基于液闪EJ301研制的中子探测器的性能测试  

Evaluation of self-developed neutron detector based on EJ301 liquid scintillator

作　　者：张少东 金宝亮 张小东 ZHANG Shaodong;JIN Baoliang;ZHANG Xiaodong(North China Electric Power University,Beijing 102206,China;Shenzhen Key Laboratory of Nuclear and Radiation Safety,Institute for Advanced Study in Nuclear Energy&Safety,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China)

机构地区：[1]华北电力大学,北京102206 [2]深圳市核与辐射安全重点实验室中国核能与安全高等研究院深圳大学物理与光电工程学院,深圳518060

出　　处：《核技术》2024年第8期59-66,共8页Nuclear Techniques

摘　　要：随着核能和核技术的飞速发展,特种殊核材料的应用越来越广泛,为了提高核材料监测能力,基于液闪探测器的核材料无损检测技术得到了广泛的研究。基于液体闪烁体EJ301,自主设计研制了灵敏体积为直径7.62 cm、厚度5.08 cm的液体闪烁体探测器,并对该液体闪烁体探测器的中子/伽马(n/γ)甄别性能进行了测试。首先,使用22Na和60Co γ源对探测器进行能量刻度;然后,使用252Cf中子源对探测器的n/γ甄别性能进行测试,并基于电荷比较法计算出不同能量阈值下的FOM(Figure of Merit)值,并与Eljen公司的EJ301和Saint-Gobain的BC501A液体闪烁体探测器就n/γ甄别性能进行了比较;最后,使用飞行时间法对液体闪烁体探测器的绝对n/γ甄别性能进行了评价。测试结果表明:自主研发的液体闪烁体探测器的n/γ甄别性能略优于Eljen公司的EJ301和Saint-Gobain的BC501A液体闪烁体探测器;在能量阈值为150 keV时,利用飞行时间法作为n/γ甄别的绝对标准,测试得到自主研发的探测器在使用电荷比较法时的伽马误甄率别仅为万分之一。[Background]In recent years,the rapid advancement of nuclear energy and technology has led to the expanded utilization of special nuclear materials in more applications.In the pursuit of enhancing nuclear materials monitoring capability,extensive research has been dedicated to fast neutron multiplicity measurement systems based on liquid scintillation detector.However,these detectors are predominantly manufactured by foreign companies,such as Eljen and Saint-Gobain.[Purpose]This study aims to evaluate the performance of a self-developed neutron detector based on EJ301 liquid scintillator.[Methods]First of all,a 7.62 cm-diameter,5.08 cm-thick liquid scintillator was applied to the development of neutron detector named EJ301-Z liquid scintillator detector,and 22Na and 60Co gamma sources were employed to calibrate this detector for establishing the relationship between incident particle energy and deposited energy.Subsequent tests on the neutron-gamma discrimination performance of the detector were conducted with a 252Cf neutron source,and figure-of-merit(FOM)values at different energy thresholds were calculated based on the charge comparison method.Then,comparison of the neutron-gamma discrimination performance of the detector with Eljen's EJ301 and Saint-Gobain's BC501A liquid scintillation detectors wereconducted to evaluate the detector's performance relative to these commercially available models. Finally, the resultsobtained using the time-of-flight method were used to validate the results of the charge comparison method,providing an assessment of the absolute neutron-gamma discrimination performance of the liquid scintillator detector.[Results] The experimental results show that, the EJ301-Z detect outperforms both Eljen EJ301 and Saint-GobainBC501A detectors in terms of neutron-gamma discrimination, with an energy threshold of 150 keV, the rate ofgamma mis-discrimination (RGMD) of EJ301-Z detector with the charge integration method is as low as 0.1‰.[Conclusions] The developed detector of this study demons

关 键 词：液体闪烁体探测器 能量刻度 中子/伽马甄别 电荷比较法 飞行时间法 

分 类 号：TL81[核科学技术—核技术及应用]