Integrated Magnetic and Kinetic Control of Advanced Tokamak Scenarios Based on Data-Driven Models
D. Moreau, F. Liu, J.R. Ferron, D.A. Humphreys, E. Schuster, M.L. Walker, J.F. Artaud, J.E. Barton, M.D. Boyer, K.H. Burrell, S.M. Flanagan, J. Garcia, P. Gohil, R.J. Groebner, C. Holcomb, A.W. Hyatt, R.D. Johnson, R.J. La Haye, J. Lohr, T.C. Luce, R. Nouailletas, J.M. Park, B.G. Penaflor, W. Shi, F. Turco, W. Wehner, and ITPA-IOS group members and experts
IAEA Fusion Energy Conference
San Diego, California, USA, October 8-13, 2012
Abstract
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The first real-time profile control experiments integrating magnetic
and kinetic variables were performed on DIII-D in view of regulating
and extrapolating advanced tokamak scenarios to steady state devices
and burning plasma experiments. The integrated model-based approach
that was used is generic and is being developed under the framework of
the International Tokamak Physics Activity for Integrated Operation
Scenarios. Device-specific, control-oriented models were obtained from
experimental data and these data-driven models were used to synthesize
integrated magnetic and kinetic profile controllers. Closed-loop
experiments were performed for the regulation of (a) the poloidal flux
profile, Ψ(x), (b) the inverse of the safety factor profile, ι(x)=1/q(x),
and (c) either the Ψ(x) profile or the ι(x) profile together with the
normalized pressure parameter, βN. The neutral beam injection (NBI),
electron cyclotron current drive (ECCD) systems and ohmic coils provided
the heating and current drive (H&CD) sources. The first control actuator
was the plasma surface loop voltage or current (i. e. the ohmic coil),
and the available beamlines and gyrotrons were grouped to form five
additional H&CD actuators: co-current on-axis NBI, co-current off-axis
NBI, counter-current NBI, balanced NBI and total ECCD power from all
gyrotrons (with off-axis current deposition). The control method was
also applied on simulated ITER discharges using a simplified transport
code (METIS).