On the competition between the mirror and electromagnetic ion cyclotron modes

TL;DR

This paper analyzes the conditions under which mirror and electromagnetic ion cyclotron modes can exist or dominate in anisotropic high-beta plasmas, highlighting parameter regions for each mode and their competitive dynamics.

Contribution

It provides a simple argument delineating the exclusive and coexistence domains of mirror and electromagnetic ion cyclotron modes in high-beta plasmas.

Findings

Identifies parameter regions where only one mode can exist

Shows coexistence of both modes in certain domains

Suggests mode dominance depends on growth rates and nonlinear effects

Abstract

We give a simple argument for the exclusive existence of mirror and electromaghetic ion cyclotron modes in anisotropic high-$\beta$ plasmas. It is shown that, in addition to a large domain of coexistence of both modes, two domains exist in parameter space $(A,\beta_\perp)$ where solely either mirror modes or electromagnetic ion cyclotron modes can be excited. In the overlap region the modes with the larger growth rate should win. However nonlinear effects may modify such a conclusion.