二维多丝室探测器读出方法的优化

摘要

A two-dimensional multi-wire proportional chamber detector based on 3He gas is developed for meeting the multifunctional reflection spectrum detection requirements of China Spallation Neutron Source (CSNS).Based on the previous researches in our laboratory,three different wire structures are studied for optimizing the wire readout structure of the two-dimensional multi-wire proportional chamber detector,and the performances of the detectors are measured by two readout methods:the center of gravity readout method and the digital readout method in this paper.The selected method could satisfy the requirement of multifunctional reflection spectrum instrument.Finally,the results indicate that the position resolution and the imaging capability obtained by using the center of gravity readout method should be better than by using the digital readout method.The position resolution could reach to about 160 μm by using the center of gravity readout method.While the position resolution of the detector could be obtained to be about 400 μm by using the digital readout method.Re-designed and compared with each other are the three different wire structures:1.5 mm of the anode wire pitch and 4 mm of the readout strip pitch with the center of gravity readout method,1.5 mm of the anode wire pitch and 2 mm of the readout strip pitch with the digital readout method.Both of the optimized designs of the wire structure could meet the requirement of the position resolution for the reflection spectrum device.%中国散裂中子源将建设一台基于3He气体的二维多丝室,作为多功能反射谱仪束线的中子探测器.基于已有的研究,为优化选择二维多丝室探测器的丝结构,本文研究了三种不同的丝结构,并采用重心读出方法和数字读出方法进行了探测器的性能测量,得到了满足多功能反射谱仪探测器需求的读出方法.实验结果表明:对同种丝结构的二维多丝室探测器,重心读出方法的位置分辨和成像性能都好于数字读出方法;基于重心法读出的多丝室探测器位置分辨率可以达到约160 μm,基于数字读出方法的多丝室探测器位置分辨率可以达到约400 μm.优化设计的丝结构为:基于重心读出法的阳极丝间距1.5 mm、读出通道间距4 mm,基于数字读出法的阳极丝间距1.5 mm、读出通道间距2 mm.优化设计的丝结构均能满足谱仪的位置分辨要求.