兰州高能电子成像实验平台电子束团长度测量研究  

Study on Electron Bunch Length Measurement of Lanzhou High Energy Electron Radiography Experimental Platform

作　　者：艾蕾 赵全堂[2,3] 宗阳 冉朝晖[2] 袁肖肖 曹树春 李佳[2,3] 申晓康 赵书俊 张子民[2,3] AI Lei;ZHAO Quantang;ZONG Yang;RAN Zhaohui;YUAN Xiaoxiao;CAO Shuchun;LI Jia;SHEN Xiaokang;ZHAO Shujun;ZHANG Zimin(College of Physics,Zhengzhou University,Zhengzhou 450000,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;School of Nuclear Science and Technology,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]郑州大学物理学院,河南郑州450000 [2]中国科学院近代物理研究所,甘肃兰州730000 [3]中国科学院大学核科学与技术学院,北京100049

出　　处：《原子能科学技术》2022年第3期570-576,共7页Atomic Energy Science and Technology

摘　　要：为提高高能电子成像的时间和空间分辨率,实验需低能散、低发射度、短脉冲的高品质束流。本文利用相干渡越辐射能谱分析法测量基于热阴极微波电子枪的高能电子成像用直线加速器的电子束团长度。通过用迈克尔逊干涉仪测量太赫兹辐射能谱,利用自相关曲线拟合法得到电子束团长度。实验结果表明,当束流宏脉冲峰值强度约为24 mA,即电荷量约为15 pC时,电子束团均方根长度约为0.7235 ps。另外,用Kramers-Kronig(K-K)相位分析法可重建一种可能的电子束团纵向分布。电子束团长度测量的研究可优化束流品质,对后续高能电子成像实验有重要的参考意义。In order to improve the temporal and spatial resolution of high energy electron radiography(HEER),high quality electron beam with low energy spread,low emittance and short pulse length is required for the experiment.In this paper,the electron bunch length was measured by a method based on analysis of the coherent transition radiation energy spectrum.The linac for HEER is based on the thermionic cathode RF gun.The energy spectrum of the terahertz radiation was measured by Michelson interferometer.The electron bunch length was obtained by auto-correlated curve fitting method.The experimental result show that when the macro-pulse bunch peak current is about 24 mA(the bunch charge about 15 pC),the root mean square(RMS)bunch length is about 0.7235 ps.Furthermore,the Kramers-Kronig(K-K)phase analysis method can be used to reconstruct a possible electron bunch longitudinal distribution.The study of electron bunch length measurement can be used to optimize the electron beam quality and there is great reference significance for subsequent HEER experiments.

关 键 词：超短电子束团 迈克尔逊干涉仪 相干渡越辐射 太赫兹 

分 类 号：TL53[核科学技术—核技术及应用]