The Measurement And Analysis Of Influence Based On γ Energy Spectrum

Most of the radioactive nuclides can emit γ-rays in their process of decay. The γ-raycarries a specific characteristic energy and it usually has a strong penetration capability.Therefore, it is of great significance to detect and analyze γ spectrum in the environment forradiation protection. The main work of this study is to measure and analyze the flux of γspectrum by using both experiment and simulation methods.BH1936Low background multi-channel γ spectrometer as well as mixed sources of⁶⁰Coand¹³⁷Cs is used in the experiments. The mixed sources of⁶⁰Co and¹³⁷Cs is taken as knownenergy source to calibrate the γ spectrometer before it used to measure the measurementefficiency of⁴⁰K,²²⁶Ra,²³²Th and²³⁸U in the soil. The energy spectrum analysis is also madefor samples from the environment. The analysis mainly focuses on radioactivity of buildingmaterials and soil. specific acticity of standard sources⁴⁰K,²²⁶Ra,²³²Th and²³⁸U are obtainedand radioactivity of γ-ray was calculated and analyzed in the paper.Apart the experiments, simulation models are also constructed by Monte Carlo methodto simulate the measurement efficiency of NaI（Tl） detector in response to different γ energyspectrums. Based on the energy spectrums of⁶⁰Co,¹³⁷Cs and⁴⁰K measuring fromexperiments, the broadening parameters of energy spectrum can be determined. The energyspectrums obtained through experiment and simulation will match better by further adjustingthe parameters and size of crystal in detector.The response functions of monoenergetic photon with different energy spectrums can bethen acquired through MCNP simulation. The response matrix resulted from responsefunctions by interpolation method is resolved to get actual flux spectrum with MATLAB tooland finally the spectrum analysis is completed.