J. Stober, EC17, Deurne, May 2012 1
ECRH on ASDEX Upgrade
System Status, Feed-Back Control, Plasma Physics Results
Max-Planck-Institutfür Plasmaphysik
J. Stober, A. Bock, M. Reich, F. Sommer, W. Treutterer, D. Wagner, L. Gianone,A. Herrmann, F. Leuterer, F. Monaco, M. Marascheck, A. Mlynek, S. Müller, M. Münich,
E. Poli, M. Schubert, H. Schütz, H. Zohm and the ASDEX Upgrade TeamMax-Planck-Institut für Plasmaphysik, EURATOM Association, Garching, Germany
A. Meier, Th. Scherer, D. Strauß, A. Vaccaro, J. Flamm, M. Thumm Karlsruhe Institue of Technology, EURATOM Association, Karlsruhe, Germany
H. Höhnle, W. Kasparek, U. StrothInstitut für Plasmaforschung, Universität Stuttgart, Stuttgart, Germany
A. Litvak, G.G. Denisov, A.V. ChirkovInstitute of Applied Physics, RAS, Nizhny Novgorod, Russia
E.M. Tai, L.G. Popov, V.O. Nichiporenko, V.E. Myasnikov, E.A. Soluyanova, S.A. MalyginGYCOM Ltd, Nizhny Novgorod, Russia
J. Stober, EC17, Deurne, May 2012 2
Status: 4 MW in plasma (almost) reached
plasma currentplasma density
ECRH Power140 GHz
ECE diode
Sniffer probes
Power in plasma
New system:2.4 MW @ 140 GHz (0.82 + 0.76 + 0.85)or2.1 MW @ 105 GHz (0.76 + 0.56 + 0.75)
Old system: 1.5 MW for 2 s @ 140 GHz
J. Stober, EC17, Deurne, May 2012 3
Status of the new System
3 x 2-frequency gyrotrons (10 s)
Output power 2.7 MW @ 140 GHz (0.91 + 0.82 + 0.95)2.3 MW @ 105 GHz (0.84 + 0.62 + 0.84)
Last gyrotron expected July 2012 (initially 2-f)
X2, X3 with all beamlines and frequenciesO2 reflectors only for beamlines 5 and 6 @ 140 GHzO1 only @105GHz for Bt > 3T
J. Stober, EC17, Deurne, May 2012 4
Multi frequency project – window issues
Gyrotron window
- grooved-disk concept too fragile (A. Vaccaro, KIT)
- final concept: separately mountable ring resonator
Torus window- double disk window (FZK/KIT)
successful low power tests in 2007but failure at high power 2011 (600 kW, 4s)
- ring resonator difficult on AUG due to space limitations
If the resonator-window works, we consider the project a success.Further development of DD-window is considered a new project.
J. Stober, EC17, Deurne, May 2012 5
Ring Resonator Window (G. Denisov, IAP)
Start w/o resonator mid 2012
Commission resonator early 2013
MOU
J. Stober, EC17, Deurne, May 2012 6
System Status:Topics addressed by other contributions
FADIS and in-line ECEtalks by W. Kasparek, W. Bongers, N. Doelman
ECRH Stray-radiationposter by M. Schubert
J. Stober, EC17, Deurne, May 2012 7
Feed-Back Control
ECRH/CD as actuator of discharge control system (DCS) :
Power control under DCS: on/off tested; analogue prepared
Mirror control under DCS: new system only, one axis only
J. Stober, EC17, Deurne, May 2012 8
New scheme: allows simultaneous central heating
old scheme:central ECRH impossible
new scheme:needs well focussed beam
NTM stabilisation - Concept
J. Stober, EC17, Deurne, May 2012 9
NTM control – FB control scheme
Real-Time Data Network
→ Torbeam
Gyro-trons
ECE
→
ECH,EQU
NTM,ECE NTM
Psetset
set
Te,ch
dB/dt
ECH
3/2 & 2/1corre-lation
z+()
z-
()
r
fch
MAX
B, m
rt-EQU
ne
DCNMirror drives
modelocation
ECE(ch,z)
pol(r, z)
q_res,EQU
ECH P
ne-profile
ne()
Data Acquisition Hardware
MSX
MHDcontroller
MIR
n=1 n=2analogue
from MIRd/d
J. Stober, EC17, Deurne, May 2012 10
NTM control – Launcher alignment
CorrelationECE&linear comb. ofMirnov datacorresponding to(n=2) or (2,1)
Amplitude
Phase
mode location
RT-TORBEAM
(M. Reich et al., FST 2012)
J. Stober, EC17, Deurne, May 2012 11
NTM control – First feed-back attempts (28.4.2012)
After ~ 100 ms minimum in n=2 amplitude
lose robust localization / tracking
rho (NTM) = rho (n=2) - 0.025
Wmhd
beta_pol
beta_N
ICRH
Amplituden=1n=2
J. Stober, EC17, Deurne, May 2012 12
Holographic Mirror with fast thermocouples to control beam position
1st pass
2nd passtop view
O2 heating – Concept (PhD-Thesis H. Höhnle)
J. Stober, EC17, Deurne, May 2012 13
O2 heating – FB control scheme
(FF) (FB)
on – off (FF)interlock Tmax
J. Stober, EC17, Deurne, May 2012 14
Example : O2 heating with FB control
TC for beam controland interlock
PO2 [MW]
ne [1020 m-3]
H-1
H-5
controllerthreshold
(TTC,b-TTC,t) Kp [a.u.]
