| Fast NaI whole body counter is an important equipment used in the personal internal irradiation monitor and the measurement of fission and activation production which is produced by the nuclear power plant,reactor and offspring dealing factory. The internal irradiation monitor equipment includes three main processes:γspectrum measurement,γspectrum analysis and internal irradiation dose estimation.The equipment must be fast and compositive to satisfy the needs that a worker finished the monitor and the measurement within 2-3 minutes.Because the usual commercial software is difficult to alter a compositive system with the measurement and the dose estimation,so we developed the software(SAWBC)by ourselves.The software (SAWBC)includes these processes:data smoothing,background subtraction,peak searching,peak fitting and the analysis on nuclide and activity.This paper has given the deep study on some key technology,especially on the three parts:the creation and the improvement of continuum background subtraction,the creation and the optimization of D function peak searching method,the creation of IGFF function.The more details are as follows:a)Study on the barycenter method(5 points)and the polynomial least-squares method for data smoothing,And then providing the idea which several(N) channel can be combined before data smoothing.This can advance the calculation speed and decrease the possibility which the data result in aberration.b)Study on the continuum background subtraction method,considering the development of calculation speed,then providing the development method based on continuum background subtraction method.c)Improved the D function peak searching method with the D function differential,it can make the peak searching more precise.Based on the experiment and the analysis,the relationship between peak area and FWHM was provided,also,the method for solving the problem of overlap peak was provided.d)Studied the Gaussian fitting method,the Improved Gaussian Fitting Function (IGFF)was created based on solving the negative infection of human body scattering.IGFF employed a main Gaussian adding a correction term of low-energy tail Gaussian for fitting theγspectrum of whole body counter. With the IGFF fitting results and the compared analysis of theγspectrum of different source on different energy,the factor which infect the fitting veracity of IGFF method was provided,and,the compared fitting results between IGFF method and some other methods were also provided.e)An exclusive nuclide library was provided.It includes the important natural nuclides in human body,the familiar polluted nuclides and some other nuclides in the nuclear vocation.By compared the experiment results,the rules of nuclide judgment and region were also provided.f)Based on the fitting results of IGFF,the information of the nuclide library and the rules,the unknown nuclide and its activity can be known.g)Based on these theory and methods,the software of Spectrum Analysis on Whole Body Counter(SAWBC)was compiled with Vb flat.h)From the analysis results of SAWBC analyzing theγspectrum of whole body counter,we can see the systemic performance of SAWBC.
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