Bunch length measurement using a traveling wave RF deflector

作     者：ZHANG Jing-Ru DAI Jian-Ping GU Qiang PEI Guo Xi ZHAO Ming-Hua ZHONG Shao-Peng WANG Xing-Tao CHEN Yong-hong HOU Mi 张敬如;戴建枰;顾强;裴国玺;赵明华;钟少鹏;王兴涛;陈永忠;侯汨

作者机构：Institute of High Energy Physics CAS Graduate University of Chinese Academy of Sciences Shanghai Institute of Applied Physics CAS 

出 版 物：《Chinese Physics C》 (中国物理C（英文版）)

年 卷 期：2010年第34卷第1期

页      面：138-142页

核心收录：

学科分类：07[理学] 070202[理学-粒子物理与原子核物理] 0702[理学-物理学] 

基　　金：Supported by Major State Research Development Program (2002CB713606) 

主　　题：RF deflector bunch length RF gun HEM11 mode 

摘      要：RF deflectors can be used for bunch length measurement with high resolution. This paper describes a completed S-band traveling wave RF deflector and the bunch length measurement of the electron beam produced by the photocathode RF gun of the Shanghai DUV-FEL facility. This is the first time that such a transverse RF deflector has been developed and used to measure the bunch length of picosecond order in China. The deflector＇s VSWR is 1.06, the whole attenuation 0.5 dB, and the bandwidth 4.77 MHz for VSWR less than 1.1. With a laser pulse width of 8.5 ps, beam energy of 4.2 MeV, and bunch charge of 0.64 nC, the bunch lengths for different RF input power into the deflector were measured, and an averaged rms bunch length of 5.25 ps was obtained. A YAG crystal is used as a screen downstream of the deflector, with the calibrated value of 1 pix = 136 μm.