摘要
几乎所有的科学活动都需要用不确定度对其进行评价。在解谱过程中,了解解谱过程中产生的不确定度对于评价解谱方法、丰富解谱结果等有着至关重要的意义。本研究的主要目的在于探讨利用蒙特卡罗(MonteCarlo,MC)法对中子多球谱仪测量不确定度进行评估的有效性。鉴于中子多球谱仪在计算过程中所涉及的复杂相关性和非线性特征,传统的基于理论模型和经验公式的不确定度分析方法已经不再适用。MC法通过对输入量的概率密度进行抽样,进而获得输出量的概率密度分布,因此能够有效地处理复杂系统和非线性问题,从而获取计算结果的统计特性。本研究结合了具体实例和实验结果,详细介绍了运用MC法评估多球谱仪测量不确定度的具体步骤和过程,采用多球中子能谱仪和中子场标准装置(包含4个中子源)开展了实验测量,评估了30cm铁球屏蔽下的中子注量率谱的测量结果。测量结果显示其分布均在期望值的±5%以内,表明该方法能够为多球谱仪测量的准确性和可靠性提供可靠的评估,也为相关研究提供了有益的参考。
[Background]Multisphere neutron spectrometers are pivotal in accurately measuring neutron flux across various fields.The inherent complexities and non-linearities in their calculation processes,such as correlated variables,make traditional uncertainty analysis methods based on theoretical models and empirical formulas(e.g.,the GUM(Guide to the Uncertainty in Measurement)method)unsuitable.[Purpose]This study aims to demonstrate the application of the Monte Carlo(MC)method as an effective tool for evaluating measurement uncertainty in multi-sphere spectrometers,addressing the challenges posed by complex systems and non-linear problems.[Methods]First of all,the MC method was employed to conduct probability density sampling of input variables to obtain the probability density distribution of the output variables.Detailed statistical characterization of the calculation results was allowed to provide a more comprehensive understanding compared to conventional methods.Then,numerous simulations were performed to take into account of variability and uncertainty in the input parameters,hence the robustness of the analysis was enhanced.Consequently,this technique overcome the limitations of traditional deterministic approaches,offering more reliable and nuanced insights into the system's behavior.Finally,experiments were carried out using multisphere neutron spectrometers and neutron field standard device(including 4 neutron sources),and the measurement results of neutron flux spectrum under 30 cm iron ball shielding were evaluated using above-mentioned method.[Results]The spectrum unfolding results obtained by this method have a total uncertainty of 5%in the energy group of interest after being passed by the spectrum unscrambling program.[Conclusions]The application of the MC method offers a robust framework for the assessment of measurement uncertainties in multi-sphere neutron spectrometers.This study not only enhances the accuracy and reliability of spectrometer measurements,but also contributes to the broader field of neutron measurement techniques by providing a reference for the evaluation of complex systems.
作者
张大可
唐智辉
韦应靖
李桃生
曹勤剑
孙博文
ZHANG Dake;TANG Zhihui;WEI Yingjing;LI Taosheng;CAO Qinjian;SUN Bowen(Institute of Health Physics,China Institute for Radiation Protection,Taiyuan 030006,China;Shanxi Provincial Key Laboratory of Radiation Safety and Protection,Taiyuan 030006,China;Key Laboratory of Radiation Protection Technology of China National Nuclear Corporation,Taiyuan 030006,China;Key Laboratory of Neutron Transport Theory and Radiation Safety,Institute of Nuclear Energy Safety Technology,Chinese Academy of Sciences,Hefei 230031,China)
出处
《核技术》
EI
CAS
CSCD
北大核心
2024年第12期63-72,共10页
Nuclear Techniques
基金
中国辐射防护研究院自主科研项目创新团队基金(No.YC24010102)资助。
关键词
蒙特卡罗法
不确定度评定
中子谱仪
Monte Carlo method
Uncertainty rating
Neutron spectrometer
