用于小型AMS的类布拉格探测器研制  

Development of A Bragg-like Detector for Miniaturized AMS

作　　者：修诚利 张文慧[1] 赵庆章[1] 何明[1] 包轶文[1] 李康宁[1] 郭巍 董鹏伟 XIU Chengli;ZHANG Wenhui;ZHAO Qingzhang;He Ming;BAO Yiwen;LI Kangning;GUO Wei;DONG Pengwei(China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《核电子学与探测技术》2024年第2期277-283,共7页Nuclear Electronics & Detection Technology

基　　金：国防科工局核能开发项目(FA202312-000201)。

摘　　要：为了解决小型AMS系统中,使用现有的气体电离室探测低能量重粒子时,脉冲信号高度与探测器本底噪声重合较多、难以有效区分的问题,研制了一种新型的类布拉格气体电离室。在一定的约化场强下,这种电离室能够使电子在阳极附近区域发生电子倍增,从而使脉冲信号高度上升,以达到与探测器本底噪声分开的目的。利用5.8 MeV的α粒子进行实验,通过调节α粒子进入探测器的能量,并在不同气体压力、阳极电压(约化场强E/P)的条件下对探测器性能进行系统调试。经过模拟计算和系统调试,得出以下结论:该探测器可用于测量粒子的能谱,能量分辨率可达到2.98%。当阳极前1 mm处的约化场强E/P为5 V·mm^(-1)·hPa^(-1)时,脉冲信号的增益大约为7倍。In order to address the issue of significant overlap between the pulse signal height and the background noise of the detector in the detection of low-energy heavy particles using existing gas ionization chambers in miniaturized AMS systems,a new Bragg-like gas ionization chamber was developed.Under a certain reduced field strength,this ionization chamber enables electron multiplication in the vicinity of the anode,resulting in an increase in pulse signal height and effective separation from the detector background noise.Experimental measurements were conducted using 5.8 MeV alpha particles,with adjustments made to the energy of alpha particles entering the detector and systematic calibration of detector performance under different gas pressures and anode voltages(reduced field strength E/P).Through simulation calculations and system calibration,the following conclusions were drawn:the detector is suitable for energy spectrum measurement of particles,achieving an energy resolution of 2.98%.When the reduced field strength E/P at the front of the anode is approximately 5 Vmm-1hPa-1,the pulse signal gain is approximately 7 times.

关 键 词：小型AMS 气体电离室 类布拉格探测器 电子倍增 

分 类 号：TL811[核科学技术—核技术及应用]