Fluctuation Mitigation and Azimuthal Velocity Profile Regulation by Extremum Seeking in HELCAT
Z. Ilhan, J. Barry, H. Wang, E. Schuster, M. Gilmore, A. Ware
Symposium on Fusion Engineering
San Francisco, California, USA, June 10-14, 2013
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Abstract
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Turbulence, and turbulence-driven transport are ubiquitous in
magnetically confined plasmas, where there is an intimate relationship
between turbulence, transport, desta- bilizing mechanisms like gradients
and currents, and stabilizing mechanisms like shear. Active control
of fluctuations via manipulation of flow profiles is investigated in a
magnetized laboratory plasma device (HELCAT). Measurements of the
azimuthal velocity are assumed available at several radial points within
the plasma and ExB flow profiles are controlled via biased ring
electrodes. An optimal control algorithm is proposed in this work to
reproduce as closely as possible a prescribed desired radial azimuthal
velocity profile. The effectiveness of the controller is analyzed via
numerical simulations.
