Design Of A Fault Monitoring And Recording Device For Nuclear Detector

With the development of nuclear energy,environmental radiation monitoring has been paid more and more attention.Nuclear detector for environmental monitoring of radiation protection and nuclear power plant is indispensable component in safety monitoring,its reliability is the important condition of the device is running[1].Nuclear detector output signal is different from the ordinary sensor,signal to noise ratio is low,the background noise is strong;Because of the bad work environment of high irradiation and high temperature,the instrument failure is frequent,wrong false positives,affecting the normal production;Digital is a trend of nuclear instrument at the same time,there is stable and reliable,automatic positioning requirement of fault intelligent diagnosis and rapid.Therefore,based on the National Natural Science Foundation of our research group,I learned from the research achievements of fault diagnosis research of nuclear detectors at home and abroad,combined with the latest development of computer and digital signal processing,digital signal in nuclear detector?A/D?based on the research of nuclear detector signal waveform characteristics of pulse output?signal parameters and relations?the change between the detector and the working conditions,to achieve the purpose of nuclear monitoring and recording fault detector.Developed a fault monitoring and recording nuclear detector device,the device has two working modes:mode?1?for nuclear signal digital acquisition and processing,the nuclear signal waveform and parameters?including mean value,mean square value,effective value,peak value etc.?.Working mode?2?for multichannel amplitude analyzer,will eventually become the original signal processing signal to the STM32 peak,STM32 peak of signal processing,finally get the gamma ray spectrum,and display color in the LCD.The device consists of a front-end analog circuit,a high speed A/D converter,a high performance micro controller STM32F407 and a LCD display module.The front-end circuit is mainly composed of a detector?Lanthanum bromide detector LaBr₃?Ce?,cadmium zinc telluride?CZT?detector?,signal amplifying and shaping circuit,peak detection circuit,high-speed A/D converter,the detector output signal into digital signal processing core end to the micro controller STM32F407.The LCD of LCD display module is driven by FSMC interface,and its advantage is that refresh speed is faster,thus achieving the requirement of waveform reappearance.The software design of the whole system adopts Keil5 develop software,and the interface design platform using emWin,including GUI programming part just call graphics libraries,thus shorten the overall development time.At the same time,SPI FLASH circuit and USB transfer circuit are added to store and upload data files to PC.Through theoretical analysis and experiment measurement,the whole system has a good performance,and it basically meets the expected expectation of the design.