【作者】 胡继峰；

【导师】 姚泽恩； 张国光；

【作者基本信息】 兰州大学 ， 粒子物理与原子核物理， 2010， 硕士

【摘要】 本文首先给出掺钆(Gd)高阻性板室(RPC)热中子探测器基本原理,特别是Gd与热中子的反应机理。其次,根据探测器结构建立了模拟模型,利用MCNP和Garfield程序模拟了粒子与RPC热中子探测器的作用过程,计算了换体Gd203的合适厚度和RPC探测器对中子、γ的灵敏度,给出了热中子和1.25MeV能量γ与探测器作用产生的电子能谱。利用模拟数据研究了RPC热中子探测器的探测效率和时间分辨随电场、混合气体比例的变化规律,得到了最佳的电场强度和混合工作气体比例。根据模拟结果设计和研制了掺钆RPC热中子探测器,最后,对掺钆高阻性板室(RPC)热中子探测器性能进行了测试。用γ射线吸收法对探测器膜的厚度进行了测量；对探测器的示波器信号进行了研究；使用探测器对常见的Na-22和Cs-137γ放射源进行了测试,得到了信号幅度谱,初步研究了能量分辨；还利用D-D中子管经过慢化提供的热中子测试了探测器的探测效率,找到提高探测效率最佳条件。更多还原

【Abstract】 Firstly, the reaction mechanism of the thermal neutron with Gd and the basic principles of the Gd-coated thermal neutron resistive plate chambers detector was investigated in this paper. Secondly, the sensitivities of y-ray and the neutron in the Gd-coated thermal neutron resistive plate chambers detector were simulated using MCNP code and Garfield code. The electron energy spectra that the detector interacts with the thermal neutron and 1.25 MeVγ-ray were also presented. The relationship of the time resolution and the detection efficiency vs the electric field and the proportion of the mixture gas were calculated. Based on the simulating data, the optimal electric field and the proportion of the mixture are presented. A new method using the characteristicγ-ray absorption spectroscopy was developed to measure the thickness of the Gd-coated. At last, the Gd-coated thermal neutron resistive plate chambers detector was tested at theγray source of Na-22 and Cs-137. The the signal amplitude spectrum and energy resolution of theγ-ray were presented. A D-D neutron and a polythene moderator were used to get a thermal neutron beam. Using this thermal neutron beam, thermal neutron efficiency of the detector was also tested to find the better conditions.更多还原