Comparison of RWM Stabilization Strategies in DIII-D
S. Yang, E. Schuster, D.A. Humphreys, M.L. Walker, Y. In, J-S. Kim
Division of Plasma Physics (DPP) Annual Meeting of the American Physical Society (APS)
Dallas, Texas, November 17-21, 2008
Abstract
|
|
One of the major non-axisymmetric instabilities under study in the
DIII-D tokamak is the resistive wall mode (RWM), a form of plasma kink
instability whose growth rate is moderated by the influence of a
resistive wall. The FAR-TECH/General Atomics RWM dynamic model
represents the plasma surface as a toroidal current sheet and
represents the wall using an eigenmode approach. This dynamic model is
used for the design of model-based controllers that have the potential
of outperforming present proportional-derivative (PD) controllers. We
report on validation of this dynamic model, a required step before
implementation of any model-based controller in the DIII-D plasma
control system. In addition, simulation results are presented comparing
the performance of advanced controllers synthesized using the validated
dynamic model and present non-model-based PD controllers.