新型溴化镧闪烁晶体探测器研制

摘要

With optimized material and packaged technology,a new LaBr3 scintillation crystal detector for γrays is presented.It consists mainly of one piece of Φ1.5" × 1.5" LaBr3:5％ CeCl3 scintillation crystal and a R6231-100 PMT,which are coupled with each other by organic silicone resin,then sealed integrally in Al-alloy housing.The scintillation detector has an excellent energy resolution (FWHM) of 2.8％ at 662 keV,0.96％ non-proportionality of energy response between 500-1400 keV,0.2％ change of? pulse height with different directions,and-0.65％/℃ change of? pulse height with temperature between-30℃ and +40℃.It has an internal activity of up to 0.99 cps/cc which result from 227Ac and its daughters and maybe further reduced soon,besides that of about 0.077 cps/ccfrom 138La isotope.%采用优选的封装材料及优化的工艺,将Φ1.5"×1.5"的LBC闪烁晶体与R6231-100光电倍增管直接耦合,并整体封装在铝合金外壳中,制成新型溴化镧闪烁晶体探测器.该探测器的能量分辨率为2.8％ (137Cs),在500 keV～1400 keV范围内能量响应的非线性为0.96％,脉冲幅度随探头方向的变化量为0.2％,在-30至+40c℃范围内脉冲幅度输出的温度系数为-0.65％/℃.探测器除了来自于138La的0.077cm-3.s-1本底辐射外,还有来源于227 Ac及其子体的0.99cc-1.s-1本底辐射.