Design and Implementation of Magneto Hydrodynamics Control System on HT-7 Tokamak

The instability of Magneto Hydrodynamics (MHD) in tokamak plasma is a main factor in deciding high performance operation of the tokamak device. Experimental and theoretical results have shown that plasma rotation can contribute to the stability of MHD. This paper presents a HT-7 MHD active control system using biased voltage electrode based on the MHD signal. Biased voltage produces drift and thus changes rotation of border plasma, while the biased voltage itself can be controlled and changed by intelligent control algorithm, and they can work together to realize MHD active control. This paper details the general architecture and implementation of the control system, which has been successfully adopted in HT-7 experiment in the spring of 2011 and generated useful information.