The Modeling Of Full Spectrum Data Of The Scintillation Gamma-ray Spectrometer By Monte Carlo

Multi-channelγspectrum of ionizing radiation measurements in the environmental assessment or detection of radioactive contamination is highly efficient and accurate way, since the 1986 Chernobyl accident has been widely used. NaI (Tl) gamma-ray spectrometer with high efficiency, can be used at room temperature, and other characteristics, in the air and in-site measurements in the application of broad spectrum, but its crystal energy resolution is not high, leading to artificial radionuclide the ¹³⁷Cs And ²³⁸U of ²¹⁴Bi and ²³²Bi and ²³²Th peak of ²⁰⁸Tl overlap, artificial isotope cesium extraction more difficult. Therefore, how quickly and accurately extract of the radionuclide ¹³⁷Cs useful information to enhance NaI (Tl) scintillator detector gamma-ray spectrometry quantitative data to explain the importance of accuracy.This paper applications Monte Carlo method, using MCNP procedures DigiDART sodium iodide gamma-ray spectrometer measurement of the soil natural radionuclides ²³⁸U, ²³²Th, 40K and artificial radionuclides ¹³⁷Cs for the quantitative analysis.In previous papers on the basis of the efficiency of detection equipment were re-calculated, and with the efficiency of detection equipment response function. In the simulation process of amending the geometry of the probe and the material composition, laboratory equipment closer to the real equipment.Simulation of the 137Cs point source from the detector 10 cm from the analog spectrum, by increasing the simulation time to improve the accuracy of the simulation data. Analog spectrum than measured in the low-low spectrum, the two main peak in good agreement, the two relative error of 30 %.Yuen joined the simulation of the radionuclide more energy to raise the low end of the Compton scattering count. At the same time, consider the photoelectric effect and electronic effects, makes simulation results can be closer to the real measurement. Through the study on a method to the value of simulation, amended the expansion factor, makes analog spectrum close to the measured spectrum. More than 583keV numerical simulation of the characteristic peaks and measured the spectrum characteristic peak values similar error at 20%. 583keV below the peak of several features of Compton scattering Ping lower than the actual value, but peak corresponds better.