行波管电子枪热分析与结构优化设计

Thermal analysis and structural optimization of electron gun for traveling wave tube

利用ANSYS软件建立某Ka波段行波管2mm阴极电子枪的有限元模型,并进行稳态及瞬态热分析,提取热流矢量图与温度分布图,得到阴极稳态时的温度分布及预热时间。对电子枪样品进行实验测试,得到的实测温度与模拟温度相差2%,因而在误差允许的范围内有限元方法是可行的。根据热流矢量图对热屏蔽筒进行结构优化,优化后,阴极温度比优化前提高了28℃,整枪最高温度提高了27℃,阴极预热时间缩短了40s,缩短幅度达到33%。优化后的结构较大程度地提高了阴极的快启动性能,提升了行波管的快速反应能力。

Steady-state and transient thermal analysis of electron gun for a Ka-band traveling wave tube are theoretically performed with a newly-developed 2 mm cathode model by ANSYS software.The heat flux vector chart and temperature distribution chart as well as warm-up time are also derived.The discrepancy of 2% between simulation results and test results,proves that the finite element method is feasible.The ultimate temperature reached by cathode,at given heater power,remarkably depends on the thermal conduction mechanism through cathode module.Based on the heat flux vector chart,the structure of cathode support sleeve with the highest heat flux is optimized.After optimization,the temperature of cathode increases 28 ℃,the highest temperature of electron gun increases 27 ℃ and the warm-up time of cathode reduces 40 s under the same given heater power.The optimized structure can effectively shorten the warm-up time of cathode by 33% and thus improve fast warm-up the performance of cathode,enhancing the rapid response capability of traveling wave tube.