Oscillation spectrum of electron plasma, containing additive of background gas ions (azimuth number m=2)

Abstract

The spectrum of nonneutral plasma oscillations with azimuth number m = 2 is computed. Plasma, completely filling a wave guide, is composed of "cold" magnetized electrons and a small density fraction of ions, produced by ionization of background gas atoms by electron impact. The distribution function of ions is anisotropic one. The spectrum obtained consists of the families of "modified" ion cyclotron (MIC) modes and also of the families of electron upper hybrid (UH) and low hybrid (LH) modes (Trivelpiece–Gould modes) Doppler shifted by the electron rotation. Due to the Doppler shift the frequencies of electron modes fall into a region of ion frequencies and instabilities arise. The growth rates of UH modes are much faster than the growth rates of LH and MIC modes.