M型扩散阴极用新型含锶低蒸散发射活性材料  

Thermal Evaporation/Emission Properties of Sr-Doped Emission Active Coatings of M-Type Cathode

作　　者：李娜[1] 于志强[1] 高玉娟[1] Li Na;Yu Zhiqiang;Gao Yujuan(12^(th)Research Institute of China Electronic Technology Corporation,Beijing 100015,China)

机构地区：[1]中国电子科技集团公司第十二研究所,北京100015

出　　处：《真空科学与技术学报》2020年第12期1202-1207,共6页Chinese Journal of Vacuum Science and Technology

摘　　要：聚焦真空器件用M型(Magic)阴极的蒸发性能,采用共沉淀法将Sr元素掺入阴极发射活性材料中,研究发射活性材料成分差异对阴极蒸发性能及发射性能的影响。研究结果显示,相同的制备及测试条件下,浸渍了新型含锶发射活性材料的M型阴极的蒸发速率显著下降,两种新型发射活性材料(AM1#和AM2#)浸渍的阴极样品的蒸发率在1060℃测试时,较常规阴极的蒸发率分别下降了49.95%和71.87%;在1100℃测试时,蒸发率与常规M型阴极相比,分别下降了40.27%和61.45%,与此同时,两种含锶的新型阴极发射电流密度仍能保持较高水平。Sr元素的掺入量对阴极的蒸发性能和发射性能均有明显影响,阴极样品的活性材料蒸发率和脉冲发射电流密度均随Sr含量的升高而降低。The thermal emission properties of self-developed M-type cathode,an advanced space vacuum electronic devices(VEDs)and fabricated with the Sr-doped conventional emission active coatings deposited by impregnation,were characterized with X-ray diffraction and pulsed emission and evaporation tests.The influence of the Sr-content on the thermal evaporation and emission rates was investigated with AM1#/AM2#samples comprised BaAl_(2)O_(4),SrAl_(12)O_(19),Ba_(3)Al_(2)O_(6),CaAl_(2)O_(4) and BaAl_(2)O_(4),Sr_(3)Al_(2)O_(6),Ca_(5)(Al_(3)O_(7))2,Ba3CaAl2O7,respectively.The results show that the Sr-doping matters.Specifically,measured at 1060℃,the evaporation-rates of AM1#and AM2#samples decreased by 49.95%and 71.87%,respectively;and evaluated at 1100℃,the evaporation rates were 40.27%and 61.45%lower than that of conventional dispenser cathode,respectively.As the Sr-content increased the pulsed emission current density and thermal evaporation rates decreased.However,the decreased emission rate of Sr-doped M-type cathode still meets the stringent requirements of VEDs.

关 键 词：M型阴极 发射活性材料 锶 贝克法 蒸发率 

分 类 号：O462[理学—电子物理学] TN104[理学—物理]