提高基于Bulk-Micromegas结构的快中子探测器探测效率和位置分辨的方法的研究

项目名称： 提高基于Bulk-Micromegas结构的快中子探测器探测效率和位置分辨的方法的研究

项目编号： No.11275087

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 张小东

作者单位： 兰州大学

项目金额： 87万元

中文摘要： 项目主要研究内容:（1）利用Maxwell、Garfield和Geant4程序模拟并优化三种快中子转换膜（与漂移电极垂直的平行聚丙烯柱子阵列、与漂移电极成45度夹角的平行聚丙烯柱子阵列和多孔聚丙烯转换膜）的快中子转换效率和电子传输效率，给出最大转换效率和电子传输效率所对应的转换膜结构参数和探测器的电压配置；（2）设计并制作基于这些转换膜的两种不同灵敏区面积（21.6×24.0mm2和96.0×96.0mm2）和不同读出电极单元形状的Bulk-Micromegas快中子探测器。研究其位置分辨和探测效率随工作气体的不同气压，内部漂移电场以及不同转换膜的结构参数的变化关系，并对不同样品（铅、聚乙烯、掺硼聚乙烯和子弹）进行快中子成像实验。研制出两种不同灵敏区面积和不同读出电极形状的Bulk-Micromegas快中子探测器，其对于14MeV快中子的位置分辨优于400微米，探测效率1-5%。

中文关键词： 微模式气体探测器；体式微网结构探测器；探测效率；位置分辨；

英文摘要： In this proposal, we will concentrate our research work into two aspects: (1) the simulation of three types of polypropylene-based fast neutron (mainly study 14 MeV neutrons) converters and (2) the R&D (Research and Development) of Bulk-Micromegas fast neutron detector based on these converters. Research work(1): (A) With Maxwell program, simulates the electric potential and field in the detector, especially in the regions of the fast neutron converters. Here, three polypropylene-based converters with different structures are proposed.Two of them consist of the parallel polypropylene pillars which are perpendicular and 45-degree to the drift cathodes respectively. The third type has the micro-channel sturcture. (B) And then passes the electric field to Garfield program. With this program, the transportation efficiency of electrons in these converters will be simulated. By changing the geometrical parameters of the converters and the electric potentials of the detector's electrodes, the designs of convertors and the configurations of electrodes' potential for best transportation efficiency will be obtained. (C) Furthermore, with Geant4 program, builds the model of detectors with different converters, and simulates their detection efficiency for fast neutrons. By repeating and optimizing the processes of (A), (B

英文关键词： Micro-pattern Gaseous Detector；Bulk-Micromegas Detector；Detection Efficiency；Spatial Resolution；