高功率微波器件中脉冲缩短现象的粒子模拟

Simulation of pulse shortening phenomena in high power microwave tube using PIC method

脉冲缩短是高功率微波器件的一个普遍现象 ,它阻碍了输出微波能量的进一步提高 ,是高功率微波研究领域中急待解决的问题 .以相对论返波管作为研究对象 ,运用粒子模拟的方法 ,研究了器件表面的爆炸发射、电子束电压和电流的脉动对输出微波性能的影响 ,从中得到了一些有益的结论 ,指出由强电场引起的慢波系统表面的爆炸发射是产生脉冲缩短的重要因素 ,电子束电流和束电压的脉动也会引起脉冲缩短 。

Pulse shortening is an universal phenomenon in high-power microwave tubes, which hinders the improvement of microwave output energy. So far, it is also an unresolved problem in the field of high-power microwave devices. In this paper, the relativistic backward wave tube (RBWO) is treated as an example to study the pulse shortening phenomena. The influences of explosive emission in the inner surface of RBWO and fluctuation of the relativistic electron beam on the pulse width and output power are investigated by means of the particle-in-cell(PIC) method. Through the simulation results, some useful conclusions have been drawn. The explosive emission in the surface of the slow wave structure due to intense electric field is one of the most important factors causing pulse shortening in high-power microwave tube. The fluctuation of the electron beam can also lead to pulse shortening. Some methods to overcome pulse shortening are given in this paper.