碳纤维复合石墨阴极的制备及电子发射性能  

Preparation and electron emission properties of carbon fiber composited graphite cathodes

作　　者：方东 华叶 王震 龚瑾瑜 万红[1] FANG Dong;HUA Ye;WANG Zhen;GONG Jinyu;WAN Hong(College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China;Key Laboratory of Advanced HPM Technology,Northwest Institute of Nuclear Technology,Xi’an 710024,China)

机构地区：[1]国防科技大学空天科学学院,长沙410073 [2]西北核技术研究所先进高功率微波技术重点实验室,西安710024

出　　处：《材料工程》2023年第8期149-154,共6页Journal of Materials Engineering

摘　　要：阴极作为强流电子束的起点,对高功率微波源的性能具有重要影响。石墨是高功率源用爆炸发射阴极的常用材料,具有高压重频条件下运行稳定和长寿命的优点。使用具有高长径比、低发射阈值的碳纤维对石墨阴极进行复合,采用场发射及高功率微波测试平台,对比分析纯石墨阴极及碳纤维复合石墨阴极的场发射性能、强流电子发射性能及输出微波特性,结合阴极的微观结构表征,研究碳纤维复合对石墨阴极电子发射性能的影响规律。研究表明:与鳞片石墨阴极相比,40%(质量分数)碳纤维复合石墨阴极的场发射阈值电场由143 kV/cm降低到119 kV/cm,降低了约16.8%,二极管电压为480 kV时输出的微波脉宽与峰值分别提高了13.5%,5.7%。同时考虑到碳纤维在爆炸电子发射过程中结构稳定性的特点,碳纤维的复合也有利于阴极使用寿命的提高。As the source of intense electron beam,the cathodes have an important effect on the performance of high power microwave source.Graphite is a common material for explosive emission cathodes of high power microwave source,which have the advantages of stable operation and long life under high pressure and repetition frequency.The carbon fiber with high aspect ratio and low emission threshold was chosen to be composited with the graphite cathode,and the field emission and high power microwave test platforms were adopted to analyse field emission properties,intense electron emission performances and output microwave characteristics of pure graphite cathodes and carbon fiber composited graphite cathodes.Meanwhile the effect of carbon fiber on the electron emission properties of graphite cathodes was studied combined with the microstructure characterization of the cathodes.The results show that compared with the flake graphite cathodes,the field emission threshold of 40%(mass fraction)carbon fiber composited graphite cathodes decreases from 143 kV/cm to 119 kV/cm,a reduction of about 16.8%,and the output pulse width and peak of 480 kV increase by 13.5%and 5.7%,respectively.Considering the structural stability of carbon-fiber in the process of explosive electron emission,the carbon-fiber is also beneficial for improving the service life of the cathodes.

关 键 词：高功率微波源 石墨阴极 碳纤维复合 场发射 

分 类 号：TB34[一般工业技术—材料科学与工程]