140 GHz折叠波导行波管电子光学系统设计与验证

Design and verification of electron optical system for 140 GHz folded waveguide travelling wave tube

摘要: 设计了一种140 GHz折叠波导行波管电子光学系统，利用三维粒子仿真软件Opera-3D对考虑热初速效应的圆形电子注在周期永磁聚焦系统内传输状态进行了仿真分析，并对磁场过渡区进行了优化设计，改善电子注与磁场的匹配效果。经计算，该电子光学系统阴极发射电流60 mA，阴极电压20 kV，流通率99.9%。样管测试结果显示，电子枪参数与设计结果相符合，实测流通率达到97.2%，行波管实现连续波稳定工作。

Abstract: In this paper, the electron optical system for 140 GHz folded waveguide travelling wave tube (FTWT) is designed. The electron beam considering the thermal velocity effect in periodic permanent magnetic (PPM) focusing system is simulated and optimized by using the particle simulation software Opera-3D. The magnetic field is optimized to improve the matching effect between electron beam and PPM. The current of electron optical system is 60 mA when the anode voltage is 20 kV, and the simulation shows that the transmission efficiency is improved to 99.9%. In the experiment of sample tube, the parameters of the electron gun are in agreement with the design results. When the travelling wave tube (TWT) works in DC mode, about 97.2% of the electron beam reaches the collector.