TORE SUPRA 2011 X LITAUDON on behalf of

TORE SUPRA : 2011 X LITAUDON on behalf of TORE SUPRA TEAM CEA-IRFM, Institute for magnetic fusion research (IRFM) CEA Cadarache F-13108 St Paul Lez Durance. France e-mail: xavier. litaudon@cea. fr ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 1

2011 Experimental Campaign Ø 21 April up to end July 2011 Ø Overall Coordination – Experiments & physics programme B. Saoutic & Y. Corre – Technical coordination M. Houry Ø Three Task forces – Qualification of new CW LHCD system ( ITER launcher and transmitter): A. Ekedahl – Development of long pulse scenario : R. Dumont – ITER operation preparation: S. Bremond ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 2

Scenario development: extended domain of steady-state operation 2011 Scenario Development: ØHigh energy with LHCD 5 MW LHCD 400 s ØHigh energy with ICRH 4 MW LHCD + 3 MW ICRH 200 s ØHigh power discharges 6 MW LHCD + 9 MW ICRH 30 s ITPA-IOS group, Kyoto, 18 -21 October 2011 + Physics thrusts on MHD, transport, rotation X. Litaudon on behalf of Tore Supra team 3

TORE SUPRA 2011 Ø LHCD: Recent large upgrade – 2009: Installation of PAM launcher – 2010 -11: 8 new klystrons on FAM Ø ICRH: – up to 9 MW during 30 s (3 antennae) – or 3 MW long pulse – New Faraday screen (one antenna) Ø ECRH: – 700 k. W during 5 s Ø IR monitoring: – for RF operation & to protect fully actively cooled tokamak Ø Upgrade diagnostics – Reflectometry ITPA-IOS group, Kyoto, 18 -21 October 2011 TED 2103 C Klystrons X. Litaudon on behalf of Tore Supra team 4

New CW klystrons validated on plasma operation Coupled power: 3. 8 MW (> 4. 0 MW at klystrons) with Full Active Multi-junction launcher (FAM), fed by a set of eight 700 k. W/3. 7 GHz CW klystrons. TH 2013 C: 700 k. W CW on matched load #48081 <ne> (1019 m-3) PLH = 3 MW L. Delpech et al. , 19 th RF Conf. , Newport (2011) G. Berger-by et al. , 19 th RF Conf. , Newport (2011) ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 5

Long pulse operation with both LHCD launchers Both LHCD launchers together 4. 5 MW/150 s obtained (650 MJ injected energy) Opens new operational space (ne, IP) for long pulse operation Total PLHCD PAM, FAM Slow increase in density due to nonoptimised feedback control A. Ekedahl et al. , 19 th RF Conf. , Newport (2011 ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 6

Control improvements for long pulse operation: transition to feedback controlled loop voltage Issue: jump in Lower Hybrid power during transition from Ip control to (VG 0, PLH) <-> (Ip, Vloop) control Development : Multi Input Multi Output feedback control 1 Ph Moreau TS#38488 Flux (Wb) 0. 5 0 8 6 4 2 0 1. 5 1 0. 5 0 -0. 5 3 2 1 0 Plh (MW) Vg 0 (k. V) Typical situation before Ip (MA) Control oriented model development, feedback control design and test on simplified model and on METIS code, experimental validation 0 5 10 15 20 25 30 New MIMO control now in routine operation ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 7

Measurements of Density Profile in the Scrape-off-Layer with Reflectometer Embedded in the LHCD Full Active Multijunction Antenna q Crucial to study LH coupling and SOL physics q Strong increase of density gradient in the SOL during LHCD C. Bottereau et al. 2011 ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 8

Ray-tracing modelling of full current drive discharge Full CD regime (PAM alone) for 50 s n// spectrum (ALOHA) Ø n// spectrum from ALOHA code (using measured values of power, phase and edge density) Hillairet et al Nucl. Fusion 50 125010 Ø Ray tracing code, C 3 PO, using 36 Y Peysson and J Decker. EPS 2011 & rays (6 n//-values x 6 waveguide rows) PPCF ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 9

Good agreement with modelling, in this example LH current profile for #45534 Line integrated HXR emission IPlasma exp: 510 k. A ILH LUKE: 508 k. A ILH Cronos/HXR: 443 k. A Experiment Modelling Dfast = 0. 1 m 2/s C 3 PO/LUKE reproduce well the HXR profile and the driven current. Synthetic diagnostic models well the line integrated HXR emission. Y Peysson and J Decker, Phys. Plasmas (2008) J Decker et al. , 19 th RF Conf. , Newport (2011) Although good agreement in this example, robustness in LHCD modelling is still required. Y Peysson et al. , 19 th RF Conf. , Newport (2011) ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 10

