充中性气体相对论返波振荡器的粒子模拟研究

 用PIC粒子模拟方法研究了充中性气体相对论返波管的物理机制，成功模拟了电子束碰撞充入返波管中的中性气体电离产生等离子体的过程，在电子束传输的路径上形成离子通道，有效中和电子束径向空间电荷力，有利于电子束的传输及束波相互作用产生微波。增加中性气体密度，返波管的输出频率明显上移，其辐射的功率和效率比相同的真空器件也有明显的提高。

Particle simulation of RBWO filled with neutral gas

A particle-in cell (PIC) code is used to simulate the physical mechanism and interaction process of the relativistic backward wave oscillator (RBWO) filled with neutral gas. The simulation results reveal the production process of the plasma due to the collision of the relativistic electron beam (REB) with the neutral gas injected previously into the BWO tube. It is well known that the collision produced plasma may efficiently neutralize the space charge effect of the REB and enhance the production rate of the high power microwave. Our simulation results verify the above conclusion. It is shown that the increasing of the neutral gas density makes the output frequency obviously upper shift and the output power and energy conversion efficiency in the RBWO filled with neutral gas are higher than those in it without the gas.