两互穿电子注-等离子体互作用的相对性理论

由两个等密度、反向电子注与重背景离子互作用所产生的电子注-等离子体互作用已经在理论上和实验上进行了研究。与文献1]和2]不同,本文提出一个较少限制的模型来讨论此种互作用机理的特性.该模型简略地示于图1。应用扰动理论,将已有的非相对论性模型推广应用于相对论性电子注和相对论效应对电子注-等离子体互作用的影响。此外已有的模型是被限制于等速、反向电子注在重背景离子等离子体中的互作用。本文根据相对论效应把该模型推广应用于非等速、平行或不平行的两个电子注。这个广义的理论不仅明显地显示了相对论效应.而且便于与熟悉的器件和过程,诸如行波管、邦内曼(Buncman)不稳定性以及皮尔斯(Picrcc}不稳定性相比较。导出了相对论性色散方程,并从这一相对论性互作用出发提出了一种新型自由电子激光。

RELATIVISTIC THEORY OF THE TWO INTERPENETRATING BEAM-PLASMA INTERACTION

The beam-plasma interaction resulting from two equal density,oppsitely directed elec-tron beams interacting with heavy background ions has been studied both theoretically and experimentallyin previous work,The nature of the interaction mechanism considered in this paper is illustratedschematically in Figure 1,a less restricted version of the model considered in references 1 and 2.We useperturbation theory to extend the previous non-relativistic model to include relativistic electron beams andthe influence of relativistic effects on the beam-plasma interaction.In addition,the previous model was re-stricted to oppositely-directed electron beams with equal speeds interacting in a heavy-ion plasma.We gen-eralize this model to include,along with relativistc effects,two beams of unequal velocity which are ei-ther parallel or anti-parallel.This generalized theory not only exhibits relativistic effects explicitly,butalso facilitates comparison with familiar devices and processes such as the traveling wave tube,theBuneman instability,and the Pierce instability.A general relativistic dispersion equation has been ob-tained,and a new class of FEL based on this relativistic interaction is proposed.