用于在线测量反应堆内热中子相对通量密度分布的闪烁体光纤探测器研究  

Study on Scintillator Fiber Detector for Online Measurement of Thermal Neutron Relative Flux Density Distribution in Reactor

作　　者：李严严[1,2] 张雪荧[1] 张艳斌[1] 刘锋[3] 马飞[1] 万波[1,2] 葛红林[1] 张宏斌[1] 陈亮[1] 

机构地区：[1]中国科学院近代物理研究所,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]中国原子能科学研究院,北京102413

出　　处：《原子能科学技术》2017年第7期1290-1295,共6页Atomic Energy Science and Technology

基　　金：中国科学院战略性先导科技专项资助项目(XDA03030300);国家自然科学基金重大研究计划集成项目资助(91426301)

摘　　要：闪烁体光纤探测器采用双探头甄别中子信号,利用252 Cf裂变源对探测器系统进行了测试,并与3 He计数管的计数进行了对比。在启明星1#上进行了热中子相对通量密度分布的测量,结合Geant4得到的不同能量段的中子转化率及MCNPX模拟得到的反应堆中子能谱,对探测器进行了相对效率刻度,测试结果与固体核径迹探测器测得的裂变率分布进行了对比。测量结果表明,闪烁体光纤探测器对于252 Cf中子源的响应基本符合点源的衰减趋势,与3 He计数管的测量结果符合较好。在启明星1#热区测得的热中子相对通量密度分布与固体核径迹探测器测量到的结果一致,快区测得的热中子相对通量密度分布与3 He计数管的测量结果及MCNPX的模拟结果符合较好。测量结果为闪烁体光纤探测器的研究提供了较好的实验依据。The scintillator fiber detector used two probes to identify the neutron signal.The detector system was tested by ^252 Cf fission source and was compared with the ^3 He counter.Meanwhile,the detector was used in Venus 1#assembly to measure the thermal neutron relative flux density distribution.The relative efficiency of the detector was calibrated with the neutron conversion rate from Geant4 code and neutron spectrum from MCNPX code.The results were compared with the fission rate measured by solidstate nuclear track detector.The measurement results show that the response of thescintillator fiber detector to the ^252 Cf neutron source agrees well with the attenuation of the point source,which is in good agreement with the counting rate of ^3 He counter.The relative distribution of the thermal neutron relative flux density measured at the Venus1#thermal zone is consistent with fission rate distribution by the solid-state nuclear track detector.The same result of fast region is in line with the counting rate distribution measured by ^3 He counter and simulated by MCNPX code.The results provide important experimental data for the development of the detector.

关 键 词：闪烁体光纤探测器 中子通量密度 在线测量 GEANT4 MCNPX 

分 类 号：TL812[核科学技术—核技术及应用]