Ion heating and flow driven by an Instability found in Plasma Couette Flow

TL;DR

This paper reports the first observation of an instability in weakly magnetized plasma Couette flow, which leads to ion heating and is driven by Hall currents interacting with pressure profiles, supported by theoretical analysis.

Contribution

It introduces the first experimental observation of a Hall regime instability in plasma Couette flow and provides a linear theory explaining its growth and stabilization mechanisms.

Findings

Ion heating factor of 3 observed

Instability driven by Hall currents and pressure profiles

Theoretical predictions match experimental stabilization at high beta

Abstract

We present the first observation of instability in weakly magnetized, pressure dominated plasma Couette flow firmly in the Hall regime. Strong Hall currents couple to a low frequency electromagnetic mode that is driven by high-$\beta$ ($>1$) pressure profiles. Spectroscopic measurements show heating (factor of 3) of the cold, unmagnetized ions via a resonant Landau damping process. A linear theory of this instability is derived that predicts positive growth rates at finite $\beta$ and shows the stabilizing effect of very large $\beta$, in line with observations.