径向三腔渡越时间振荡器数值模拟

 基于渡越辐射机理结合径向结构的低阻抗特性，提出了一种新型的低阻抗高功率微波器件——径向三腔渡越时间振荡器，它由3个等间距的边耦合同轴腔组成，径向运动电子束与谐振腔中的角向均匀模式场相互作用。采用PIC粒子模拟程序进行了模拟研究。在电子束能量450 keV、束流60 kA且无外加引导磁场的条件下，当结构参数网长为4.8 cm,腔间距为1.4 cm,电子发射面为0.8 cm,内径为8 cm时，获得了平均功率7.4 GW，频率4.1 GHz的微波输出，效率达27.4%，阻抗7.5 Ω。通过粒子模拟给出了束波互作用效率随电子束电压、电流以及谐振腔间距的变化曲线，电子束电压对输出微波频率的影响曲线以及不同谐振频率与最佳谐振腔间距的对应曲线，这些曲线表明该器件具有渡越时间效应的基本特征，属于渡越辐射器件，且具有对电子束质量要求不高的特点。

Numerical simulation of radial three-cavity transit time oscillator

A new low-impedance of HPM source called radial three-cavity transit time oscillator is proposed based on the transition radiation and the low-impedance character of the radial structure. The oscillator is consisted of three side-coupling coaxial cavities which have the same cavity height. Circle symmetrical models are designed to effect with the electrons which moving in the radial direction. Through the PIC simulation, A C-band oscillator is designed, and the average operation power of 7.4 GW at 4.1 GHz is obtained, when excited by a 450 keV, 60 kA radial electron beam, with an impedance of 7.5 Ω. The vital character lines are obtained by simulation. Analysis result reveals that the oscillator has the basic characters of the transit time effect, and is of a transition radiation oscillat