宇宙线活化后锗晶体对探测器的影响研究
发布时间：2018-07-18 10:59
【摘要】：最近的几年探测暗物质已经成为宇宙学和物理学研究中最前沿的课题之一，它必将成为最热门的研究。对暗物质的探测会使我们更近一步的认识宇宙的结构及其形成的过程，由此暗物质的研究将是非常有意义的。在众多被预测的暗物质理论模型中，，弱相互作用重粒子（WIMPs）被认为是重要的候选者。 我国借助于四川锦屏山优异的自然条件，建立了第一个极深地下室——中国锦屏地下实验室（CJPL）。2400米的岩石垂直覆盖深度使得中国的实验室具备了最优越的条件，我国极低本底实验也正式开始了研究。极厚的岩石层以及实验室内部的屏蔽体可以有效地屏蔽宇宙线及其次级粒子的本底影响。但在海平面上宇宙射线激活探测器材料产生的本底，因为存在于实验室的最中心不能被有效地屏蔽，这将成为这类实验的一大隐患，实验材料本身存在的放射性对探测器的影响将是不可忽略的。 高纯锗（HPGe，86%76Ge和14%74Ge）在制造和运输过程中长时间暴露在宇宙线中。在这些过程中，宇宙线活化现象将在HPGe晶体中产生大量的放射性元素。HPGe材料最频繁地在超低放射性本底的实验被使用，那么HPGe被活化产生的影响将是不可忽略的。因此，估算宇宙线活化HPGe晶体产生的放射性对探测器本身的影响是我的工作目标。在本文中根据已知的宇宙线活化HPGe晶体产生的产率为前提，对被活化了的锗晶体在自身内部产生的射线以及在0~12keV的X射线产生的本底水平进行了估计。这些结果可以为实验室去除本底提供参考。
[Abstract]:In recent years, the detection of dark matter has become one of the most popular research topics in cosmology and physics. Detection of dark matter will bring us a closer understanding of the structure of the universe and its formation process, so the study of dark matter will be of great significance. Weak interacting heavy particles (WIMPs) are considered as important candidates in many predicted dark matter theoretical models. With the help of the excellent natural conditions of Jinping Mountain, Sichuan Province, China has established the first extremely deep basement, the China Jinping Underground Laboratory (CJPL). 2400 meters of vertical rock cover depth, which makes the Chinese laboratory have the most favorable conditions. The very low background experiments in China have also officially begun to study. The extremely thick lithosphere and the shielding body inside the laboratory can effectively shield the background effects of cosmic rays and their secondary particles. But the background that cosmic ray activated detector materials are produced at sea level, because the most important centers in the laboratory cannot be effectively shielded, will be a big danger in such experiments. The influence of the radioactivity of the material itself on the detector can not be ignored. High-purity germanium (HPGeN 86vGe and 14tGe) were exposed to cosmic rays for a long time during manufacture and transportation. In these processes, cosmic ray activation will produce a large number of radioactive elements in HPGe crystal. HPGe materials will be used most frequently in ultra-low radioactive background experiments, so the effect of HPGe activation will not be ignored. Therefore, it is my goal to estimate the effect of radioactivity produced by cosmic ray activated HPGe crystal on the detector itself. Based on the known yield of HPGe crystals activated by cosmic rays, the background levels of the internal rays produced by the activated germanium crystals and the background levels of the X-rays generated at 0 ~ 12keV are estimated. These results can provide a reference for laboratory background removal.
【学位授予单位】：辽宁师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P145.9
本文编号：2131698
[Abstract]:In recent years, the detection of dark matter has become one of the most popular research topics in cosmology and physics. Detection of dark matter will bring us a closer understanding of the structure of the universe and its formation process, so the study of dark matter will be of great significance. Weak interacting heavy particles (WIMPs) are considered as important candidates in many predicted dark matter theoretical models. With the help of the excellent natural conditions of Jinping Mountain, Sichuan Province, China has established the first extremely deep basement, the China Jinping Underground Laboratory (CJPL). 2400 meters of vertical rock cover depth, which makes the Chinese laboratory have the most favorable conditions. The very low background experiments in China have also officially begun to study. The extremely thick lithosphere and the shielding body inside the laboratory can effectively shield the background effects of cosmic rays and their secondary particles. But the background that cosmic ray activated detector materials are produced at sea level, because the most important centers in the laboratory cannot be effectively shielded, will be a big danger in such experiments. The influence of the radioactivity of the material itself on the detector can not be ignored. High-purity germanium (HPGeN 86vGe and 14tGe) were exposed to cosmic rays for a long time during manufacture and transportation. In these processes, cosmic ray activation will produce a large number of radioactive elements in HPGe crystal. HPGe materials will be used most frequently in ultra-low radioactive background experiments, so the effect of HPGe activation will not be ignored. Therefore, it is my goal to estimate the effect of radioactivity produced by cosmic ray activated HPGe crystal on the detector itself. Based on the known yield of HPGe crystals activated by cosmic rays, the background levels of the internal rays produced by the activated germanium crystals and the background levels of the X-rays generated at 0 ~ 12keV are estimated. These results can provide a reference for laboratory background removal.
【学位授予单位】：辽宁师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P145.9
【参考文献】
相关期刊论文 前2条
1 郭玉辉,王彦瑜;基于ROOT软件包的数据远程获取系统编程[J];核电子学与探测技术;2005年05期
2 许淑艳;刘保杰;;核技术应用研究中的蒙特卡罗计算问题[J];核技术;2007年07期
本文编号：2131698
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