1. George Sips ITPA, active control, 14 July 20031 Real-time Control ( and development of control systems ) at ASDEX Upgrade George Sips Max-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, D-85748, Garching,Germany.

2. George Sips ITPA, active control, 14 July 20032 Covers many physics areas, and various different diagnostic input data in real time. Areas for plasma control (development) at ASDEX Upgrade Control of plasma performance: (density profile, regime identification). Control of MHD instabilities: (NTM´s, sawteeth, ELM´s, ELM type). Control of q-profile, with on-line q(r) identification. Other control schemes including plasma protection.

3. George Sips ITPA, active control, 14 July 20033 Actuators at ASDEX Upgrade

4. George Sips ITPA, active control, 14 July 20034 Off axis heating: Peaking of density profile, but MHD unstable (NTM’s). Use of central ICRH or ECRH: Can control the density peaking. Control of density profile AIM: Density profile control, also including the heating power as actuator

5. George Sips ITPA, active control, 14 July 20035 Control of High Z impurities in the core Improved H-mode: NBI: 5 MW (2.5 MW off axis), ECRH, no sawteeth. With ECRH: Density peaking reduced, no accumulation of Tungsten.

6. George Sips ITPA, active control, 14 July 20036 Regime identification If you would like to know if the discharge is in L-mode or H-mode. Important for other control schemes: Density feedback, plasma protection, divertor. Use of power threshold scaling law is not sufficient at all. H-mode or L-mode

7. George Sips ITPA, active control, 14 July 20037 Regime identification Construct training data set > 3000 observations (by hand). Identify: H-mode or L-mode. Improved H-mode or not. Store for each data point 0-D diagnostic data. Automated search using discriminant analysis on best variables to use and optimimum number of variables. H-mode or L-mode dataset.

8. George Sips ITPA, active control, 14 July 20038 Regime identification H-mode or L-mode. Variables used for identification P loss,q 95,  p,I p,V loop Similar good results for Improved H-mode or Not Probability x 100%

9. George Sips ITPA, active control, 14 July 20039 3/2 NTM stabilisation More ECRH power, new mirror system for launch angle control. NTM detection algorithm using real time T e (r) data

10. George Sips ITPA, active control, 14 July 200310 Sawteeth control with ECCD Counter ECCD, 0.7 MW #15847 H-mode with 5 MW NBI Sawteeth stabilisation (A. Mück): Counter ECCD, inside q=1 surface. Co ECCD, just outside q=1 surface. ECCD deposition tuned with B-field. ECR deposition in  pol. -0.4 -0.2 0.0 0.2 0.4 4 0 6 2  ST /(  ST_no_ECR ) New gyrotrons and mirror system for 2003/2004 Co -ECCD

11. George Sips ITPA, active control, 14 July 200311 q 95 = 3.6,  sep. = 0.43,  N =3.5 q 95 = 3.7,  sep. = 0.44,  N =3.2 q 95 = 4.4,  sep. = 0.34,  N =2.2 q 95 = 3.3,  sep. = 0.17,  N =3.0 Control of ELM behaviour: plasma shape

12. George Sips ITPA, active control, 14 July 200312  x of the seperatrices at the outer midplane 0.5 0.4 0.3 0.2 0.1 <><> -0.06 -0.04 -0.02 0.00 x 0.2 - 0.4 n e /n GW 0.4 - 0.6 n e /n GW 0.6 - 0.8 n e /n GW > 0.8 n e /n GW q 95 > 3.5, pure Type II ELM´s possible. 0.85 < n e /n GW < 0.95. Close to double null shape. Type II Control of ELM type: Type II ELM´s access conditions

13. George Sips ITPA, active control, 14 July 200313 Controlled external ELM triggering Small pellets at 20 Hz are used to trigger ELM´s (P. Lang) Pellet trigged ELM is similar to natural ELM. IF  E can be maintained,  W ELM /W mhd can be reduced when f pellet > f natural-ELM A. Herrmann PSI 2002 ?

14. George Sips ITPA, active control, 14 July 200314 2 NBI sources (#6, #7) at NI-2 are off-axis, tangential injection at 93kV, Deuterium Higher current drive efficiency With other NB sources: Control of power/particle deposition  NBI system at ASDEX Upgrade : Motivation for current profile control at ASDEX Upgrade

15. George Sips ITPA, active control, 14 July 200315 NBI - power, source  MIMO system : MSE, Magnetic Probe Measurements Controller Adaptive PID Statistical Methods j (r), q (r) magnetic pitch angle data NBI FP ECCD Current profile control at ASDEX Upgrade

16. George Sips ITPA, active control, 14 July 200316 ASTRA Simulations of 4 different NBI sources

17. George Sips ITPA, active control, 14 July 200317 #17530 MSE signal : exp.VS. ASTRA 3 (MSE) 86 57 8 Astra Simulation vs Experiment at 400 kA Different NBI sources:

18. George Sips ITPA, active control, 14 July 200318 2 4 6 8 10  Neutral beam power modulated for optimum response on current diffusion time scale Time (s) Modulated NBI 5 10 ASDEX Upgrade ASTRA Simulations of modulated NBI sources These simulations are used to identify the system response function

19. George Sips ITPA, active control, 14 July 200319 Source6 - poloidal beta 98.1 % 55.6 % Source8 - j(0.225) best result worst result System identification and validation with step response

20. George Sips ITPA, active control, 14 July 200320 Otrher control schemes Control of several neutral particle flux densities via D gas injection. Choice of several different line densities control via D gas injection. (including edge density and possibility to switch during the pulse). Control of these line densites with pellet injection. Control of Tdiv (thermoelectric currents), or control of Pdiv via impurity gas injection. Control of isotope mix H/(H+D). Reduction of Halo currents. Pulse repair from Deep Detachment.

21. George Sips ITPA, active control, 14 July 200321 Control of H/(H+D) mixure and line average density

22. George Sips ITPA, active control, 14 July 200322 O : Without Killer pellet. : With mode-lock detector. X: With Killer pellet. Killer pellet activated with Neural net, trained to predict time to disruption. But network ages rapidly, to give < 80% reliability. Reduction of Halo current during disruptions

23. George Sips ITPA, active control, 14 July 200323 Deep detachment repair vs. Termination with killer pellet Repair, But experiment compromised ? Termination, Experiment finished Machine safe.

24. George Sips ITPA, active control, 14 July 200324 Design of new digital control system (ready 2003) Termination, Experiment finished Machine safe. Present system (own design):Transputer network,  ~ 2 - 5 ms New system (commercial):Shared memory netw.  ~ 1 ms

25. George Sips ITPA, active control, 14 July 200325 Conclusions Major new real time control schemes are being developed for ASDEX Upgrade: Density profile control, Regime identification, NTM and sawtooth stabilisation, ELM control and current profile control. Together with existing control scheme and real time diagnostic measurements form a consistent set of control tools. New real time control hardware is being installed and should be ready for commissioning in 2003