Influence of ion-ion collisions and kinetic effects on minidisruptions of confined plasmas

Abstract

Resistive m=1 modes associated with minidisruptions of current carrying plasmas are shown to be strongly influenced simultaneously by the effects of finite ion gyroradius, finite drift wave frequency, and ion‐ion collisions in the plasma regimes of interest. The modes acquire finite frequency of oscillation and, for low β, the reduction in their growth rates is due mainly to the drift wave frequency, the effect of ion‐ion collisions being slight (less than 10% effect); but, even for low β, ion‐ion collisions significantly alter the radial structure of the modes. As a result, the reconnecting mode, which tends to lose its radial localization above a threshold temperature, remains well‐localized when ion‐ion collisions are included.