3mm低电压回旋管设计与模拟

Design and Simulation of a 3 mm Low-Voltage Gyrotron

设计了一种3mm低电压二次谐波渐变结构复合腔回旋管,采用二次回旋谐波工作可以在获得高效率的同时,降低工作磁场到基波工作所要求磁场的1/2,使磁场系统简单紧凑。选择工作电压为25kV,可以降低回旋管对绝缘的要求和供电系统的体积及重量;采用渐变结构复合腔控制模式竞争和提高效率;工作模式为低损耗的TE02/TE03模式,有利于连续波工作。通过对回旋管中谐振腔结构、模式竞争以及注—波互作用的研究,分析了高频结构特性、寄生模式的抑制和工作参数优化等问题,给出了模拟设计结果。

A 3 mm low-voltage second-harmonic complex cavity gyrotron with gradual transition is designed and evaluated with a particle-in-cell code. The high efficient gyrotron interaction can be achieved at the second harmonic. The insulation requirements of the gyrotron and the size and weight of the power supply can be reduced by setting the operation voltage at 25 kV. A diffraction-coupled complex cavity operating in the low ohmic loss TEo2/TE03 circular modes is introduced to control the mode competition problem and promote efficiency. The characteristics of RF structure, the suppression of parasite oscillations, and the optimization of work parameters are discussed. The PIC simulation results show that the gyrotron can generate 34 kW output power at 94 GHz with 34% operation efficiency.