γ射线空气比释动能测量不确定度分析  

Uncertainty Analysis for Determination of Air Kerma in γ-ray Beam

作　　者：李德红[1] 成建波[1,2] 王培玮[1] 李兴东[1] 郭彬[1] 

机构地区：[1]中国计量科学研究院,北京100029 [2]兰州大学,甘肃兰州730000

出　　处：《计量学报》2016年第4期444-447,共4页Acta Metrologica Sinica

摘　　要：基于空气比释动能测量的Bragg-Gray 空腔理论,通过采用石墨空腔电离室对γ射线空气比释动能率进行测量,建立了测量数学模型,考虑到空气比释动能测量过程中的各影响量及其修正,采用实验测量或蒙卡模拟计算的方法得到各修正因子并分析不确定度, 得到γ射线空气比释动能测量的扩展不确定度约为0.5%,其中主要是由壁效应修正和平均电离功的不确定度贡献,因此有必要开展相应的研究,以提高空气比释动能的测量水平。Based on the Bragg-Gray cavity theory of measurements of air kerma for gamma ray, the air kerma rate is measured by using graphite cavity ionization chamber, and the mathematical model of measurement is established. The effect of influence quantities and its correction are taken into account during the process of uncertainty analysis for the measurement of air kerma. The correction factors and its uncertainty are gotten by using the methods of measurement and Monte Carlo simulation. The expanded uncertainty of gamma ray air kerma is about 0.5%, and that the mainly contribution of the uncertainty of gamma ray air kerma are come from the uncertainty of wall correction and average ionization power, so it is necessary to carry out the corresponding research, in order to improve the uncertainty level of the air kerma rate measurement.

关 键 词：计量学 不确定度分析 空气比释动能率 Γ射线 蒙特卡洛模拟 

分 类 号：TB98[一般工业技术—计量学]