矩形波纹过模周期慢波结构色散特性及其单模工作分析

 通过数值模拟，给出了一种求解矩形波纹过模周期慢波结构TM_0n模的色散关系的简便方法；研究了周期慢波系统平均半径、波纹周期、波纹幅度等结构参数对本征模式色散特性的影响；讨论了周期慢波系统中表面波与体积波的存在条件；分析了过模周期慢波系统仍能工作在单模状态下的原因。结果表明，过模周期慢波系统中，当结构参数满足一定条件，且与束电压、束半径匹配，使电子束与TM₀₁模同步点位于π模附近，此时TM₀₁模的总场是表面波，在两种选模机制作用下系统可实现TM₀₁单模工作。

Dispersive characteristic in the rectangular corrugation overmoded slow wave structure and analysis on its single mode operation

A convenient method is presented to obtain the dispersive characteristics of TM0n electromagnetic modes in the rectangular corrugation overmoded slow wave structure(SWS) by numerical simulation. The influence of average radius, period, amplitude of the SWS on the field distribution properties of the eigenmodes is investigated; the condition to maintain the surface and the volume waves is discussed; the reason that overmoded SWS can still operate in a single mode is analyzed. The results show that when the overmoded SWS structure parameters satisfy the condition and are matched with the annular beam voltage and radius, the total field of TM01 mode with longitudinal wavenumber of beam wave synchronous point locating near π mode is surface wave, and the system can operate in single TM01 mode under reaction of the two kinds of mode choosing mechanisms.