小口径γ能谱测井仪研制
为实现在铀、钍混合型矿床上准确测定铀含量之目的,开发了直径45mm的小口径自然γ能谱测井仪。该γ能谱仪采用闪烁晶体探测器锗酸铋(Bi3Ge4O12jBGO),晶体为030mm×100mm;为减小死时间,从系统角度提出旨在提高数据吞吐率的基于双端口RAM加双CPU结构的仪器设计方案。针对自动稳谱难题,软件上采用基于133Ba自稳参考源的实时四能窗稳谱算法;硬件上基于温度粗调辅以光电倍增管(Photomultiplier Tube,PMT)高压调节的思想,测井仪开机阶段根据测井环境温度设定PMT高压初值,测井过程中根据谱漂移程度实时微调高压,两者结合自动稳谱精度有大幅度提高,结合Pb-Sn组合屏蔽...
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Published in | 核技术 Vol. 38; no. 4; pp. 35 - 40 |
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Main Author | |
Format | Journal Article |
Language | Chinese |
Published |
中国地质大学(北京)地球物理与信息技术学院 北京100083
2015
核工业北京地质研究院中核集团铀资源勘查与评价技术重点实验室 北京100029%中国地质大学(北京)地球物理与信息技术学院 北京100083%核工业北京地质研究院中核集团铀资源勘查与评价技术重点实验室 北京100029 |
Subjects | |
Online Access | Get full text |
ISSN | 0253-3219 |
DOI | 10.11889/j.0253-3219.2015.hjs.38.040403 |
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Summary: | 为实现在铀、钍混合型矿床上准确测定铀含量之目的,开发了直径45mm的小口径自然γ能谱测井仪。该γ能谱仪采用闪烁晶体探测器锗酸铋(Bi3Ge4O12jBGO),晶体为030mm×100mm;为减小死时间,从系统角度提出旨在提高数据吞吐率的基于双端口RAM加双CPU结构的仪器设计方案。针对自动稳谱难题,软件上采用基于133Ba自稳参考源的实时四能窗稳谱算法;硬件上基于温度粗调辅以光电倍增管(Photomultiplier Tube,PMT)高压调节的思想,测井仪开机阶段根据测井环境温度设定PMT高压初值,测井过程中根据谱漂移程度实时微调高压,两者结合自动稳谱精度有大幅度提高,结合Pb-Sn组合屏蔽低能γ射线解决了高含量铀矿体强γ射线对测井仪自动稳谱系统干扰的难题。经放射性标准模型站对谱仪进行多模型标定、死时间修正、水和铁套管吸收系数修正等检测,以及对能谱仪野外实际测试结果对比,结果表明,该小口径自然γ能谱测井仪检查测井异常相对误差不大于10%。 |
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Bibliography: | JIAO Cangwen DENG Ming LU Shili YUAN Ming MA Yanfang1(School of Geophysics and lnformation Technology, China University of Geosciences, Beijing 100083, China) 2(China National Nuclear Corporation, Key Laboratory of Uranium Resources Exploration and Evaluation Technology, Beijing Research Institute of Uranium Geology, Beijing 100029, China) Background: γ spectrometry logging is one method for accurately computing uranium content in uranium-thorium mixed type deposit for slim borehole application. Purpose: The aim is to design slim borehole γ spectrometry logger N451 with 030 mmx 100 mm high detection efficiency Bi4Ge3O12 (BGO) scintillation detector, whose diameter and length are 45 mm and 1 300 mm, respectively. Methods: By applying the configuration of dual-microprocessor plus dual port RAM to improving the data throughput rate, the aim of reducing dead time was achieved. As to auto-stabilization, by means of 4-window algorithm with 133Ba reference source, plus temperature-based coarse set while power on and |
ISSN: | 0253-3219 |
DOI: | 10.11889/j.0253-3219.2015.hjs.38.040403 |