Research On Multi-channel Nuclear Pulse Acquisition Spectralization Technology Of Detector Array

A large amount of radioactive solid waste will be generated in all aspects of the production and application of the nuclear industry.Usually,nuclear waste barrels are used for complete storage.In the process of nuclear waste barrel treatment and disposal,it is necessary to conduct radioactive detection.At present,the ideal detection method is to perform non-destructive detection and analysis of radioactive materials.And other important information.In the detection of radioactive nuclear waste barrels,the detection efficiency of a single detector is low and the time is long.The detection method of the detector array can improve the detection efficiency.Based on this,the paper proposes to use the detector array as the detection module to carry out relevant research on the acquisition and processing of nuclear pulse signals.The main research contents are as follows:(1)Proposed a parallel method of multiple sodium iodide(Na I)detectors,each probe independently collected nuclear pulse signals,developed a nuclear pulse signal acquisition system based on FPGA,and realized Cs-137 under the 20 MHz system clock High-speed acquisition of pulse signals.(2)Digitally process the nuclear pulse signal.Realize the nuclear pulse signal ladder forming and Gaussian forming,respectively,and compared the two methods.According to the digital recursive formula of S-K filter circuit,the Gaussian forming parameters are selected,the performance parameters are optimized,and the influence of different forming parameters on energy resolution is studied.To verify the implementation method of digital Gaussian shaping in FPGA.(3)Using MATLAB platform to carry out the research on the spectral performance of nuclear pulse signals.The pulse signal after the Gaussian filter shaping process is studied for baseline recovery,stacking discrimination and amplitude extraction,and finally the spectrum is formed.(4)Qualitative and quantitative analysis of the energy spectrum to realize the identification of radionuclides in nuclear waste barrels.The innovation of this paper is as follows: the digital shaping process is carried out on the collected nuclear pulse signals,the results under different shaping methods and shaping parameters are analyzed and evaluated,and the energy spectrum obtained by the proper shaping method is expanded.In summary,this paper studies the nuclear pulse signal spectrum formation technology,and realizes the high-speed acquisition and spectrum formation of the pulse signal.Perform digital forming processing analysis on the pulse signal,optimize performance parameters,and use the Cs-137 standard source to test the forming algorithm,energy spectrum display,and energy resolution to complete the qualitative and quantitative analysis of the energy spectrum.The experimental results show that the energy spectrum display effect is good and the system performance is accurate and reliable.