Research And System Design Of Gamma Spectrum Analysis Method For Low-level Radioactive Aerosol Measurement

Radioactive aerosols mainly exist in the environment on which humans depend.They diffuse and diffuse in the environment with the atmosphere as a carrier,and are an important source of human body exposure and environmental pollution.Therefore,accurate measurement and analysis of radioactive aerosols in the environment is very important for radiation protection and environmental protection.In this thesis,the low-level radioactive aerosol measurement and gamma spectrum analysis methods are studied,and the corresponding system is designed and implemented.The main research contents of the thesis are as follows:(1)The sampling and measurement methods of radioactive aerosols are studied.Analyze the radioactive aerosol source item information to verify the feasibility of aerosol gamma spectrum measurement.In view of the low-level characteristics of aerosols,the sampling and measurement methods are compared and analyzed to realize the enrichment of aerosol samples and provide a data source for aerosol gamma spectrum analysis.(2)The analysis method of radioactive aerosol gamma spectrum is studied.Analyze key issues such as energy spectrum data smoothing,peak finding,background subtraction,peak area calculation,and focus on the peak finding method.An improved dual-scale correlation peak-finding method is proposed,which can effectively identify the spectral peaks with a high degree of overlap.Experiments show that the improved dual-scale correlation peakfinding method reduces the complexity of the algorithm,and compared with the traditional peak-finding method,the peak-finding effect is better.(3)Designed and implemented a radioactive aerosol measurement and gamma spectrum analysis system.Based on MATLAB,the aerosol gamma spectrum analysis system is designed to realize the qualitative and quantitative analysis of nuclides;the real-time monitoring system of environmental parameters is designed based on the ARM-Android platform.The system uses the ARM main controller for mobile collection of environmental parameters,and Bluetooth serial port Perform data wireless communication and host computer software for data analysis and processing to realize real-time display of environmental parameters,dynamic drawing of collected trajectories,and local data storage.(4)The influence of environmental parameters on the concentration of radioactive aerosol is studied.The correlation between nuclide level and environmental parameters was analyzed using mathematical statistical analysis software.Through a series of work such as theoretical research,algorithm analysis,program design,and system implementation,this thesis has completed the gamma spectrum analysis of the collected aerosol samples,real-time monitoring of environmental parameter information that affects the level of aerosol nuclides,and the analysis of the correlation between the two performing tasks,and using the system to analyze the measured data.The test results show that the gamma spectrum analysis system can accurately obtain the type and activity of the nuclide;the environmental parameter monitoring system can accurately monitor the changes of environmental parameters during the collection process in real time;the temperature,humidity,wind speed,and air pressure in the correlation analysis Affects the level of aerosol radionuclides.