基于LaB6光电阴极的光触发赝火花电子束源实验研究  

Design and Properties of Cu-Based LaB6 Photocathode for Pseudospark Discharge in Electron Beam Source:An Experimental Study

作　　者：霍卫杰 胡静[1] 曹晓彤 傅宇蕾 赵万生[1] Huo Weijie;Hu Jing;Cao Xiaotong;Fu Yulei;Zhao Wansheng(School of Mechanical Engineering,Shanghai Jiaotong University,Shanghai 200240,China)

机构地区：[1]上海交通大学机械与动力工程学院

出　　处：《真空科学与技术学报》2019年第8期631-636,共6页Chinese Journal of Vacuum Science and Technology

摘　　要：以改善空心阴极放电的性能,提高放电产生的电子束为目标,设计了光触发多电极赝火花放电腔装置。光触发用的光电阴极材料选取低功函数的LaB6材料,并以Cu为基底材料加工制作了赝火花放电装置中的核心部件--空心阴极腔。光触发放电实验结果显示,LaB6阴极提高了赝火花光触发模式下放电的稳定性和可控性。电子束测量结果表明,相同放电电压下,LaB6阴极中产生的电子束束流峰值与同等实验条件下的Cu阴极相比,提高了53.6%~92%;而与此同时,电子束的半高宽只改变了10.7%~18.2%。本论文中的实验结果证实了LaB6作为触发材料能够有效的加强空心阴极腔内的气体电离,从而改善光触发放电的性能。LaB6作为阴极腔材料,促进了空心阴极腔和极间的等离子体形成和发展,显著提高了放电所产生的电子束电流密度,同时并未引入过多的能量损耗过程和低速低能量电子。A novel pseudo-spark discharge device was designed to optically trigger the multi-gap pseudo-spark and generate electron beam.The original work was the Cu-based LaB6 photocathode.The influence of the Cu-based LaB6 photocathode on the e-beam behavior was investigated.The results show that the Cu-based LaB6 photocathode significantly improves the controllability and stability of the optical trigger discharge.When it comes to properties of e-beam induced by pseudo-spark discharge,the Cu-based LaB6 photocathode outperforms conventional Cu-cathode.For example,the peak e-beam current for Cu-based LaB6 photocathode was 0.7 A,0.3 A higher than that for Cu-cathode(0.4 A),increasing by 76.2%.The increase of e-beam pulse duration was roughly 10.7%~18.2%.We suggest that LaB6 be a good photoelectric material for optical triggering pseudo-spark discharge because it considerably increases e-beam current density,promotes formation and growth of plasma,produces little low energy electrons and does not generate much energy loss.

关 键 词：光触发 光电阴极 LaB6 赝火花电子束 空心阴极放电 

分 类 号：TN14[电子电信—物理电子学] O462.3[理学—电子物理学]