High-frequency electron drift instability in the cross-field configuration of Hall thrusters

TLDR

The instability has very large wave numbers with wavelengths close to the electron gyroradius. The study systematically investigates a high‑frequency electron drift instability. The authors derive a 3‑D dispersion relation for a crossed E‑B configuration in a Hall thruster and study the instability evolution using particle‑in‑cell simulations of distorted electron distributions. The instability manifests as packets of oblique modes perpendicular to the magnetic field.

Abstract

A systematic study of a high-frequency electron drift instability is presented. It has very large wave numbers corresponding to wavelengths close to the electron gyroradius. The three-dimensional dispersion relation is derived for a model of a crossed electric and magnetic field configuration existing in the Hall thruster. It is shown that the instability develops in packets of oblique unstable modes perpendicular to the magnetic field. The evolution of the instability is also studied for distorted electron distribution functions obtained in particle-in-cell simulations.