Beam position after feedbackcontrol
Beam position before feedback control
TC forinterlock
poloidal launcher angle [mm]
mirror
FB – control correctslaunching angle within 50 ms
J. Stober, EC17, Deurne, May 2012 15
Plasma physics results
ECRH/ECCD is used in the majority of the AUG physics studies
review out of scope
Recent studies using high EC power
- L/H threshold at low density
P. Sauter et al., NF 2012
- Rotation and toroidal momentum transport
R. McDermott et al., PPCF 2011
- Advanced Tokamak scenarios
MSE analysis in progress
- Influence of heating mix on transport in H-mode (core/edge)
J. Stober, EC17, Deurne, May 2012 16
Comparison NBI - ECRH [- ICRH] (F. Sommer et al.)
H-mode, q95 = 4.0, fGW = 0.75
Wmhd ~ 350 kJ, Prad ~ 1.5 MW, fELM ~ 50 Hz, H98 ~ 0.8, βN ~ 0.95, eff ~ 2
Ptotal 3 MW
4 phases:- 0 NBI
2.7 ECRH- 0.8 NBI
2.0 ECRH- 1.6 NBI
1.2 ECRH- 2.4 NBI
0.6 ECRH
J. Stober, EC17, Deurne, May 2012 17
Influence of PECRH on kinetic profiles (ne, Te,i, vtor)
With increase of ECRH frac.
• ne
peaking increases
• Te
less than 600 kW ECRH 20% Te increase
• Ti
1/3 of ECRH power 15% decrease,effect saturates
• vrot_tor
decreases (reduced torque input)
only minor variations at the pedestal
NBI fraction rises
J. Stober, EC17, Deurne, May 2012 18
Ion heat transport increases with ECRH fraction
Increase of ion heat diffusivities as PECRH increases
- consistent with theoretical expectations for variation of Te/Ti
ECRH NBI2.7 MW2.0 MW 0.8 MW1.2 MW 1.6 MW0.6 MW 2.4 MW
3.0 MW
#27242
F. Sommer et al., accepted by NF
J. Stober, EC17, Deurne, May 2012 19
Outlook
ECRH-System
- New ECRH system will be completed in 2012 (2f)
- Long pulse 4f-gyrotron operation foreseen for early 2013
- Replacement of old system by 4 x 1MW/10s/2f in progress
Feed-Back Control
- Focus of FB control development in 2012 campaign on NTMs
- Flexible RT-diagnostic layer easily adapted to new tasks
Plasma Physics Studies
- Characterize dominantly EC heated H-modes at lower nu*
- many others
J. Stober, EC17, Deurne, May 2012 20
J. Stober, EC17, Deurne, May 2012 21
Future of multi-frequency project
a) close project- realisation of long-pulse mf-gyrotron would be big success.- In principle also suitable for torus, but not in AUG set-up.
b) continue- find reason for failure of DD-window (full wave simulation)- modify DD-Window if necessary.- build torus-window test-stand in Garching- start with high power short pulse, measure stray radiation and cooling requirements compare to calculation- long pulse tests in test-stand- mount DD-window to torus
under discussion with KIT
J. Stober, EC17, Deurne, May 2012 22
Zoom on edge profiles (ne, Te, vtor)
With increase of ECRH frac.
• ne
no change
• Te
10 % reduction
• Ti
no change
• vrot_tor_edge
decrease (reduced torque input)
• vrot_pol_edge
no change
J. Stober, EC17, Deurne, May 2012 23
Grooved disk too fragile (A. Vaccaro, KIT)
Details: A. Vaccaro et al. , Proceedings IRMMW 2011
J. Stober, EC17, Deurne, May 2012 24
Failure of double disk window
Conditioning with increasing pulse length
3 s pulse with 620 kW successfull (#26271)
4.1 s pulse with 580 kW lead to failure (#26277)
- Gyrotron switched of by inter-disk vac. control (5x10 - 4 mbar)- no arcs detected- water found in inter-disk volume
- Effect of non-perfect beam ?- Operation with 2 inclination?
Increase of stray radiation measured +7 db (post mortem).
Steam-bubble in cooling channel?
J. Stober, EC17, Deurne, May 2012 25
Broken double disc window
Air-side disk, light from behind
J. Stober, EC17, Deurne, May 2012 26
- minimum bandwidth 200 MHz must include frequency drift- accuracy of positioning < 5 m - needs evacuation 80 mm
KIT double disc window
J. Stober, EC17, Deurne, May 2012 27
torus-window test facility
3 Mitre bends+ wave guides
movable mirrorin load-MOU
wave guideconnectorto load-MOU
windowtestfacility
J. Stober, EC17, Deurne, May 2012 28
torus-window test facility
J. Stober, EC17, Deurne, May 2012 29
Comparison NBI - ECRH [- ICRH] (F. Sommer et al.)
• 27247 : LSN, H-mode, Ip ~ 1 Ma, Bt ~ 2.5 T q95 = 4.0, ne ~ 9 x 1019 m-3
• Constant global Plasmaparameter:
• Wmhd ~ 350 kJ, Prad ~ 1.5 MW, fELM ~ 50 Hz, H98 ~ 0.8, βN ~ 0.95, eff ~ 2
Ptotal 3 MW
4 phases:- 0 NBI
2.7 ECRH- 0.8 NBI
2.0 ECRH- 1.6 NBI
1.2 ECRH- 2.4 NBI
0.6 ECRH