中等相对论性电子环-束引起的束迴旋不稳定性

本文研究了在电子等离子体频率ω_e远大于电子迴旋频率Ω_e的等离子体内,由中等相对论性电子环-束激发的高频(ω≥ω_e)束迴旋不稳定性。结果表明,高能电子束迴旋模在N2cos2θ<1和N2cos2θ>1范围内都是不稳定的,在N2cos2θ=1时是稳定的,这里N为折射指数,θ为传播角。当束迴旋模频率近乎等于冷背景等离子体本征模频率之一(ω≈ω_e)时增长率最大。文中介绍和讨论了色散方程的数值计算结果。 

Beam-Cyclotron Instabilities by Moderately Relativistic Electron Ring-Beam

High frequency (ω>ω_e) beam-cyclotron instabilities excited by moderately Jelativistic electron ring-beam are studied in regions where the electron plasma fre-quency wc is much higher than the electron cyclotron frequency Q_e(i.e.ω_e2>>M_e2).It is found that the beam-cyclotron modes of energetic electrons are unstable in the cases of N2cos2θ<1 and N2cos2θ>and stable in the case of N2cos2θ=1,where N is the refractive index and d is the propagation angle.When the frequency of beam-cyclotron mode is nearly one of the eigenmodes of cold background plasma,i.e.to ≈ω_e,the growth rate is the largest.Numerical solutions of the dispersion equation are also presented and discussed in this paper.