220 GHz回旋管模式竞争分析和数值模拟

当回旋管的工作频率提高时，为了增大腔体的半径，通常选择高次模式作为工作模式，这时回旋管中可能存在模式竞争，该文采用线性理论及多模非线性理论分析了所设计的220 GHz回旋管振荡器中的模式竞争问题。编制了起振电流和多模非线性注波互作用计算程序，通过数值模拟计算出每个模式的输出功率对时间的变化情况，验证了回旋管中可能存在的3种平衡状态，证实了设计的合理性。

Mode Competition Analysis and Simulation of 220 GHz Gyrotron

In high frequency, the high-order waveguide mode is usually employed to increase the size of resonant cavity of gyrotron, but the problem of mode competition could be caused in this case. In this paper, linear and nonlinear multimode theories are employed to analyze the mode competition of the 220 GHz gyrotron oscillator we designed. The starting current and characteristics of beam-wave interaction of the oscillator are calculated, the output power of modes is obtained through numerical simulation. The results show that there are three balanceable states in the gyrotron and the design of 220GHz gyrotron is reasonable.