Drift wave stabilized by an additional streaming ion or plasma population

TL;DR

This paper demonstrates that adding a streaming ion or plasma population can effectively suppress the universal kinetic drift wave instability in electron-ion plasmas through flow-induced damping effects.

Contribution

It introduces a novel method of stabilizing drift waves by incorporating a flowing ion population, highlighting the critical role of flow speed and exponential damping response.

Findings

Flowing ions significantly damp the drift wave instability.

Damping effectiveness depends on flow speed relative to phase speed.

The stabilization persists for flow speeds less than the wave phase speed.

Abstract

It is shown that the universally unstable kinetic drift wave in an electron-ion plasma can very effectively be suppressed by adding an extra flowing ion (or plasma) population. The effect of the flow of the added ions is essential, their response is of the type (vph-vf0) exp[-(vph-vf0)^2], where vf0 is the flow speed and vph phase speed parallel to the magnetic field vector. The damping is strong and it is mainly due to this ion exponential term, and this remains so for vf0 < vph.