Development Of A Single Probe Neutron/Gamma Discrimination Spectrometer

The application of nuclear technology has penetrated into every field of social development,and nuclear science and technology will bring some threats to human beings.It is a prerequisite for the safe application of nuclear technology to collect,process and analyze nuclear information accurately and effectively.Therefore,in order to deal with abnormal leakage of radioactive materials,while preventing the illegal transfer of nuclear materials and arbitrary.In this paper,a single probe neutron / gamma spectrometer is developed to monitor the special nuclear materials and radioactive materials in the sensitive control area.The traditional energy spectrometer or radiation screening instrument is usually used to build analog circuits with multiple probes to achieve the functions of filtering,pulse shaping,baseline recovery and peak detection.Because of the limitation of analog circuit and the principle of the traditional detector,it is difficult to achieve the desired results in many high-speed signal processing,especially in the identification and processing of the radiation ray.Therefore,the high-speed processing of digital nuclear signal has been an important research direction in the field of nuclear measurement.With the rapid development of high speed,high resolution ADC and digital programmable devices(FPGA,DSP)and the research and development of new EJ299-33 A probe.How to effectively utilize the new EJ299-33 A scintillator and the new screening algorithm to realize the energy spectrum analysis and nuclide identification in complex radioactive environment.The development trend of developing a new generation of nuclear instruments based on single probe ray discrimination spectrum measurement system.In this paper,on the basis of the existing research on single neutron/gamma probe can identify the nuclear signal spectrum in the process of realizing the acquisition and digital collection,radiation particle discrimination and spectrum analysis,carried out the FPGA nuclear data acquisition,nuclear signal processing chip FPGA algorithm design and Matlab neutron/gamma energy spectrum of neutron identification and off-line analysis research on key technology based on the research methods,the main contents are as follows:(1)Based on FPGA,the digital acquisition circuit of neutron / gamma discrimination nuclear signal is designed.The nuclear radiation pulse signal is directly connected to the high-speed ADC after the signal conditioning circuit,then the FPGA chip is used as the controller to complete the acquisition of the nuclear signal and the digital signal processing.(2)The design and implementation of FPGA algorithm for nuclear signal processing.With the help of Vivado,the design of pulse peak finding algorithm and the design of pulse width recognition algorithm are completed.The algorithm is implemented in FPGA and the logic of the control module is designed.It mainly includes ADC acquisition control module,pulse peak search module,pulse width recognition module,pulse amplitude analysis module and datas transmission module design.(3)Based on the mathematical model of the classification spectrum,the spectral characteristics of the nuclear signal pulses are extracted,and the initial energy spectrum of the pulse is analyzed.The feasibility of the verification of the classification spectrum in X-ray screening.In this paper,based on the development of a single probe neutron/gamma spectrometer,the main achievements are as follows:(1)The development of multifunctional integrated neutron/gamma detector for the determination of radioactive species and nuclide identification.In neutron/gamma mixed radiation field,neutron and gamma ray discrimination can be realized.The energy spectrum of the measured radiation is given in real time.(2)The radiation particle discrimination problem,using a new type of spectrum detector and mathematical model of ray type screening in FPGA,so as to effectively solve the traditional method using old-fashioned detector and analog circuit identification problem,at the same time,verify the type spectrum method has certain feasibility in nuclear signal processing.