STABILITY OF IDEAL AND RESISTIVE MODES IN CYLINDRICAL PLASMAS WITH RESISTIVE WALLS AND PLASMA ROTATION

The stabilization of cylindrical plasmas by resistive walls combined w ith plasma rotation is analyzed. Perturbations with a single mode rati onal surface q = m/n in a finitely conducting plasma are treated by th e ''resistive kink'' dispersion relation of Coppi et al. [Sov. J. Plas ma Phys. 2, 533 (1976)]. The possibilities for stabilization of ideal and resistive instabilities are explored systematically in different r egions of parameter space. The study confirms that an ideal instabilit y can be stabilized by a close-fitting wall and a rotation velocity on the order of resistive growth rates [J. M. Finn, Phys. Plasmas 2, 378 2 (1995)]. However, the region in parameter space where such stabiliza tion occurs is very small and appears to be difficult to exploit in ex periments. The overall conclusion from the cylindrical plasma model is that resistive modes can readily be wall stabilized, whereas complete wall stabilization is hard to achieve for plasmas that are ideally un stable with the wall at infinity. (C) 1997 American Institute of Physi cs.