ITPA-IOS experiment: LHCD modelling vs HXR measurement TS#45155 PLH =2 MW At first order IHXR ~ nenfast. Zeff f(Z) ~h Zefff(Z)~Te Zefff (Z)~ne-2 IHXR, experimental ~ <ne> -2. 5, -3. 5 ILH~h ne-1~Tene-1~ne-2 ILH, computed ~ ne-3 ØExperimental HXR scaling (ne-2. 5, -3. 5) is consistent with RT/FP computation of ILH Goniche et al and Oosako et al RF 2011 conf. ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 11

ITPA-IOS experiment, LHCD experiments at High Density : Gas vs. Pellet Fuelling and role of edge fluctuation • HXR emission stronger with pellets when ne>4× 1019 m-3 • Faster decay of HXR correlated to strong increase of SOL density fluctuation Goniche et al RF & EPS 2011 conf. ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 12

High density long pulse operation with LHCD & ICRH: new GJ discharges in 2011 !! Tore Supra # 47979 19 ICRF reduced by RT protection: • B~1 GJ (~6. 3 MW/150 s) o~ 3. 8 T, nl = 4. 1 x 10 m overheating LHCD coupler 3, Iof = injected/extracted 0. 7 MA p energy bp ~0. 6, b. N ~ 0. 7 PLHCD = 2 -6 MW PICRH = fraction 1 -3 MW • Non-inductive ~80% with sustained e. ITB! R. Dumont et al ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 13

ICRF power stabilizes MHD activity in non-inductive LHCD discharges as expected [ M. Zabiego et al, PPCF 2001 ] MHD activity ~500 ms after ICRH swith-off Tore Supra # 47319 R. Dumont et al ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 14

q-profile & improved confinement sustained in the GJ discharges Ø electron ITB: Ø Global confinement – Low magnetic shear in core – High magnetic shear in confinement domain Tore Supra # 47979 R. Dumont et al ITPA-IOS group, Kyoto, 18 -21 October 2011 Ph. Lotte et al X. Litaudon on behalf of Tore Supra team 15

Large central temperature variations: coupling q & transport (through bootstrap current ? ) Tore Supra # 48161 C. Bourdelle 2011, Giruzzi et al PRL 2003, Imbeaux et al PRL 2005 ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 16

First Observation of Turbulence Dynamics in the Scrape-off-Layer (SOL) with Ultra-Fast Sweep Reflectometry q Strong intermittent behaviour into the SOL Spatial origin of “Blob-like” structures well identified radially q New plasma physics issues Blob-like structure observed in the SOL of plasmas heated by ICRH F. Clairet, 38 th EPS Strasbourg June 2011 17

2011: New Faraday Screen for ICRH Antenna q Designed to minimize RF sheath potential & mechanical constraint on FS Bars Simulated RF potentials q Leak tests validated: jan. 2011 q RF tests on new test bed facility: 03/11 q Experiments on Tore Supra: RF sheath physics, power coupling, impurity production, thermal cooling; with participation of ITER-IO & ICRH experts new concept L. Colas, K. Vulliez R&D aspects relevant for ITER ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 18

Measurement of the DC floating potential with RF fields (Tunnel probes) Probe q(a)=7. 5 Ref. plane IC ant. Probe 0. 5 Z(m) q /p 0. 5 0 IC ant. q(a)=7. 5 0 q(a)=3. 2 -0. 5 0 0. 5 f 1/p 1. 5 2 2 ITPA-IOS group, Kyoto, 18 -21 October 2011 2. 5 R(m) 3 J. Gunn, M. Kubic EPS 2011 X. Litaudon on behalf of Tore Supra team 19

Thermo-mechanical calculation and comparison to experiments Ø Thermo-mechanical modelling reproduces experiments Ø actively cooled Faraday screen: good thermal response Ø But the local heat flux is 10 times higher compared to standard FS – 375 -690 k. W/m 2 Ø consequences for ITER design M. Firdaouss ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 20

Other issues related to ITER operation preparation Ø Disruption runaway electrons suppression by high pressure fast gas injection Ø Event / Exception handling Ø High density/high radiation Operation Ø EC assisted plasma start-up : assistance to plasma start-up by 2 nd harmonic X-mode ECRH with 20° tangential injection (ITER at half magnetic field) Ø Effect of local gas puffing on IC/ LHCD power coupling Ø Heat flux pattern on leading edge of misaligned tile Ø Characterisation of the SOL near limiter plasma tangency point Ø Wall conditioning by low frequency glow discharges and by Ion Cyclotron ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 21

Runaway electron mitigation by high pressure fast gaz injection Ø Motivation : suppression of runaway electron in ITER by fast injection of dense gas jet in the current quench (alternative to massive material injection) ØFIRE setup (Fast Injection by Rupture disk Explosion) developped sucessfully (ITER contract) HV conductor Cartridge body Spring electric arc F. St Laurent ITPA-IOS group, Kyoto, 18 -21 October 2011 Rupture disk X. Litaudon on behalf of Tore Supra team 22

