Non-modal kinetic theory of the hydrodynamic drift instabilities of plasma shear flows

TL;DR

This paper extends the non-modal kinetic theory to study the long-term evolution of hydrodynamic drift instabilities in plasma shear flows, revealing a transition through a kinetic stage with decreasing instability growth rates over time.

Contribution

It introduces an extended kinetic framework to analyze the evolution of hydrodynamic instabilities in plasma shear flows, highlighting the non-modal effects caused by flow shear.

Findings

Hydrodynamic instabilities evolve through a kinetic stage.

Flow shear causes time-dependent reduction in instability frequencies.

Finite Larmor radius effects influence the non-modal evolution.

Abstract

The non-modal kinetic theory of the kinetic drift instability of plasma shear flows [Phys.Plasmas, 18, 062103 (2011)] is extended to the investigation of the long-time evolution of the hydrodynamic ion temperature gradient and resistive drift instabilities in plasma shear flow. We find, that these hydrodynamic instabilities passed in their temporal evolution in shear flow through the kinetic stage of the evolution. In linear theory, this evolution involves the time dependent, due to flow shear, effects of the finite Larmor radius, which resulted in the non-modal effect of the decrease with time the frequencies and the growth rates of the instabilities.