高功率微波源用电子收集极材料:强流高能电子束轰击下的物理效应及对材料性能的要求

高功率微波源用收集极用于接收束波耦合作用后的强流电子束,是影响高功率微波源稳定性和寿命的关键部件。收集极在强流电子束的轰击下会产生二次电子、背散射电子、韧致辐射等物理效应,将引起微波品质的降低。电子束的能量沉积在收集极上会产生显著的温升效应,从而导致收集极效能下降甚至结构失效,同时材料在强流电子束的轰击下会发生蒸发而污染腔室,降低系统绝缘性。在讨论分析强流电子束轰击材料所产生的物理效应机制及其影响因素的基础上,分析了高功率微波源用收集极材料的性能要求。

Electron Collector Materials for High-power Microwave Source:High-current Relativistic Electron Beam Bombardment-induced Physical Effects and Relevant Performance Requirements

Collector of high-power microwave source is a key component which influences the stability and lifetime of the high-power microwave system.The physical effects rose from collector bombarded by high-current electron beam, such as secondary electrons, back scattered electrons, and Bremsstrahlung radiation, which consequently lead to quality decline of the generated microwave.The substantial temperature rise induced by continuous concentration of electron beam energy upon electron collector will result in invalidation or even structural failure of the collector.Moreover, high-current relativistic electron beam bombardment also causes material′s partial evaporation and subsequently, pollution of the vacuum chamber.In this paper, the physical effects rose from the material bombarded by high-current electron beam are discussed, with which requirements for both properties and materials of collector for high-power microwave source are proposed.