核测井NaI、BGO和LaBr_3探测器响应的M-C模拟  

M-C simulation ofγ-ray energy responses to NaI,BGO and LaBr_3 crystals as scintillators in nuclear logging

作　　者：吴文圣[1] 何景枝[1] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249

出　　处：《核技术》2011年第12期909-915,共7页Nuclear Techniques

基　　金：国家自然科学基金(41074101)资助

摘　　要：应用Monte Carlo数值模拟,计算了NaI、BGO和LaBr_3晶体探测器对0.662 MeV和6.13 MeVγ射线的能量沉积谱,对比了不同能量γ射线的能量沉积谱和响应函数,分析了晶体尺寸对能量沉积谱的影响。计算结果表明,在低能段,晶体长度和直径对BGO晶体探测效率影响均大于NaI和LaBr_3晶体;晶体直径对探测效率的影响大于晶体长度。在γ射线高能段,晶体长度和直径对三种探测器探测效率的影响较小;晶体直径对探测效率的影响小于晶体长度。BGO晶体探测器在γ射线低能段的全能峰和反散射峰强度及在γ射线高能段的光电峰和第一逃逸峰强度均最大,探测效率最高。Some factors should be considered in selecting a crystal scintillator type in y logging and n-γ logging. In this paper, spectra of 0.662 and 6.13 MeV γ-rays using NaI, BGO and LaBr3 scintillators are simulated with an M-C code, so as to compare their y-ray energy deposition spectra and detector responses, and analyze the detector parameter effects on the spectrum. The results show that in the low energy region, the detector length and diameter have greater effect on detection efficiency of BGO than that of NaI and LaBr3, and the diameter effect on the detection efficiency is greater than that of the length. In high energy region, the detector size effect is small, and the crystal diameter affects less than the crystal length. Among the three types of crystal scintillators, BGO has the greatest detection efficiency, and the highest intensity in terms of the full energy peak and backscattering peak in low energy region, and photon peaks and the first-escaping peak in high energy region.

关 键 词：核测井 闪烁晶体 能量沉积谱 探测器响应 蒙特卡罗模拟 

分 类 号：P631.8[天文地球—地质矿产勘探]