吕昕平2,
任峰1,
卢志鹏1, 2,
王欣欣1,
王宇1,
邯娇1,
张琪1,
李阳1
1.中国科学院空天信息创新研究院高功率微波源与技术重点实验室 北京 100190
2.中国科学院大学 北京 100049
基金项目:国家重点研发计划(2018YFB1105200)
详细信息
作者简介:阴生毅:男,1964年生,研究员,研究方向为大电流密度阴极及其发射机理
吕昕平:男,1997年生,硕士生,研究方向为液相合成法制取新型高活性电子发射材料
任峰:男,1992年生,助理研究员,研究方向为热电子发射材料及其制备
卢志鹏:男,1993年生,博士生,研究方向为大电流密度阴极技术及覆膜阴极技术
王欣欣:女,1986年生,中级工程师,研究方向为覆膜浸渍阴极
王宇:男,1981年生,工程师,研究方向为覆膜阴极制备工艺
邯娇:女,1986年生,中级工程师,研究方向为阴极热子制备工艺
张琪:男,1982年生,工程师,研究方向为热阴极精加工技术
李阳:男,1990年生,工程师,研究方向为热阴极制备技术
通讯作者:阴生毅 ysy210@163.com
中图分类号:O462.1计量
文章访问数:158
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被引次数:0
出版历程
收稿日期:2021-01-21
修回日期:2021-04-19
网络出版日期:2021-05-07
刊出日期:2021-10-18
Experimental Study and Theoretical Model for Increasing the Current Density of Thermionic Cathodes through Active Impregnant Substance
Shengyi YIN1,,,Xinping Lü2,
Feng REN1,
Zhipeng LU1, 2,
Xinxin WANG1,
Yu WANG1,
Jiao HAN1,
Qi ZHANG1,
Yang LI1
1. Key Laboratory of High Power Microwave Sources and Technologies, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
Funds:National Key R&D Program of China (2018YFB1105200)
摘要
摘要:通过发展新的活性物质成分系统及其制备方法以提升钪系阴极的电子发射性能,是当今热阴极特别是大电流密度阴极领域的研究重点。该文提出一种由多元金属氧化物构成的新型高活性浸渍物质,显著提升了钪在阴极中的添加比例,大幅提高了阴极的发射电流密度。将冷冻干燥法应用到该活性物质前驱体的制备过程中,有效解决了传统固相合成方法在机械式破碎、研磨和混合等工序中存在的不可控、不均匀等问题。采用了新的成分系统与新的制备方法制得活性物质的阴极,在真空二极管测试和电子枪测试中分别取得了超过500 A/cm2和218.5 A/cm2的脉冲发射电流密度。在二极管直流测试条件下,阴极的寿命测试进行了10500 h后仍未出现发射电流下降的现象;而在电子枪中的大工作比(5%)脉冲测试条件下,阴极在工作了2010 h后仍维持了超过50 A/cm2的较大发射电流密度。借助深紫外—光/热发射电子显微镜(DUV-PEEM/TEEM)分析发现,相较传统的钪系阴极,新制备的大电流密度阴极表面的热电子发射位点数量增加,微区发射面积显著增大。最后,提出一种“二叉树”发射模型,以期阐释钪系阴极采用新活性物质后获得高发射特性的物理机制。
关键词:浸渍扩散阴极/
电子发射/
液相合成法/
冷冻干燥法
Abstract:Developing new active substance composition system and its preparation method to enhance scandate cathode’s emission property is a hotspot in the research field of thermionic cathode especially high-emission cathode. A novel highly active impregnant substance consisting of polymetallic oxide which apparently increases scandium’s appending proportion and greatly enhances cathode’s emission current density is put forward in this paper. Freeze-drying method is applied into preparation of the active substance’s precursor and effectively solves the problem of inhomogeneity and uncontrollability in the mechanical crushing, grinding and mixing procedures of conventional solid-phase synthesis routine. Cathode which adopted novel composition system and substance acquired by new preparation routine reaches a pulse emission current density of above 500 A/cm2 under close-spaced diode configuration and 218.5 A/cm2 in an electron gun. Under the DC diode experimental configuration, the cathodes’ emission lifetime test has endured for 10500 hours with no emission current drop; while in the electron gun with a pulse drive of heavy duty cycle (5%), the cathode maintains a big workload of more than 50 A/cm2 after having worked for 2010 hours. Via Deep UltraViolet laser-Photo Emission and Thermal Emission Electron Microscopy (DUV-PEEM/TEEM) analyzation, the phenomenon ofthermionic emission points’ amount increases and emitting micro-area expands on the newly prepared high-emission cathode’s surface is observed. Finally, a ‘binary tree’ emission model is brought up, hoping to explain the physical mechanism of scandate cathode’s high emission character with new active substance.
Key words:Impregnated dispenser cathode/
Electron emission/
Liquid phase synthesis/
Freeze-drying method
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