Ion drift instability in a strongly coupled collisional complex plasma

TL;DR

This paper explores how ion drift influences wave instabilities in a strongly coupled, collisional complex plasma, highlighting the role of strong coupling in reducing sound velocity and promoting instability, with relevance to space-based experiments.

Contribution

It derives the general instability condition considering strong coupling and collisional effects, extending understanding of wave behavior in complex plasmas under ion drift.

Findings

Strong coupling reduces sound velocity in the plasma.

Ion drift facilitates the onset of instability.

Results are applicable to space-based plasma experiments.

Abstract

We investigate the low-frequency wave mode associated with heavy particles and its instability in a collisional complex plasma with drifting ions. The effect of the ion drift on the sound velocity of this mode is discussed. The general condition of the instability is derived for subthermal ion drifts, taking into account strong coupling of the particle component. As a general tendency, strong coupling effects reduce the sound velocity and facilitate the occurrence of the ion drift instability. A wide parameter range is considered from the weakly collisional to strongly collisional regimes for the ion and particle components. The chosen plasma parameters are representative to the PK-4 experiment, currently operational on board the International Space Station.