闪烁光纤阵列探测器最小可探测活度浓度仿真计算  

Simulation analysis of minimum detectable activity concentration of scintillating optical fiber array detector

作　　者：吕汶辉 杨永新[1] 衣宏昌[2] 曾志[2] 刘翠红 陈迎锋[1] 丁雄 商学利[1] LYU Wenhui;YANG Yongxin;YI Hongchang;ZENG Zhi;LIU Cuihong;CHEN Yingfeng;DING Xiong;SHANG Xueli(Unit 92609 of PLA,Beijing 100077,China;Department of Engineering Physics,Tsinghua University,Beijing 100084,China)

机构地区：[1]中国人民解放军92609部队,北京100077 [2]清华大学工程物理系,北京100084

出　　处：《哈尔滨工程大学学报》2022年第11期1636-1641,共6页Journal of Harbin Engineering University

摘　　要：为评估闪烁光纤阵列探测系统的性能,本文采用理论分析、模拟仿真等方法对系统的最小可探测活度浓度进行仿真分析。最小可探测活度浓度取决于系统的本底计数率和探测效率,首先对系统的探测效率进行了MC模拟,包括弯曲损耗和长度损耗对荧光传输的影响,获取了探测系统对不同能量β粒子的探测效率;其次对探测系统的本底计数率进行了仿真分析,包括空间宇宙射线、屏蔽材料产生的辐射及电子学系统噪声等。经计算,长度为1 m的2025根闪烁光纤阵列探测系统的本底计数率约为^(60) s^(-1),对于^(40)K的β粒子的探测效率为1.86 s^(-1)/(Bq/L)。该探测系统6 min内探测系统最小可探测活度浓度可达到1.0 Bq/L,30 min内可达到0.457 Bq/L,可用于水中低水平放射性测量。The minimum detectable activity concentration of the system is simulated and analyzed via theoretical analysis and simulation to evaluate the performance of scintillating fiber array detection systems.The minimum de-tectable activity concentration depends on the background count rate and detection efficiency of the system.First,the detection efficiency of the system,including the effects of bending and length losses on fluorescence transmis-sion,is simulated by Monte Carlo to obtain the detection efficiency of detection systems for different energies ofβparticles.Second,the background counting rate of the detection system,including space cosmic rays,radiation generated by shielding materials,and electronic system noise,is simulated and analyzed.Through calculation,the background counting rate of the 2025 scintillating fiber array detection system with a length of 1 m is approximately ^(60) s^(-1),and the detection efficiency ofβparticles for ^(40)Kβis 1.86 s^(-1)/(Bq/L).The minimum detectable activity concentration of the detection system can reach 1.0 and 0.457 Bq/L within 6 and 30 min,respectively,which can be used for low-level radioactivity measurement in water.

关 键 词：闪烁光纤 蒙特卡罗模拟 在线测量 最小可探测活度浓度 探测效率 荧光 

分 类 号：TL81[核科学技术—核技术及应用]