Unstable modes of oscillations of a tangential discontinuity in partly ionized plasma with charge exchange: long waves

Abstract

An analytical study of linear unstable modes of oscillations of a tangential velocity discontinuity in partly ionized space plasma with charge exchange is carried out.The long-wave approximation is considered. In this approximation, the scale of perturbations is much larger than a certain characteristic size, which is determined by the charge-exchange cross-section and number density of neutral atoms. It is shown that along with the classical Kelvin – Helmholtz instability, there exists an unstable mode whose increment does not depend explicitly on the relative velocity of the two media separated by the discontinuity. The presence of this mode is entirely determined by the presence of the charge-exchange process.