调制电子束弛豫长度对哨声波辐射的影响

在发射调制电子束的主动空间试验中,电子束与背景等离子体的线性和非线性相互作用将产生哨声波辐射.影响辐射特性的因素很多,调制电子束的弛豫长度是其中一个重要因素.本文研究了呈指数衰减的调制电子束弛豫长度对电子束产生的哨声波辐射特性的影响.结果表明,当电子束弛豫长度与背景等离子体非均匀特征尺度相当时,有利于提高调制电子束产生的波辐射强度.

Effect of the Relaxation Characteristic Length of Modulated Electron Beam on Whistler Wave Radiation

During the active space experiments of radiating the modulated electron beam,the lin- ear and nonlinear interaction between the electron beam and background plasma may excite whistler wave.Characteristics of the excitation are determined by many factors,including velocity,relaxation characters of electron beam,the frequency of excited waves,and the density of background plasma. The relaxation characteristic length of the modulated electron beam is one of the important factors. In this paper,the influence caused by the exponential attenuation relaxation characteristic length of the modulated electron beam upon the characteristics of the wave excited by the electron beam were studied.Through solving the wave equation when the electron beam is injected into the ho- mogeneous anisotropy space plasma,the solution of the dispersion equation and the Poynting vector representation of the excited wave are obtained.It was shown that the wave radiation intensity excited by the modulated electron beam is enhanced efficiently when the relaxation characteristic length of the electron beam is comparable with the characteristic size of inhomogeneous background plasma.