Design Of Electronics Readout System For Multilayer Array Of CZT Detectors

Humans have been further discovered the Space with the advanced development of social progress and technology.In recent years,new technologies,methods and instruments have been applied in the detection of the space radiation environment.Chinese development of space detection is later than that of traditional development countries,but we have made great progress,especially in the field of manned space flight project,Beidou navigation engineering,etc.This study develops a composite probe spectrometer to measure such parameters as the identification,energy spectrum,flux and angle,for the real-time on-orbit monitoring of the space radiation environment.Relying on the subject goal,this study mainly completes the multi-channel readout electronics system of a new high-granularity calorimeter based on CZT(CdZnTe).This subject comes from the project authorized by the Beijing Institute of Spacecraft Environment Engineering.The objective is to develop a prototype for testing the principles of a new 3-layer 2×2 array CZT-based high-granularity calorimeter system.Meanwhile,this study also explores the applications of China-made CZT detector in the field of space energetic particle energy detection.So the detector used in this subject is a 10mm×10mm×1mm CZT one purchased from Shaanxi IMDETECK Technology Co.,Ltd.This study erects the front-end probe of the detector,develops the front-end amplification readout module and 12-channel data collection board card and upper computer collection control software.In the front-end probe and readout electronics research,this study considers the small size,light weight and low consumption of the space detector.Therefore,this study designs a 15cm×5cm×7cm aluminum framework equipped with a special geometric structure for supporting the detector and front-end electronics module.Relying on the geometric structure of probe,this study develops a 3.8cm×4.2cm front-end amplifier module that integrates the electronics readout channel and bias voltage input interface of the two-channel detector.Every readout channel includes charge-sensitive front-end amplifier circuit and main amplifier shaping circuit.The 12-channel collection board card is based on high-speed ADC(Analog to Digital Conventor)and logical FPGA(Filed Programble Gate Array).This 12-channel collection board card mainly completes the functions of the multi-channel analyzer to collect and transmit the signal data of 12-channel detector.Upper computer software IDE LabWindows/CVI base on NI completes the development of 12-channel data collection software,by the on/off,threshold setting,data processing and energy spectrum display of the upper computer software control detector collection system.In conclusion,this study completes the development of two front-end modules and 12-channel collUction system,and measures the energy resolution of 4-channel 241 Am γspectrum is respectively 10.43%,11.61%,10.99%and 10.33%with the China-made CZT detector.The difference of energy resolution is caused by the differences of readout electronics noises and detector current leakage.The integral nonlinear of the tested 4-channel collection system is less than 0.5%,and the maximum single-channel counting rate is 39.928Kcps..