Drift-Alfven instabilities of a finite beta plasma sheared flow along a magnetic field with inhomogeneous ion temperature

TL;DR

This paper investigates drift-Alfven instabilities in a finite beta plasma with sheared flow and inhomogeneous ion temperature, revealing new instability mechanisms involving electromagnetic ion responses and ion temperature gradients.

Contribution

It introduces the electromagnetic ion kinetic response into the analysis, uncovering a new drift-Alfven instability driven by ion temperature gradients and flow shear.

Findings

Electromagnetic ion response significantly affects instability development.

New drift-Alfven instability driven by ion temperature gradient and flow shear.

Unstable waves have phase velocities comparable to ion thermal velocity.

Abstract

The drift-Alfven instabilities in the magnetic field aligned (parallel) sheared flow of a finite beta plasma with comparable inhomogeneous ion temperature and homogeneous electron temperature are examined. The development of instabilities are quantitatively discussed on the basis of numerical solution of a set of equations for the electrostatic and electromagnetic potentials. It is found that the accounting for the electromagnetic ion kinetic response, which has been ignored usually in existing discussions of the drift-Alfven instabilities of a steady plasma, reveals new drift-Alfven instability driven by the coupled action of the ion temperature gradient, the flow velocity shear, and the ion Landau damping. The excited unstable waves have the phase velocities along the magnetic field comparable with the ion thermal velocity, and the growth rate comparable with the frequency.