砷化镓光阴极直流高压注入器研究进展  

Recent progress of GaAs high-voltage DC photo-injector

作　　者：吴岱[1] 肖德鑫[1] 李凯[1] 潘清[1] 杨仁俊[1] 张海旸[1] 王建新[1] 刘宇[1] 柏伟[1] 林司芬[1] 王汉斌[1] 杨兴繁[1] 黎明[1] 许州[1] 

机构地区：[1]中国工程物理研究院应用电子学研究所,四川绵阳621900

出　　处：《强激光与粒子束》2015年第4期232-237,共6页High Power Laser and Particle Beams

基　　金：国家重大科学仪器设备开发专项(2011YQ130018);国家自然科学基金项目(11305165;11475159);中国工程物理研究院发展基金项目(2011B0402070;2013B0401073;2014B0402069;2014B0402070)

摘　　要：主要介绍自由电子激光相干强太赫兹源(FEL-THz)装置上的砷化镓光阴极直流高压注入器的研究进展,并讨论其驱动未来高重复频率短波长自由电子激光器的差距。通过综合砷化镓阴极寿命的三大影响因素,提出了其工作寿命的定性物理模型;通过该模型对阴极和注入器进行优化,在直流高压电子枪上得到了5mA,32min的连续稳定输出;测量了电子束在4.8mA下归一化发射度约为4.0πmm·mrad,阴极热发射度约为0.6πmm·mrad,电子束本征横向能量约为92meV,250keV电子束在距离阴极90.6cm处纵向均方根长度约为11.5ps。这一束流状态已经基本满足FEL-THz需求。The GaAs photocathode high-voltage DC injector has been demonstrated as one of the most important electron sources for future high-repetition short-wave free electron lasers（FELs）and energy recovery linacs（ERLs）.In this paper,recent progress of the GaAs high-voltage（HV）photo-injector for the FEL-THz facility is presented,and the chance of which for driving a future high-repetition short-wave FEL is discussed.All the factors that affect the GaAs photocathode operation life-time are considered and a qualitative physical model is proposed.Under the guidance of this model and with some optimization strategies,a 5mA/32 min CW output is reached in the HV DC injector.Some electron beam parameters are measured,including normalized emittance under 4.8mA output that is about 6.0πmm·mrad,thermal emittance about 0.6πmm·mrad,intrinsic transverse energy about 92 meV,and root-mean-squared length with 250 keV kinetic energy that is 11.5ps at 90.6cm after the cathode.The state of the injector now meets the needs of FEL-THz electron source requirements preliminarily.

关 键 词：高重复频率短波长自由电子激光 砷化镓光阴极 直流高压电子枪 阴极工作寿命 电子束参数测量 

分 类 号：TL53[核科学技术—核技术及应用] O462.3[理学—电子物理学]