南方先进光源C波段光阴极电子枪微波设计  

RF design of C-band photocathode electron gun for Southern Advanced Photon Source

作　　者：刘盛进[1,2] 姜世民 刘星光 肖永川 曹秀霞[1,2] 吕永佳 李晓[1,2] Liu Shengjin;Jiang Shimin;Liu Xingguang;Xiao Yongchuan;Cao Xiuxia;LüYongjia;Li Xiao(Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;Spallation Neutron Source Science Center,Dongguan 523803,China)

机构地区：[1]中国科学院高能物理研究所,北京100049 [2]散裂中子科学中心,广东东莞523803

出　　处：《强激光与粒子束》2025年第1期162-168,共7页High Power Laser and Particle Beams

基　　金：国家自然科学基金面上项目(11875271);中国科学院高能物理研究所创新项目(E3545AU2)。

摘　　要：作为南方先进光源直线段注入器重要设备,开展了C波段光阴极电子枪研究,包括驻波腔微波设计和耦合器设计。其中驻波腔采用3.6腔结构,π模加速模式,工作频率为5.712 GHz;耦合器采用同轴耦合方式。利用Superfish及CST完成了腔体微波结构设计,优化盘片的形状,降低腔体表面最大电场,从而有利于提高腔体加速场强;利用COMSOL开展了腔体水冷系统的分析,优化设计水路,减少腔体由于功率负载所造成的频率偏移,控制腔体温度的上升,保持腔体最大温升小于20℃。在18.15 MW的入腔功率下,阴极面最高场强为180 MV/m,腔体表面最大场强与阴极面场强比值约为0.934 6,腔体Q值大于10 000。通过对耦合器的设计,抑制二极模和四极模的传输,S_(11)参数小于-40 dB。The C-band photocathode electron gun is designed.As one of important equipments for the linear injector of the Southern Advanced Photon Source.This paper discusses its RF and coupler design.The C-band electron gun has a working frequency of 5.712 GHz,a 3.6-cell structure,aπ-mode acceleration mode,and it adopts a coaxial coupling method.The CST and Superfish codes are used to optimize the cavity microwave structure,reducing the surface electric field of the cavity to enhance the accelerating field strength and suppressing the multimode transmission.Furthermore,COMSOL Multiphysics is applied to analyze the cavity cooling system,reducing frequency drift caused by the cavity heating.Additionally,a water cooling design for the cavity ensures that the maximum temperature rise of the cavity is less than 20℃.Under an input power of 18.15 MW,the acceleration gradient of 180 MV/m on the cathode surface is achieved,the ratio of the acceleration gradient to the cathode surface electric field is approximately 0.93,and the cavity quality factor is greater than 10000.The design of the coupler suppresses the transmission of dipole and quadrupole modes,with the S_(11) parameter being less than-40 dB.

关 键 词：南方先进光源 光阴极电子枪 微波结构 耦合器 C波段 

分 类 号：TL503.2[核科学技术—核技术及应用]