Analytic dispersion relation for resistive wall modes in rotating plasmas by generalized matching theory

Shiraishi, Junya; Tokuda, Shinji*

Analytic dispersion relation is derived for resistive wall modes (RWMs) in rotating plasmas, which gives the growth rate and the real frequency. The given parameters are wall information (radius, thickness, and volume resistivity) and equilibrium quantities at a plasma surface and near the singular point of the generalized Newcomb equation, which is an inertia-less linearized ideal magnetohydrodynamic equations with equilibrium rotation. Derivation of the dispersion relation is based on the generalized matching theory proposed by present authors, which exploits the inner "region" with finite width. It is found that the RWM stability is strongly affected by the rotation shear at the singular point of the generalized Newcomb equation, not at the rational surface.