基于LaBr_(3)(Ce)晶体耦合SiPM的位置灵敏探测器的研制与性能校正  

Development and performance calibration of position sensitive detector based on LaBr_(3)(Ce) crystal coupled with SiPM

作　　者：李岩 王川 刘立业[1] 石伯轩 曹勤剑[1] 赵原[1] 夏三强 董佳杰 LI Yan;WANG Chuan;LIU Liye;SHI Boxuan;CAO Qinjian;ZHAO Yuan;XIA Sanqiang;DONG Jiajie(China Institute of Radiation Protection,Taiyuan 030006,China;Nuclear Power Operation Research Institute,Shanghai 200126,China)

机构地区：[1]中国辐射防护研究院,太原030006 [2]核电运行研究(上海)有限公司,上海200126

出　　处：《核技术》2022年第7期51-56,共6页Nuclear Techniques

基　　金：大型公众活动核安保智能辐射探测系统研制(No.HH21050101)资助。

摘　　要：γ相机可用于放射性物质的准确定位,因此在核电站大修以及核退役设施的源项定位等核工业领域具有重要应用价值。针对高能量分辨率、高计数率、小型化γ相机探测器的设计要求,提出了采用8×8根6.4 mm×6.4 mm×20 mm的LaBr_(3)(Ce)晶体阵列通过硅脂耦合8×8的硅光电倍增管(Silicon Photomultiplier Tube,SiPM)阵列的方式构成γ相机的位置灵敏探测器,并根据脉冲信号特征设计了相应的读出电路。通过测试发现,该探测器模块在662 keV的γ射线照射下,64根晶体条的平均能量分辨率为4.96%,最佳的能量分辨率为3.92%,最差为5.91%。后续进行了各个晶体条像素的峰位一致性和灵敏度一致性的测试和校正,取得了较好的效果。测试结果表明:该探测器在能量分辨率、峰位一致性以及灵敏度一致性等性能方面均能够满足预先设定的γ相机成像的设计要求,具备了核工业领域的应用前景。[Background]The detectors of traditional gamma-ray imaging systems cannot meet the radiation detection requirements of positioning for the nuclear industry application.LaBr_(3)(Ce) crystal is a crystal with high light output,very short decay time of luminescence and large density.As a new type of photoelectric conversion device,SiPM has the advantages of small size,anti-magnetic field interference,low power supply voltage,and good time resolution compared with position sensitive photomultiplier tube(PSPMT).[Purpose]This study aims to develop a position sensitive detector based on the LaBr_(3)(Ce) crystal coupled with SiPM to achieve high energy resolution,high count rate and miniaturization.[Methods]An 8×8 LaBr_(3)(Ce) crystal array with pixel size 6.4 mm×6.4 mm×20 mm per crystal bar was employed to couple 8×8 SiPM array with silicone grease to form the position sensitive.Then the corresponding readout circuit was designed according to the characteristics of the pulse signal.Finally,^(137)Cs point sources with different activities were used to test the performance of this detector system and conduct calibration.[Results]Test results show that the average energy resolution of the 64 crystal strips of the detector module is 4.96%,of which the best energy resolution is 3.92%and the worst is 5.91%.Subsequent testing and calibration of the peak position uniformity and sensitivity uniformity of each crystal strip pixel achieve good results.[Conclusions]The position sensitive detector based on the LaBr_(3)(Ce)crystal coupled with SiPM can meet the design requirements of gamma camera imaging in the nuclear industry in terms of energy resolution,peak position uniformity and sensitivity uniformity.

关 键 词：LaBr_(3)(Ce)晶体 位置灵敏探测器 γ 相机 灵敏度一致性校正 峰位一致性校正 

分 类 号：TL812.1[核科学技术—核技术及应用]