A digital control system for external magnetohydrodynamic modes in tokamak plasmas

Hanson, J. M.; Klein, A. J.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. Sunn
April 2009
Review of Scientific Instruments;Apr2009, Vol. 80 Issue 4, p043503
Academic Journal
A feedback system for controlling external, long-wavelength magnetohydrodynamic activity is described. The system is comprised of a network of localized magnetic pickup and control coils driven by four independent, low-latency field-programable gate array controllers. The control algorithm incorporates digital spatial filtering to resolve low mode number activity, temporal filtering to correct for frequency-dependent amplitude and phase transfer effects in the control hardware, and a Kalman filter to distinguish the unstable plasma mode from noise.


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