Renormalized non-modal theory of the kinetic drift instability of plasma shear flows

TL;DR

This paper develops a renormalized non-modal kinetic theory for plasma drift instability in shear flows, highlighting the role of finite ion Larmor radius and turbulent scattering in suppressing turbulence.

Contribution

It introduces a nonlinear, renormalized non-modal approach to plasma drift instability, emphasizing the finite ion Larmor radius and turbulent scattering effects.

Findings

Finite ion Larmor radius suppresses drift turbulence.

Turbulent scattering of ion gyrophase rapidly reduces turbulence.

Non-modal decrease of instability growth rate over time.

Abstract

The linear and renormalized nonlinear kinetic theory of drift instability of plasma shear flow across the magnetic field, which has the Kelvin's method of shearing modes or so-called non-modal approach as its foundation, is developed. The developed theory proves that the time-dependent effect of the finite ion Larmor radius is the key effect, which is responsible for the suppression of drift turbulence in an inhomogeneous electric field. This effect leads to the non-modal decrease of the frequency and growth rate of the unstable drift perturbations with time. We find that turbulent scattering of the ion gyrophase is the dominant effect, which determines extremely rapid suppression of drift turbulence in shear flow.