一种具有射程鉴别能力的气体探测器研制  

Development of a Gas Detector with Range Discrimination Capability

作　　者：修诚利 张文慧[1] 赵庆章[1] 何明[1] 包轶文[1] 李康宁[1] 李建良 郭巍 董鹏伟 XIU Chengli;ZHANG Wenhui;ZHAO Qingzhang;HE Ming;BAO Yiwen;LI Kangning;LI Jianliang;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：《同位素》2024年第4期341-346,共6页Journal of Isotopes

摘　　要：在紧凑型加速器质谱系统(AMS)探测低能量离子时,具有相同磁刚度和电刚度的干扰离子会与被测核素一同进入探测器,对探测造成干扰。为解决这个问题,研制一种用于低能量小型AMS的可实现射程检测能力的气体探测器。通过被测核素与干扰离子射程不同,将干扰离子全部吸收在吸收室内,而被测核素可穿过吸收室并进入一个具有正比放大功能的放大室,从而实现被测核素的测定。为了验证气体探测器的性能,使用能量为5.8 MeV的α粒子进行一系列的调试实验。模拟和实验结果表明,吸收室可以有效地吸收不同能量的干扰离子,放大室一路信号的能量分辨率约30%。同时放大室的约化场强在5 V·mm^(−1)·hPa^(−1)时能够将信号放大约7倍,吸收室和放大室两路信号符合后的能量分辨率提高约20%,可为低能量小型AMS开展26Al、129I等核素的测量提供参考。In compact accelerator mass spectrometry(AMS)systems,the detection of low-energy ions is often interfered by interfering ions with the same magnetic rigidity and electric rigidity as the target nuclide.To address this issue,a gas detector with range detection capability was developed for low-energy small-scale AMS.By exploiting the different ranges of the target nuclide and interfering ions,all interfering ions are absorbed in an absorber chamber while the target nuclide can pass through and enter an amplification chamber with proportional amplification functionality,thus facilitating the measurement of the target nuclide.To validate the performance of the gas detector,a series of calibration experiments were conducted using 5.8 MeV alpha particles.Experimental and simulation results demonstrate that the absorber chamber effectively absorbs interfering ions of different energies,and the energy resolution of amplification chamber is around 30%for the one-way signal.At the same time,when the reduced field strength in the amplification chamber is at 5 V·mm^(−1)·hPa^(−1),the signal can be amplified by about 7 times.The energy resolution of the combined signals from the absorber and the amplification chamber is improved to around 20%,laying the foundation for the measurement of nuclides such as 26Al in low-energy small-scale AMS.

关 键 词：加速器质谱 气体电离 干扰离子 吸收室 放大室 

分 类 号：TL811[核科学技术—核技术及应用]