Prototype Of Neutron Senensitive Mwpc Detector With Delay-line Readout

Due to its unique characteristics,neutron scattering technology has become an ideal detection technique for studying the internal structure and dynamics of materials.The technique is widely used in many disciplines such as condensed matter physics,chemistry,life sciences,materials science and so on.The China Spallation Neutron Source(CSNS),which was built in 2008.It is in urgent need of a Multi-wire Proportional Chamber(MWPC)detector with a high performance index.In recent years,the price of 3He gas has led to the lack of such detectors.We have developed a MWPC detector instead of 3He gas.In the development process,in order to solve the problem of electronic circuit complexity brought about by the signal readout method of the detector and to obtain a good neutron position resolution performance index more conveniently,the delay block is used to read out the signal of the MWPC detector.The signal readout method based on the delay block converts the position information containing the position of neutrons into the time difference between the two ends of the delay block,then calculates the position information of the neutrons incident on the detector by measuring the time difference.For the two ends of the delay block,only two electronic circuits need to be connected to the MWPC detector,thereby greatly reducing the complexity of reading out the electronic circuit and analyzing the performance index more conveniently.In this paper,MWPC detectors were firstly developed through theoretical calculations and simulation packages.In this process,key technologies such as the application of 10 B neutron conversion layer,detector structure design,working gas selection,string tension and spacing were clarified.The preliminary performance of the MWPC detector verify that the detector can work normally and stably.Then the design of the delay block,the delay time difference between the two ends of the delay block and the positional relationship are studied.Finally,the delay block is applied to the MWPC detector,the alpha source and the neutron source are used to perform joint performance test experiments respectively.By measuring the delay time difference between the two ends of the delay block,the position coordinates of the incident charged particles generated in the MWPC detector are obtained and the corresponding position resolution results are analyzed.The position measurement results from the alpha source show that the delay block can be used for the signal readout of the MWPC detector.The position resolution is better than 2 mm and the performance obtained by the MWPC detector based on the 3He gas is better.The test results from the neutron source shows that the entire joint test system can be used for detecting the neutrons.The combination of the MWPC detector coating with the delay block readout method and the good position resolution performance of the coated MWPC detector can be applied to neutron detection.This is the development of an innovative MWPC detector combined with readout of delay blocks,and is also the first application of neutron detection,providing experimental reference for the development of MWPC detectors and the skilled use of delayed block readout methods.Subsequent experiments with other detectors and electronics provide valuable experience.It is of great significance to promote the matching of new neutron detectors with electronics and the study of new signal readout methods.