RESISTIVE WALL FEEDBACK STABILIZATION

A feedback system, which essentially makes a resistive wall appear ide ally conducting, is discussed. Such a system applied to a resistive wa ll surrounding a plasma will stabilize certain modes which would be un stable in the absence of the feedback system. The system discussed is similar to the ''intelligent shell'' by Bishop [Plasma Phys. Controlle d Fusion 31, 1179 (1989)]; it utilizes a number of autonomous subsyste ms, each covering only a fraction of the resistive wall. A model examp le discussed suggests that only relatively few autonomous subsystems a re needed and that the requirements of the electronics appear modest. (C) 1997 American Institute of Physics.