The first experimental demonstration of feedback suppression of rotating external kink modes near the ideal wall limit in a tokamak using Kalman filtering to discriminate the n = 1 kink mode from background noise is reported. In order to achieve the highest plasma pressure limits in tokamak fusion experiments, feedback stabilization of long-wavelength, external instabilities will be required, and feedback algorithms will need to distinguish the unstable mode from noise due to other magnetohydrodynamic activity. When noise is present in measurements of a system, a Kalman filter can be used to compare the measurements with an internal model, producing a realtime, optimal estimate for the system's state. For the work described here, the Kalman filter contains an internal model that captures the dynamics of a rotating, growing instability and produces an estimate for the instability's amplitude and spatial phase. On the High Beta Tokamak-Extended Pulse (HBT-EP) experiment, the Kalman filter algorithm is implemented using a set of digital, field-programmable gate array controllers with 10 microsecond latencies. The feedback system with the Kalman filter is able to suppress the external
A Kalman Filter for Active Feedback on Rotating External Kink Instabilities in a Tokamak Plasma
2009-05-01
oai:zenodo.org:3779180
Theses
Electronic Resource
English
tokamak , plasma , kink mode , kalman filter , feedback , control , instability , fusion energy , resistive wall mode
DDC: | 629 |
Further Experimental Evidences of the Development of Kink Instabilities in MPD Thrusters
British Library Conference Proceedings | 2005
|Wiley | 2000
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