基于硅光电倍增管的Cs_(2)LiYCl_(6)(CLYC)探测器快中子辐照效应研究

Research on the effects of fast neutron irradiation on silicon photomultiplier tubes and CLYC detectors

实验通过将硅光电倍增管(silicon photomultiplier,SiPM)器件和Cs_(2)LiYCl_(6)(CLYC)闪烁体探测器暴露于14 MeV的快中子场中,最高累积注量达到1.53×10^(11) cm^(-2),分析了中子辐照对SiPM器件参数和CLYC探测器性能的影响。重点研究了不同注量辐照前后,SiPM的增益、暗计数率、暗电流、击穿电压和淬灭电阻等参数,以及CLYC探测器探测性能的变化情况和原因,其中暗计数率最高上升了3个数量级,暗电流最高上升了2个数量级,CLYC探测器的能量分辨率去除本底后下降了1.4%。辐照实验后,在室温条件下对SiPM和CLYC探测器进行退火,研究SiPM器件参数和探测器性能恢复情况。SiPM和CLYC探测器的性能会随着中子注量的增加而逐渐变差。对于SiPM,主要表现为暗计数率和暗电流的提高。对于CLYC探测器,主要表现为能量分辨率的降低。退火过程有助于减轻中子辐照的影响,恢复SiPM和CLYC探测器的部分性能。

In this experiment,the SiPM device and Cs_2LiYCl_6(CLYC) scintillator detector were exposed to a 14 MeV fast neutron field,and the maximum cumulative irradiation fluence reached 1.53×10^(11) cm^(-2).The effects of neutron irradiation on the SiPM device parameters and effects on CLYC detector performance were studied.The focus was on the gain,dark count rate,dark current,breakdown voltage,quenching resistance and other parameters of SiPM before and after irradiation with different fluences,as well as the changes and causes for the detection performance of the CLYC detector.Among them,the dark count rate increased the highest with 3 orders of magnitude,the dark current increased by up to 2 orders of magnitude,and the energy resolution of the CLYC detector decreased by 1.4% after removing the background.After the irradiation experiment,the SiPM and CLYC detectors were annealed at room temperature to study the SiPM device parameters and detector performance recovery.The performance of SiPM and CLYC detectors gradually deteriorates as the neutron fluence increases.For SiPM,the main performance is the increase in dark count rate and dark current.For the CLYC detector,the main manifestation is the reduction of energy resolution.The annealing process helps mitigate the effects of neutron irradiation and restores some performance of SiPM and CLYC detectors.