一种磁控管用W-Y合金阴极热发射特性研究  

Thermionic Emission Characteristics of Novel W-Y Alloy Cathode of High-Power Magnetron Tube

作　　者：漆世锴 曾伟 张敏[2] 王小霞[3] 胡明玮 Qi Shikai;Zeng Wei;Zhang Min;Wang Xiaoxia;Hu Mingwei(College of Electric Engineering, Jiujiang University ,Jiujiang 332005, China;Beijing Vacuum Electronics Research Institute, Beijing 100016, China;Key Laboratory of High Power Microwave Sources and Technologies, Institute of Electronics, Chinese Academy of Sciences ,Beijing 100190 ,China;School of Physics and Optoeletronic Engineering, Xidian University, Xi＇an 710071, China)

机构地区：[1]九江学院电子工程学院,九江332005 [2]北京真空电子技术研究所,北京100015 [3]中国科学院电子学研究所中国科学院高功率微波源与技术重点实验室,北京100190 [4]西安电子科技大学物理与光电工程学院,西安710071

出　　处：《真空科学与技术学报》2017年第11期1056-1061,共6页Chinese Journal of Vacuum Science and Technology

基　　金：军委装备发展部科研订购局预研领域基金(批准号:6140862010106)

摘　　要：研制了一种大功率磁控管用W-Y合金阴极,并对该合金阴极的热发射、寿命等特性分别进行了测试。热发射测试结果显示,该合金阴极在1400℃工作温度时,其直流热发射特性曲线出现了较明显的空间电荷偏离点。而当阴极工作温度升高为1500℃、1600℃时,该阴极的直流热发射特性曲线一直呈直线上升,并未出现空间电荷偏离点,这与金属阴极的热发射特性曲线一般会出现空间电荷偏离点常识相违背。寿命测试结果显示,该合金阴极在1600℃工作温度下,经过80 h寿命测试后,热发射电流密度从初始的1.5直线下降至0.2 A/cm^2,能谱仪分析结果显示,此时W-Y合金阴极中Y元素从初始的46.45%下降至8.36%。最后,对该合金阴极热发射反常现象机理进行了有益的探讨。A novel type of the W-Y cathode,compressing W-filament surface-modified with W-Y alloy coating synthesized via powder metallurgy,has been developed for the high power magnetron tube. The impact of the W-Y coatings on the DC thermionic emission characteristics and lifetime of the new cathode was investigated with scanning electron microscopy and energy dispersive spectroscopy. The preliminary results show that the well-defined space charge deviation point at 1400℃,as regularly observed in the thermionic emission curves of all conventional metal cathodes,vanished at 1500℃ and/or 1600℃,possibly because of the Y evaporation and because of the plasma layer formation near the W-Y alloy surfaces. T ested at 1600℃ for 80 h,the emission current density decreased from 1. 5 down to 0. 2 A/cm^2,accompanied by a Y-content reduction from 46. 45% to 8. 36% in the W-Y alloy coating.

关 键 词：合金阴极 热电子发射 磁控管 发射机理 等离子体 

分 类 号：O462[理学—电子物理学]