基于γ谱形差异的定量分析对含铀矿体直接铀定量方法  

A Method for Determining Uranium Content Directly for Uranium-bearing Ore-body Based on Quantitative Analysis for Spectral Shape Difference

作　　者：吴永鹏[1,2,3] 汤彬[2,3] 程建平[1] 王哲[3] 梁永顺[3] 

机构地区：[1]清华大学工程物理系,北京100084 [2]东华理工大学,南昌330013 [3]核技术应用教育部工程研究中心(东华理工大学),南昌330013

出　　处：《核电子学与探测技术》2012年第2期150-155,共6页Nuclear Electronics & Detection Technology

基　　金：国家自然科学基金项目"铀矿能谱型核测井全谱解析的核素含量定量解释方法研究"(41074078)

摘　　要：对含铀矿体,γ能谱法直接铀定量可采用HPGe谱仪测量234mPa之1.001 MeV弱特征峰来实现。然而,闪烁体谱仪不能获得含铀矿体精细γ谱,其仪器谱也反映不出与铀含量直接相关的这一特征峰。因此,需要研究一种有效提取该弱信息以直接获得铀含量的方法。采用CR-320型便携式NaI(Tl)谱仪对系列含铀硬岩体模型进行测量,定量分析各矿体模型中心点位置γ仪器谱中该特征能量窗谱形的差异,结合线性回归相对分析法进行直接铀定量。分别对234mPa之1.001 MeV和发射强度更低的0.743 MeV特征能量,都获得了良好效果,满足铀矿勘探对硬岩型铀矿含铀500 ppm以上误差不超过10.0%的要求,对主要核素定量的最大误差为9.9%。Uranium content can be determined directly based on 234mpa, 1. 001 MeV, weak characteristic energy peak measured by HPGe detector spectrometer for uranium - bearing ore - body. However, scintillation spectrometer cant measure the fine structure of gamma spectrum from uranium - bearing ore - body, and the spectrum measured dont show the characteristic peaks which are directly related to uranium. Therefore, a technique which can be used to extract the＇weak information effectively to determine uranium content directly is needed to study. The present work measures a series of hard rock radionuclide - bearing ore - body using 320CR model portable NaI （Tl） spectrometer, analyzes quantitatively shape difference within the energy windows for the spectra which are collected at centre point of these ore - body model respectively. It determines uranium contents directly using linear regression relative analysis based on 234mPa, 1. 001 MeV and 0.743 MeV whose photons emission intensity is lower, and gets good results, respectively. The results meet the requirement that the relative error of uranium content over 500 ppm is less than 10.0% for hard rock ore - body, and the maximal error of main radionuclide content is 9.9%.

关 键 词：含铀矿体 NaI(Tl)γ谱仪 直接铀定量 谱形差异定量分析 

分 类 号：TL81[核科学技术—核技术及应用]