Monte Carlo method for evaluation of surface emission rate measurement uncertainty  

作　　者：Yuan-Qiao Li Min Lin Li-Jun Xu Rui Luo Yu-He Zhang Qian-Xi Ni Yun-Tao Liu 

机构地区：[1]China Institute of Atomic Energy,Beijing,102413,China [2]National Key Laboratory for Metrology and Calibration Techniques,Beijing,102413,China [3]Department of Radiation Oncology,Hunan Cancer Hospital,Changsha,410031,China [4]The Affiliated Cancer Hospital of Xiangya School of Medicine,Central South University,Changsha,410031,China

出　　处：《Nuclear Science and Techniques》2024年第7期126-136,共11页核技术（英文）

摘　　要：The aim of this study is to evaluate the uncertainty of 2πα and 2πβ surface emission rates using the windowless multiwire proportional counter method.This study used the Monte Carlo method (MCM) to validate the conventional Guide to the Expression of Uncertainty in Measurement (GUM) method.A dead time measurement model for the two-source method was established based on the characteristics of a single-channel measurement system,and the voltage threshold correction factor measurement function was indirectly obtained by fitting the threshold correction curve.The uncertainty in the surface emission rate was calculated using the GUM method and the law of propagation of uncertainty.The MCM provided clear definitions for each input quantity and its uncertainty distribution,and the simulation training was realized with a complete and complex mathematical model.The results of the surface emission rate uncertainty evaluation for four radioactive plane sources using both methods showed the uncertainty’s consistency E_(n)<0.070 for the comparison of each source,and the uncertainty results of the GUM were all lower than those of the MCM.However,the MCM has a more objective evaluation process and can serve as a validation tool for GUM results.

关 键 词：Surface emission rate Monte Carlo method METROLOGY Probability distribution function Dead time Low-energy loss correction Least-squares method 

分 类 号：TL81[核科学技术—核技术及应用]