Emission characteristics of Ba-W dispenser cathode doped with spray-dried nano-sized scandia

被引：0
|
作者：
Zhu, Xiaoce [1 ]
Wang, Yiman [1 ]
Liu, Wei [1 ]
Yang, Fan [1 ]
Wang, Jinshu [1 ]
机构：
[1] School of Materials Science and Engineering, Beijing University of Technology, Beijing
来源：
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | 2015年 / 35卷 / 12期
关键词：
Scandate cathodes; Spray-drying; Thermionic emission; Vacuum electron devices;
D O I：
10.13922/j.cnki.cjovst.2015.12.06
中图分类号：
学科分类号：
摘要：
A novel type of Ba-W dispenser cathodewas fabricatedby spray-drying of W pellets, pre-doped with nano-sized scandia (Sc2O3) and impregnated in Ba-and Ca-aluminates. The impact of the fabrication conditions on the microstructures and emission properties of the novel dispenser cathode was investigated with scanning electron microscopy. The tested results show that the new highly porous, Sc2O3-doped cathode outperforms the conventional ones fabricated by solid-liquid reaction and sol-gel techniques because of its better performance and longer lifetime. To be specific, at 950℃, thespace charge limited DC current density, in closely-spaced diodes, was over 60 A/cm2, after temperature compensation for electron cooling;and the stable DC current density of 30 A/cm2 at 950℃ had lasted for longer than 3000 h. In Pierce electron-gun tests, initiated at 58 A/cm2, the knee-point temperature was 900℃ and the cathode worked fairly well for over 1000 h with a pulsed current density of 50 A/cm2. © 2015, Science Press. All right reserved.
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页码：1431 / 1436
页数：5
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