The Research Of Optimized Structure And Performance For 2D Multi-Wire Chamber

According to the demand of China Spallation Neutron Source(CSNS), The multi-functional reflection spectrometer with an area of 200mmx200mm and two-dimensional position resolution of 2mm was developed. Compared with other types of neutron detector, Two dimensional multi-wire chamber gas detector based on 3He has significant advantages in the position resolution and detector efficiency performance. Two-dimensional multi-wire chamber gas detector consists of gold-plated tungsten wires and metal strips. The induced signal is produced by two layer perpendicular of several adjacent readout wires and readout strips, also produced by several adjacent anode wires when X-ray incident on anode wires with high voltage. By measuring induced charge of the upper and lower readout layers, obtaining the two-dimensional position of the incident particle. By measuring induced charge of the anode wires layer, obtaining the energy of the incident particle. This paper focuses on the main factors of affecting the detector performance, including the design of the detector structure, the readout methods, wire tension and working gas. In order to design the two dimensional multi-wire chamber gas detector to meet the requirements of the multi-functional reflection spectrometer. The experiment designed three kinds of different structure of two dimensional multi-wire chamber gas detectors with the size of 1:1. By 55Fe X-ray, the performance of detector is measured with readout methods of center of gravity and digital. The experimental results show that:The energy resolution of three detectors is about 25%. With the center of gravity readout method, the position resolution of paralleling to the anode wire direction of three detectors is better than 300μm, and the position resolution of perpendicular to the anode wire direction of three detectors is equal to the anode wire spacing. The position resolution of three detectors with digital readout method is equal to the corresponding spacing of readout channels. Three different structures of two dimensional multi-wire chambers have good imaging performance with the center of gravity readout method and meet the requirements of multi-functional neutron reflection spectrometer. With the digital readout method, the detector with structure of 1.5mm anode spacing,2 readout wires as a channel has better imaging performance and meets the requirements of multi-functional neutron reflection spectrometer.