基于自动重要抽样方法的减方差技巧体系构建与验证
Construction and Verification of Variance Reduction Technique System Based on Automatic Importance Sampling
武祯 1郝以昇 2浦彦恒 2周扬 2杲申申 2邱睿 2马锐垚 2张辉 2李君利2
作者信息
- 1. 清华大学工程物理系,北京 100084;粒子技术与辐射成像教育部重点实验室,北京 100084;同方威视技术股份有限公司,北京 100084
- 2. 清华大学工程物理系,北京 100084;粒子技术与辐射成像教育部重点实验室,北京 100084
- 折叠
摘要
屏蔽计算问题根据求解目标不同一般可分为源-探测器问题、区域问题和全局问题.MCShield研究团队针对3类问题中存在的深穿透问题提出了相应的减方差技巧,本文以此为基础构建了基于自动重要抽样(AIS)方法的减方差技巧体系,并开展了验证工作.针对源-探测器问题,采用NUREG/CR-6115 PWR压力容器计算基准题对小探测器自动重要抽样(SDAIS)方法进行验证.结果表明,SDAIS方法的计算效率约为AIS方法的7倍.此外还提出并验证了基于AIS伴随蒙特卡罗的耦合减方差(AIS-CADIS)方法,将AIS方法引入到蒙特卡罗伴随计算中,取得了良好的效果.针对全局问题,提出网格化-AIS方法并使用简化反应堆屏蔽计算算例进行验证,结果表明,网格化-AIS方法的计算效率是AIS方法的12倍左右,是直接蒙特卡罗方法的290倍左右.
Abstract
According to different objectives,shielding calculation problems can be divided into regional problem,source-detector problem,and global problem.To solve the deep penetration problem of the three kinds of problems,the MCShield research team systematically proposed a series of variance reduction methods.According to these works,this article constructed a variance reduction technique system based on the automatic importance sampling(AIS)method,and conducted some verification work.For the source-detector problem,the NUREG/CR-6115 PWR pressure vessel calcula-tion benchmark was used to verify the small detector automatic importance sampling(SDAIS)method.The result shows that the SDAIS method is more efficient than the AIS method for the source-detector problem.In addition,an AIS-based Monte Carlo coupled variance reduction(AIS-CADIS)method was also proposed which introduces the AIS method into Monte Carlo adjoint calculations and was verified against bench-mark problems.For global problems,the grid-based AIS method was proposed and verified using a simplified reactor shielding calculation problem.The results show that compared with the AIS method and analog Monte Carlo methods,the grid-based AIS method can improve calculation efficiency.
关键词
蒙特卡罗/自动重要抽样方法/减方差技巧/MCShield程序Key words
Monte Carlo/automatic importance sampling method/variance reduction technique/MCShield program引用本文复制引用
基金项目
中国辐射防护研究院平台发展基金(YP21030101)
国家自然科学基金面上项目(12175114)
国家自然科学基金面上项目(U2167209)
出版年
2024
国家科技期刊平台
NSTL
万方数据