 J. Stober
O1-heating of H-modes: effect of UHR
V. Vdovin finds significant effect of UHR for O1 scenariowith 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 thatX2-ECE can be used (up to 188 GHz)
AUG-proposal submitted for 2012co-authors: V. Vdovin, R. Prater
15 ITPA-IOS meeting, October 2011 J. Stober
Access to improved H-mode (advanced inductive)
16 ITPA-IOS meeting, October 2011 J. Stober
Improved H-mode: current overshoot
selected
(J. Hobirk, EPS 2011)
Pulse very similar Slightly less gas and lowertarget density for heating NBI heating increased to 10MW
Small differences in density and power waveforms can lead to significant improvement on AUG
βN=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 ITPA-IOS meeting, October 2011 J. Stober
Improved H-mode: recovery of the pre-W scheme
#20993 : year 2006ICRH limiters still graphite
#27056 : year 2011All tungsten?? days after boronization
Major differences- replace ICRH by ECRH- wave form gas puff
Already quite close butramp-up and H-factornot fully recovered
Ip
ncore
nedge
Ptot
PRF
H98
WMHD
0,div
0,main
D2 puff
Te0, Ti0
19 ITPA-IOS meeting, October 2011 J. Stober
IOS 4.3 : nu* scaling of advanced inductive Szenario
No dedicated discharges in 2011: try to learn from rho* scan
Scaling: I2 = c I1, B2 = c B1, T2 = c2 T1, n2 = n1 *2 = c -4 *1
minimum sensible c = 1.2 yields factor 2 in *
Problem (in AUG): n/nGW 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 ITPA-IOS meeting, October 2011 J. Stober
Gas puff scan in rho*-scan shape and q95
rho*-scan lowest density attempt to increase density
H98Wmhd
Ip
Gas
ncore
nedge
H
PNBI
PECRH
Te#27224 #27052
21 ITPA-IOS meeting, October 2011 J. Stober
Density profile can only be varied by 1.12
#27224
#27052scaled
both @ 2.6s
So far, good match of shape
22 ITPA-IOS meeting, October 2011 J. Stober
ECRH scheme used : compensated toroidal lauch
pECRH
jECCD
23 ITPA-IOS meeting, October 2011 J. Stober
Torbeam: Poor absorption for n2 = 1.15 n1
24 ITPA-IOS meeting, October 2011 J. Stober
Proposed solution: increase q95, Bt by 5%
Allows smaller tor. injection angle, simulation with n = 1.2 nrho*
25 ITPA-IOS meeting, October 2011 J. Stober
The high Ip, Bt case can be heated on low field side
26 ITPA-IOS meeting, October 2011 J. Stober
Reasonable agreement of ECRH power deposition
rho* case, #27224q95 = 4.2Bt = 2.26 TIp = 0.93 MAne0 = 8.6 x 1019 m -3
high * caseq95 = 4.4Bt = 2.37 TIp = 0.93 MAne0 = 10.3 x 1019 m -3
low * caseq95 = 4.4Bt = 2.85 TIp = 1.12 MAne0 = 10.3 x 1019 m -3
27 ITPA-IOS meeting, October 2011 J. Stober
IOS-4.3 : AUG-Proposal for 2012
- repeat rho* pulse with 5% higher Bt and modified ECRH angles- increase density by 20%- increase Bt and Ip 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 ITPA-IOS meeting, October 2011 J. 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 ITPA-IOS meeting, October 2011 J. 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 2012End of campaign November 2012
6 weeks without operation in August / September
30 ITPA-IOS meeting, October 2011 J. 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.)