为了快速定位并寻回丢失的放射源,设计了一种由NaI、CsI、锗酸铋(Bi4Ge3O12,BGO)三种晶体与铅耦合组成的γ射线方向探测器,并采用基于蒙特卡罗方法的通用软件包MCNP(Monte Carlo N Particle Transport Code)研究了铅晶比例、射线能量、剂量率等因素对探测器角度分辨率的影响。结果表明,对于137Cs源,在空气吸收剂量率≥0.331μGy·h~(-1)处,定位角度偏差≤0.99°;对于60Co源,在空气吸收剂量率0.586μGy·h~(-1)处,测量的平均角度偏差为0.46°;对于水平距离7 m、高度4 m的3.7×107Bq 137Cs源,相对定位偏差约为5%。 In order to rapidly locate and recover the lost radioactive sources, a γ-ray detector with coupling of Pb, NaI, CsI and bismuth germanate (Bi4Ge3O12, BGO) was designed and a Monte Carlo method based The generic software package MCNP (Monte Carlo N Particle Transport Code) studies the influence of lead ratio, radiation energy, dose rate and other factors on the angle resolution of the detector. The results showed that for the 137Cs source, the angular deviation of orientation was ≤0.99 ° at the air dose rate of ≥0.331μGy · h ~ (-1) and at the air dose rate of 0.586μGy · h ~ (-1) for the 60Co source , And the average angular deviation is 0.46 °. For a 3.7 × 107Bq 137Cs source with a horizontal distance of 7 m and a height of 4 m, the relative positioning deviation is about 5%.