Development Of Gamma Nuclide And Neutron Patrol Instrument Based On WinCE System

In view of the nuclear accidents caused by the continuous development of nuclear technology in life and the monitoring of radioactive substances in the environment,radionuclide identification is to carry out nuclide analysis and detect the safety of nuclear facilities.Radiation protection and effective means of preventing the occurrence of nuclear terrorism.In order to make the instrument convenient and integrated,the testing equipment of large nuclear instrument has been gradually developed into a miniaturized and portable radionuclide identification instrument with the main functions of processing spectral line data and so on.In this paper,the two-inch NaI?Tl?crystal and the ultra-thin Cs₂LiYCl₆?Ce??CLYC?crystal are coupled to each other as a composite detector to collect the original nuclear pulse signal.The digital multi-channel pulse amplitude analyzer is transformed into energy spectrum data to be stored in the FIFO of stm32.The core board card with wince system is used for data exchange through serial port transmission.Finally,the application program is developed based on WinCE system,implementation of spectral analysis algorithm encapsulation,spectral line drawing and information display.The application program is written in visual studio 2008 integrated development environment with embedded platform,and the analysis algorithm is verified by MATLAB in advance.The main contents and achievements of this thesis are as follows:?1?Detector design:the neutron measurement is carried out by coupling an ultra-thin CLYC crystal on the crystal NaI?Tl?in the common gamma energy spectrometer.The physical characteristics and detection principle of NaI?Tl?crystal and CLYC crystal are introduced,and the original pulse signal of the composite crystal is tested.The difference of the original pulse signal between the NaI?Tl?crystal and the CLYC crystal is analyzed,and the feasibility of using the detector as the detector of gamma and neutron measurement is also analyzed.?2?The main control board of the host computer:the hardware control board and the operating system suitable for the whole system are compared and analyzed.The S5PV210 embedded core board with Windows CE operating system is used as the upper board,and the serial port is used for data transmission.Three additional serial ports are reserved,SD card interface is reserved,and one USB2.0 interface is used for data backup.Cut the redundant interface and make a compact main control backplane to reduce the overall power consumption.?3?Software design:the spectrum analysis software is developed based on wince system,and the related items of application program development in wince system are introduced in detail.The software algorithm mainly includes the original spectral data smoothing,smooth spectral line peak finding,nuclide identification,and so on.Nuclear library design and other parts;The function part has spectral line data acquisition,parameter setting,data storage and so on.Through the way of serial communication,the data interaction between the upper computer software and the hardware of the lower computer is realized.The Least Square Fitting method is used to realize the smooth de-noising of the original spectral line.The method of finding peak and characteristic peak energy ratio by symmetric zero area method is used to realize nuclide identification.Using a large-capacity memory card,can achieve the storage of tens of thousands of 1024 channels of data.?4?System test:the composite detector coupled with,NaI?Tl?crystal and CLYC crystal can meet the requirements of gamma radionuclide and neutron patrol instrument.The spectral data processing algorithm used in the instrument realizes the correct identification of ¹³⁷Cs and ⁶⁰Co.In the software,the functions of energy spectrum display,dose rate display,neutron measurement,over threshold buzzer alarm and nuclide identification are designed.The results show that the instrument can identify the basic nuclides accurately and quickly.