砂岩型铀矿土壤热释光特性及测量流程优化  

Thermoluminescence Characteristics of Sandstone-type Uranium Deposit Soil and Optimization of Measurement Process

作　　者：张欣熠 王猛 谷懿[1,2] 王勇[3] 葛良全[1,2] 张庆贤[1,2] 李潇潇 ZHANG Xinyi;WANG Meng;GU Yi;WANG Yong;GE Liangquan;ZHANG Qingxian;LI Xiaoxiao(Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province(Chengdu University of Technology),Chengdu 610059,China;College of Nuclear Technology and Automation Engineering,Chengdu University of Technology,Chengdu 610059,China;Beijing Research Institute of Uranium Geology,Beijing 100029,China)

机构地区：[1]成都理工大学四川省地学核技术重点实验室,四川成都610059 [2]成都理工大学核技术与自动化工程学院,四川成都610059 [3]核工业北京地质研究院,北京100029

出　　处：《原子能科学技术》2024年第2期471-480,共10页Atomic Energy Science and Technology

基　　金：中国核工业地质局铀矿地质项目(202205-6);国家自然科学基金(42127807);四川省自然科学基金(2023NSFSC0008);四川省青年科技创新团队项目(2021JDTD0018)。

摘　　要：砂岩型铀矿因其矿体埋深大、辐射信息被掩盖,传统放射性物探技术难以满足其勘查需求。本文基于天然土壤热释光测量技术,对砂岩型铀矿表层沉积岩样品的热释光特性进行了深入研究,明确了稳定热释光信号主要来源于长石与石英矿物成分。通过甄选稳定的热释光信号,并基于200、237、263、325、375℃下稳定的热释光信号建立了适用于砂岩型铀矿勘查的优化测量流程。针对长石和石英混合矿物成分,测量流程选取的热释光信号在0~600 Gy辐照剂量范围内具有较好的剂量响应特性,且等效剂量测量值相对误差小于7%,兼顾了测量效率与准确性,可为天然土壤热释光法应用于砂岩型铀矿勘探提供技术参考。As a technique in the measurement of accumulated radon for uranium resource exploration,the natural soil thermoluminescence method is widely applied in the exploration of sandstone-type,granite-type,and volcanic rock-type uranium deposits,and achieves good results in Inner Mongolia,Jiangxi,Hunan,and other places,and delineates the spatial distribution of concealed uranium deposits in geological bodies.However,the natural soil thermoluminescence method often uses the thermoluminescence signal corresponding to the entire soil for soil thermoluminescence measurement,which may result in the inclusion of unstable luminescence signals with severe abnormal attenuation in the thermoluminescence signal of the entire soil,thereby reducing the resolution of the natural soil thermoluminescence method for weak abnormal information of deep uranium deposits.In this study,thermoluminescence analysis was carried out on soil samples from sandstone-type uranium deposits in the Qinghai Qaidam Basin(QH sample)and the Ordos Basin(TL sample).The distribution of luminescence signals under different pre-processing stages was obtained,and the luminescence signals of the main mineral components(Na 2CO_(3),MgCO_(3),orthoclase,NaHCO_(3),albite,CaCO_(3),quartz)in the soil samples were reconstructed using the computerized glow curve deconvolution method,in order to further clarify the accurate sources of the changes in the TL signals under different pre-processing stages.In order to analyze the sources of unstable TL signals in soil samples,four different storage time(0,20,40,and 60 h)was set after irradiation,and the next measurement step was done after the storage time was reached.It is found that the temperature range where stable TL signals existed is between 200-400℃and the TL decay curve is basically stable at a time interval of 60 h.By comparing the TL decay curves measured after preheating and infrared excitation with the TL decay curve measured under the 60 h time interval,it is found that the luminescence signals obtained after pre

关 键 词：砂岩型铀矿 释光特性 稳定释光信号 释光测量流程 

分 类 号：TL816.7[核科学技术—核技术及应用]