虚阴极振荡器中束流质量影响的粒子模拟

采用二维半全电磁PIC程序对轴向提取反馈式虚阴极振荡器中束流质量影响进行了模拟研究。结果表明：上凸前沿可使虚阴极振荡器达到饱和振荡的时间缩短，束脉冲前沿对微波饱和功率基本无影响；束流脉宽应大于16ns；当能散度为5%时，束波转换效率从单能束时的3.8%降至1.5%；束流质量（除能散度外）对微波频率基本上没有影响。

Particle simulation of beam quality effects on the operation of a vircator

This paper presents the simulation results of beam quality effects on the operation of a vircator with a 2.5 dimension particle in cell(PIC) code. The simulation results show that the front edge of the beam pulse has nearly no effect on the saturated microwave output, while a short steep front edge can accelerate the saturation of virtual cathode oscillation, and that the beam pulse width had better be over 16ns. According to the simulation, the microwave efficiency is decreased to 1.5% from 3.8% in the monoenergetic case when the energy spread of the beam electrons is 5%, and beam quality except the energy spread has almost no effect on microwave frequency.