离子通道中相对论电子注的切连科夫辐射

对入射等离子体的相对论电子注(REB)在离子通道中可能产生切连科夫(Cherenkov)辐射的问题进行了论证与研究.利用线性理论分析了离子背景下的注-波互作用关系，导出了系统的色散方程与同步辐射条件.结果表明，系统的电磁不稳定性是由离子通道中TM模与电子注模通过电子注耦合所致，其微观机理是离子对电子注的聚焦.对处于运动等离子体状态下的离子-注系统进行了严格地理论分析，获得了通道内辐射波的频偏与波增长率公式，并通过数值模拟计算讨论了系统有关参数对它们的影响.关键词：离子通道等离子体切连科夫辐射

Cherenkov radiation of relativistic electron beam in the ion-channel

The problem that Cherenkov radiation may exist in the ion-channel when a relativistic electron beam (REB) is injected into plasma has been demonstrated and studied. The effect of the beam-wave interaction in ion background is analyzed by use of the linear perturbation theory. The dispersion equation and the simultaneous radiation condition of the system are derived. It is clearly shown that the electromagnetic instability of the system results from the coupling of the TM mode in ion-channel to the beam mode via the electron beam. Ion beam focusing is the microscopic mechanism. The ion-beam system in the moving plasma state is analyzed rigorously in theory. Then, the frequency shift of the radiation wave and the wave growth rate in ion-channel are presented. Finally, the effects of the parameters of the system on them are discussed by numerical calculation.