Development Of Artificial Radionuclide Monitoring Device Based On Time Interval Analysis

During the operation or production process of nuclear devices in nuclear power plants and other nuclear related sites,U,Pu and corresponding fission products may diffuse into the air and attach atmospheric dust to form radioactive aerosols.Among them,U,Pu and other toxic nuclides with long half-life are most of them α Decay,the formation of aerosols in the atmosphere,diffuse into the air,once inhaled will harm human health.Therefore,how to deduct the serious interference of radon and its daughter products in the environment is the key technology of artificial radionuclide(such as U,Pu)measurement,and also the current research hotspot.Decay measurement method,particle size separation method,particle size separation method are usually used at home and abroad α—β Ratio method,false match method,analytical method and energy screening method are used to deduct the interference of natural background radon and its daughters in the environment.For example,due to the interference of the self absorption of the sample,the radon progeny can not be detected by the energy spectrum method α The energy of the particles decreases and the energy of the particles decreases α The counting of particles and the distribution of particles in natural sites α The counting has a certain proportional relationship,so the counting compensation is carried out in the natural channel,but the detection sensitivity is affected by the fluctuation of the compensation coefficient.In order to solve these problems,this paper proposes a method based on artificial radionuclide mother daughter cascade decay(β—αdecay).The time spectrum can be directly extracted from 214bi-214 po related events,so as to accurately measure the concentration of natural radionuclides,which is not affected by energy "tailing",and can be used to deduct the interference of natural radionuclides,Rapid and effective measurement of artificial radionuclide concentration.The measurement time of this device can reach 10 minutes,which can quickly and effectively measure the artificial radionuclide concentration.Moreover,the time interval analysis method is not sensitive to the background fluctuation,and has less demand for source and background information,which can be used for weak radioactivity detection.In this paper,the device is suitable for early leakage detection in nuclear related sites.This paper constructs a set of preliminary experimental device,which is composed of composite crystal detector,m2 i.2021 high data acquisition card with time stamp function,nuclear data processing circuit board,industrial control computer,high voltage power supply,upper computer software,etc.After the signal is detected by the composite crystal detector,the signal is further amplified by the front amplifier and the main amplifier circuit.After peak detection,the signal is transmitted to the upper computer software for analysis by the high-speed data acquisition card.In this paper,visual studio 2012 is used for graphical interface design,and C # language is used for programming.It mainly realizes the acquisition of nuclear pulse time series and the extraction of time stamp of high-speed data acquisition card.In the data processing part,the concentration of natural radionuclide is measured by time interval analysis,and the concentration of artificial radionuclide is measured.In this study,the time interval analysis and measurement of artificial radionuclides were preliminarily constructed,and the device was preliminarily verified.It lays a foundation for the development of high sensitivity monitor for artificial radionuclides(such as U,Pu).