First results: neon gas flow observed by fast camera Propagation of the Neon gas injected by Fire from the top of the machine during plasma current quench Fast visible camera images filtered for Ne I line. Front moves with v ~500 m/s for Ne and 1200 for He (1/2 of gas velocity in vacuum) F. St Laurent ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 23

Modelling of Event / Exception handling 0. 6 4 Nl (x 10+19 m-2) 0. 4 Ip 0. 2 0 8 2 Vloop/5 0 2. 0 Power (MW) 6 ICRH 4 ROG (cm) 2. 2 LHCD#2 2 LHCD#1 0 2. 4 Temperature (°C) LH#2 600 LH#1 400 200 0 10 LH#1 unavailable 20 LH#2 Temp threshold Missing power redistribu- ROG is increased, ted on LH#2 to ensure Vloop 0 during transient Vloop=0 (Ip maintained) 30 Time (s) LH#2 unavailable Vloop=0 not recovered Vloop 0 to maintain Ip Soft Stop is triggered Local E/E report Orange Red Red Global E/E report Green Orange Red R. Nouailletas ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 24

ne/n. Gr=1. 4 maintained for several t. E in RF heated plasmas with 90% radiated power Ø Regime similar to ‘high recycling’ regime in axisymmetrix X-pt divertors Ø No degradation of global energy confinement ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 25

Tore Supra: prepare ITER long pulse operation Ø Plasma operation restarts in Sept. 2012 – Shutdown: modification of HV 400 k. V network for ITER Ø Full H&CD CW capability & 2012 upgrade – 6 -7 MW LHCD (CW) + 3 MW ICRH on more than ~200 s – Assess power limit of CW ITER-PAM – Antenna & machine protection upgrade – Diagnostics upgrade: fast core reflectometry – ECRH antenna upgrade (in collaboration with FOM): Mirror mouvement for real time control Ø Master long pulse operation: minimising risks for ITER – fully non-inductive plasmas at higher Ip and density – Disruption mitigation – real time control for machine protection & performance optimisation: IR control of hot spots, ripple fast losses. . . – Physics of evanescent Vloop plasma on time scale much longer than current diffusion: MHD, intrinsic rotation, . . . ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 26

WEST : minimising risks for ITER operation Use Tore Supra assets to prepare ITER exploitation ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 27

WEST : extending H mode towards steady state and exploring PWI with actively cooled W ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 28

Thanks for your attention ! ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 29

Stationary electron ITBs in LHCD & ICRH long pulse discharges 2011 discharges Typical Te profiles R. Dumont et al ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 30

Barrier characterization with ECCD Tore Supra # 47968 HXR signal (60 -80 ke. V) Balanced co/cnt-ECCD (PEC ~ 0. 8 MW) During ECCD Before ECCD G. Giruzzi et al ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 31

CRONOS interpretative transport analysis: clear e-ITB in the low magnetic shear region C. Bourdelle Normalised radius ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 32

48161, discharge with Te oscillations 47901, with e. ITB ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 33

After oscillations ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 34

ITER context Ø RF sheath modelling with RF fields from TOPICA – Non consistent calculation Ø Minimisation of RF sheath by minimising the E// (slow wave) Ø Design of New Faraday screen on Tore Supra based on the same modelling approach 6 poloidal by 4 toroidal staps , 40 -55 MHz, 20 MW ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 35

Self-consistent non-linear ICRH wave propagation and RF sheath rectification • RF sheath rectification treated as Slow Wave propagation self-consistently coupled with DC edge plasma biasing. Non-linear coupling is ensured via RF and DC sheath boundary conditions. • DC current generation: – the differential biasing of adjacent flux tubes connected electrically via DC transverse plasma conductivity – asymmetric RF solicitation at both ends of the field line Colas EPS 2010, Jacquot RF conf 2011 ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 36

Event / Exception handling architecture overview Plasma scenario Operation limits Desired references (pulse references) E/E handling Optimized requests B C E/E handling Plasma E/E handling Raw data Fault detection Group 2 A B Actuators C Diagnostic 1 Diagnostic 2 Plasma state Equipment layer A E/E handling Actuator status Group 1 Desired plasma state Checked outputs Reports Central control Local control layer Overall E/E handling Diagnostics Plasma ITPA-IOS group, Kyoto, 18 -21 October 2011 X. Litaudon on behalf of Tore Supra team 37

Implementation of an E/E handling system on a tokamak/plasma simulator ICRH models Solenoid + METIS Ref Basic plasma models Circuit equation (R, Li, M, constant) Op limits LCS ILHCD RCS VCS M Rplasma Ip Plasma status Ohmiccurrentsource Local E/E handling LHCD models ICRH Events Li Global E/E handling PFC temperature ITPA-IOS group, Kyoto, 18 -21 October 2011 Non inductiv current source 0 -D plasma models replaced by METIS code plasma evolution simulation Current diffusion solver Grad-shafranov equation solver Scaling law for plasma paramete (inductive/non inductive current, etc. ) ICRH strap voltage and reflected power X. Litaudon on behalf of Tore Supra team 38