行波管用阴极表面黑斑现象的电子显微分析  

Electronic microanalysis of black spots on the cathode surface used in travelling-wave tube

作　　者：李鹏[1] 包生祥[1] 张德政[1] 史光华[1] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,四川成都610054

出　　处：《真空》2011年第5期29-31,共3页Vacuum

基　　金：国防科工委共性项目

摘　　要：针对行波管用阴极表面异常的黑斑现象,利用扫描电镜(SEM)和X射线能谱仪(EDS)对阴极的不同微区进行了对比分析,查找黑斑产生的原因,并对其对阴极发射性能造成的影响进行了探讨。结果表明,行波管内真空度下降,阴极中的发射物质与空气中的水汽和氧气反应,随着工作时间的延长,最终导致黑斑的出现。黑斑的出现严重影响阴极的发射性能,这对行波管的封装可靠性提出了较高的要求。Aiming at the abnormal black spots on the surface of cathode used in travelling-wave tube （TWT）, different micro-areas of the cathode were analyzed by scanning electron microscopy （SEM） and X-ray energy spectrometer （EDS）. The causes of the black spots were found, and its impact on the cathode emission properties was also discussed. The results revealed that the cathode emissions will react with water vapor and oxygen in air when the vacuum is not high enough in TWT. Dark spots eventually appear with the extension of working time, which will seriously affect the cathode emission properties. It means that the reliability of packaging process for TWT is strictly required.

关 键 词：阴极 黑斑 扫描电镜 能谱仪 

分 类 号：O552[理学—热学与物质分子运动论] TB716[理学—物理]