基于GEM探测器的阻性阳极二维插值读出方法研究

鉴于北京同步辐射装置对二维位置灵敏探测器的实际需求，本项目针对微结构气体探测器传统的读出条读出方法，提高位置分辨需要匹配大量读出电子学通道而造成建造成本剧增的问题，研究基于GEM探测器的阻性阳极插值读出方法及其二维位置重建算法。研制较大面积Pad（cm量级）的阻性阳极读出结构，分析不同工作气体、不同电场下，阻性读出Pad上电子束团扩散、收集过程，研究探测器的位置分辨、计数能力等性能与阻性读出结构参数之间的关系。优化设计阻性结构，提高探测器性能，研制可用于同步辐射10keV能量范围内的阻性阳极插值读出GEM探测器。该读出方法的实现在保证探测器满足同步辐射测量高计数率（>100kHz）和高位置分辨率（<200μm）的条件下，能够有效减少读出电子学通道，降低探测器的研制成本，提高GEM探测器在高计数率下的工作稳定性，推动GEM探测器在同步辐射上的应用。

For the traditional strip readout of micro-pattern gaseous detector, a large number electronic readout channels are required to improve the position resolution, which leads to an enormous increase in the cost of detector construction. So the two-dimensional interpolating readout method with resistive anode based on gas electron multiplier (GEM) and its corresponding two dimensional position reconstruction method will be studied in this project for the demand of two dimensional position sensitive detectors to Beijing synchrotron radiation facility (BSRF). We will develop a resistive anode readout structure with large area pad, whose dimension is as large as square cm. Measure and analyze the distribution and diffusion of the electron bunch in the resistive readout pads, in different conditions of working gas, electric field. Study the relationship between the position resolution and count rate capability of the detector and the parameters of the resistive readout structure. Optimize the design of the resistive structure to improve the performance of the detector. Finally develop a GEM prototype with the two-dimensional interpolating resistive readout structure, which should be used for the synchrotron radiation measurement in the energy range of 10keV. The realization of this two dimensional interpolating readout method with resistive anode for GEM detector will not only meet the BSRF application demanding high count rate capability (>100kHz) and high position resolution (<200μm), but also reduce the number of readout electronics efficiently, and save the cost of the detector construction. In addition, the resistive anode readout structure can relieve the discharge of GEM detector, and make the detector robust and stable working at the high count rate, which will promote the application of the two dimensional position sensitive GEM detector in BSRF.