Optimization of the cavity beam-position monitor system for the Shanghai soft X-ray free-electron laser user facility

作     者：Jian Chen Yong-Bin Leng Lu-Yang Yu Long-Wei Lai Ren-Xian Yuan Jian Chen;Yong-Bin Leng;Lu-Yang Yu;Long-Wei Lai;Ren-Xian Yuan

作者机构：Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China 

出 版 物：《Nuclear Science and Techniques》 (核技术（英文）)

年 卷 期：2022年第33卷第10期

页      面：22-32页

核心收录：

学科分类：080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 0803[工学-光学工程] 

基　　金：supported by the National Key Research and Development Program of China(No.2016YFA0401903) National Natural Science Foundation of China(No.12175293) the Young and Middle-Aged Leading Scientists Engineers and Innovators through the Ten Thousand Talent Program 

主　　题：Cavity BPM SXFEL System optimization Position resolution Measurement uncertainty Algorithm 

摘      要：To achieve high-efficiency operation of the highgain free-electron laser(FEL),the electron beams and radiated photon beams need to be overlapped precisely and pass through the entire undulator ***,a high-resolution beam-position monitor(BPM)is required.A cavity BPM(CBPM)with a resonant cavity structure was developed and used in the Shanghai Soft X-ray FEL(SXFEL)test facility and can achieve a position resolution of1μ*** construction and operation of the SXFEL user facility also bring about higher requirements for beamposition *** this case,the factors that affect the performance of the CBPM system were further *** included the amplitude and phase stability of the local oscillator,stability of the trigger signal,performance of the radio frequency front-end,signal processing electronics,and signal processing *** on the upgrade and optimization of the system,a beam test platform was built at the end of the linear acceleration section of the SXFEL,and the experimental results show that the position resolution of the system can reach 177 nm at a bunch charge of 500 pC,and the dynamic range is controlled within±300μm,and the relative measurement uncertainty of the bunch charge can reach 0.021%,which are significant improvements compared to the attributes of the previous system.