同轴内导体盘荷慢波结构注波互作用机理研究

采用理论分析和粒子模拟方法研究同轴内盘荷慢波结构注波互作用的物理机理。采用场匹配理论得到色散方程，通过数值计算得到了准TEM模的色散曲线及不同电子注电压下注波互作用的增长率；采用粒子模拟技术研究了注波互作用的物理过程。结果表明，随着电子注电压的不断增加，器件的工作状态由返波振荡转换到行波振荡；通过对辐射谱特性进行分析表明粒子模拟结果与理论计算结果基本一致。

Study on beam-wave interaction mechanism in the disk-loaded-inner-conductor coaxial slow wave structure

The physical mechanisms of the beam-wave interaction for coaxial inner conductor Slow Wave Structure（SWS） are studied by theoretical analysis combined with Particle-In-Cell（PIC） simulation. The dispersion equation is derived by field matching method, the dispersion curves of quasi-Transverse Electromagnetic FieId（TEM） mode and the growth rate of the beam-wave interaction under different voltages of electron beams are studied by numerical calculation. Through PIC simulations, the physical mechanisms of the beam-wave interaction are analyzed. The simulation results show that the working status of the device switches from backward oscillations to forward oscillations with the increasing of the electron beam voltage. It is also found that the PIC simulations are basically in agreement with the theoretical calculations by analyzing the characteristics of the electromagnetic radiation.