Monte Carlo method for determining the response of portable gamma detector for in situ measurement of terrestrial gamma ray field  

作　　者：Boubaker Askri 

机构地区：[1]Department of Physics, College of Science, Qassim University [2]Research Unit of Nuclear Physics and High Energy, Faculty of Sciences of Tunis, University of Tunis El Manar

出　　处：《Nuclear Science and Techniques》2016年第4期28-37,共10页核技术（英文）

摘　　要：A Monte Carlo method to study the response of portable detector to terrestrial gamma ray is proposed. This method is based on two-stage Monte Carlo simulation.First, the probability distributions of the phase space coordinates of the events that are most likely to be detected are reconstructed at the phase space shell level. The phase space shell is a closed surface enclosing the detector. The detector response to events originating from the phase space shell is then studied. The full absorption spectra as well as the partial absorption spectra are obtained for natural radionuclides uniformly distributed in the ground. For validation, this method is applied to a Hp Ge portable detector previously studied. The previous study is based on a semiempirical model. Good agreement is achieved when we compare the full-energy peak efficiencies and the total in situ spectra obtained by the two methods. As an application, the effective depth of the activity of the^(137) Cs artificial radionuclide in the soil is determined from the low-energy part of the total in situ spectrum.A Monte Carlo method to study the response ofportable detector to terrestrial gamma ray is proposed. Thismethod is based on two-stage Monte Carlo simulation.First, the probability distributions of the phase spacecoordinates of the events that are most likely to be detectedare reconstructed at the phase space shell level. The phasespace shell is a closed surface enclosing the detector. Thedetector response to events originating from the phasespace shell is then studied. The full absorption spectra aswell as the partial absorption spectra are obtained for naturalradionuclides uniformly distributed in the ground. Forvalidation, this method is applied to a HpGe portable detectorpreviously studied. The previous study is based on asemiempirical model. Good agreement is achieved whenwe compare the full-energy peak efficiencies and the totalin situ spectra obtained by the two methods. As an application,the effective depth of the activity of the 137Csartificial radionuclide in the soil is determined from thelow-energy part of the total in situ spectrum.

关 键 词：伽玛探测器 蒙特卡洛方法 便携式 地面 相空间重构 测量 线场 测定 

分 类 号：O571.323[理学—粒子物理与原子核物理]