面向核退役场景的阵列式康普顿相机成像系统研制  

Development of Imaging System of Array Compton Camera for Nuclear Decommissioning Scenarios

作　　者：刘鑫 冯鹏[1] 姚志阳 张颂 钱易坤 刘易鑫[2] 吴健[2] 袁永刚[2] 瞿金辉 白彦君 Liu Xin;Feng Peng;Yao Zhiyang;Zhang Song;Qian Yikun;Liu Yixin;Wu Jian;Yuan Yonggang;Qu Jinhui;Bai Yanjun(Key Laboratory of OptoElectronic Technology&Systems,Ministry of Education,Chongqing University,Chongqing 400044,China;Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621900,Sichuan,China;Department of Engineering Physics,Tsinghua University,Beijing 100084,China)

机构地区：[1]重庆大学光电技术及系统教育部重点实验室,重庆400044 [2]中国工程物理研究院核物理与化学研究所,四川绵阳621900 [3]清华大学工程物理系,北京100084

出　　处：《光学学报》2022年第24期123-131,共9页Acta Optica Sinica

基　　金：核退役治理科研项目(科工二司【2018】1521号);重庆市研究生科研创新项目(CYB21059,CYS22111);重庆市科委基础研究与前沿探索专项(cstc2020jcyj-msxmX0899)。

摘　　要：基于23×23阵列GAGG(Ce)探测器以及行/列读出电路设计并研制了适用于核退役场景的康普顿相机系统,探测器由阵列式掺铈钆铝镓石榴石[GAGG(Ce)]耦合硅光电倍增管(Si-PM)而成;开发了基于GPU加速的SOE(subsetdriven origin ensemble iteration)算法,用于加速重建过程。完成研制后,评估了探测器及系统性能:探测器性能方面,所研制相机的能量分辨率为6%±0.6%@662 keV(半峰全宽),位置分辨率为2.2 mm,探测器能量线性度良好(线性拟合优度R2=0.991);成像性能方面,对于活度为1.11×10^(7)Bq的^(137)Cs点源,将其放置在成像系统正前方3.4 m处的初步成像时间仅需20 s,成像系统角分辨率为7°@JND(just noticeable difference)。最后针对应用场景进行了模拟,结果表明:本文研制的康普顿相机可在π视场范围内同时对多个放射源进行成像定位,可用于核退役放射性测量过程,减少作业人员受照剂量。This paper designs and develops a Compton camera system suitable for nuclear decommissioning scenarios with a detector containing a 23×23 array of cerium-doped gadolinium aluminum gallium garnet[GAGG(Ce)]and row/column readout circuits.The detector is composed of an array of GAGG(Ce)coupled with silicon photomultipliers(Si-PMs).A subset-driven origin ensemble iteration(SOE)algorithm based on graphics processing unit(GPU)acceleration is developed to accelerate the reconstruction process.After development is completed,the detector performance and system performance are evaluated.In terms of detector performance,the energy resolution and position resolution of the developed camera are 6%±0.6%at 662 keV(full width at half maximum)and 2.2 mm,respectively.The detector also exhibits favorable energy linearity(goodness of linear fit R^(2)=0.991).Regarding imaging performance,the initial imaging of a ^(137)Cs point source with an activity of 1.11×10^(7) Bq takes only 20 s when it is placed at 3.4 m in front of the imaging system.The angular resolution of the imaging system is 7°@JND(just noticeable difference).Finally,a simulation is carried out in the application scenario.The results show that the Compton camera developed in this paper can simultaneously image and position multiple radioactive sources within theπfield of view.It can be used in radioactivity measurement in nuclear decommissioning to reduce the exposure dose of operators.

关 键 词：成像系统 核退役 放射性测量 康普顿相机 掺铈钆铝镓石榴石 

分 类 号：TL812.1[核科学技术—核技术及应用]