Gyrokinetic Stability of Electron-Positron-Ion Plasmas

TL;DR

This study investigates the stability of electron-positron-ion plasmas using gyrokinetic theory, revealing conditions for stability and the presence of shear Alfven waves in contaminated plasmas.

Contribution

It derives and solves a dispersion relation for contaminated plasmas, analyzing stability thresholds and wave behaviors in a novel context.

Findings

Contaminated plasma remains stable below a certain ion contamination threshold.

Shear Alfven waves can exist in contaminated plasmas where they are absent without ion contamination.

The study provides insights into the stability criteria of electron-positron-ion plasmas.

Abstract

The gyrokinetic stability of electron-positron plasmas contaminated by ion (proton) admixture is studied in slab geometry. The appropriate dispersion relation is derived and solved. The ion-temperature-gradient driven instability, the electron-temperature-gradient driven instability, the universal mode, and the shear Alfven wave are considered. The contaminated plasma remains stable if the contamination degree is below some threshold, and it is found that the shear Alfven wave can be present in a contaminated plasma in cases where it is absent without ion contamination.