摘要
Abstract
To meet the special application requirements in the fields of radiation environment monitoring,nuclear emergency,and radioactive geophysical survey in China,the article developed a vehicle-mounted γ energy spectrum acquisition system based on NaI crystal.The system uses the NaI detector to convert the γ-ray signal into an electrical pulse signal,and conditioning circuits such as pre-amplification,pole-zero phase cancellation,S-K filter shaping,gain adjustment,and so on,was designed to process the original signal of the NaI detector and obtained a quasi-Gaussian waveform;then the spectral data were obtained by digitizing the pulse signal through a multi-channel pulse amplitude analyzer;after then,a set of upper computer analysis software was developed to analyze the spectral data.Finally,a set of upper computer analysis software was developed to analyze,process and display the spectral data,which realized the activity measurement,real-time nuclide identification and digital spectroscopy.In order to solve the problems of low resolution and spectral drift of the existing vehicle-mounted γ-energy spectrometer,an automatic passive stabilization algorithm was proposed to improve the energy resolution and the linearity of the vehicle-mounted γ-energy spectrometer,which improved the accuracy of the measurement data.The experimental results showed that the device can accurately and rapidly carry out energy spectrum analysis and radioactivity detection,with a high resolution of 1 024 channels,energy resolution of 8.06%(137Cs),and the peak drift of the 1.461 MeV energy spectrum of 40K is not more than±1 channel,and has the advantages of fast measurement speed,high detection accuracy,real-time positioning,etc.,which are need in the field of nuclear emergency response and nuclear radiation environmental protection.Therefore,the designed system has a wide range of application prospects in the field of nuclear emergency and nuclear radiation environmental protection.关键词
放射性地球物理勘查/车载γ能谱采集/多道脉冲幅度分析器/自动无源稳谱Key words
radioactive geophysical survey/vehicle-mounted γ spectrum acquisition/multi-channel pulse amplitude analyzer/automatic passive spectrum stabilization分类
能源科技
