基于计数辅助树的蒙特卡罗粒子输运计算大规模计数方法  

Tally assist tree-based method for scoring massive tallies in Monte Carlo particle transport calculation

作　　者：张澍[1,2] 郝丽娟[2] 宋婧[2] 吴斌[2] 孙光耀[2] 

机构地区：[1]中国科学技术大学核科学技术学院,合肥230027 [2]中国科学院核能安全技术研究所中国科学院中子输运理论与辐射安全重点实验室,合肥230031

出　　处：《核技术》2016年第10期58-63,共6页Nuclear Techniques

基　　金：中国科学院战略性先导科技专项(No.XDA03040000);国家自然科学基金(No.11305203);国家磁约束核聚变能发展研究专项(No.2014GB1120000)资助~~

摘　　要：传统的蒙特卡罗粒子输运计算程序在粒子每一步模拟结束后,通过遍历所有计数器来判断当前粒子所在栅元是否需要进行计数,该过程耗时随计数器数量的增加近似线性增长,当计数器数量较大时,计数耗时远高于输运耗时。本文发展了一种基于计数辅助树的大规模计数加速方法,建立了与几何栅元一一对应的树形结构,并在节点中存储了相应栅元的计数信息,通过当前粒子所在栅元的几何信息从树中快速读出对应的计数器。为了验证该方法的有效性,基于Hoogenboom全堆基准例题测量了不同计数器数量下的计算耗时。测试结果显示本文方法能有效地提高大规模计数问题的计算效率。Background： Traditional Monte Carlo particle transport calculation codes traverse all the tally cards to find which tallies should be scored at the end of each simulation step. The run time of this procedure almost grows linearly with the number of total tally number. When the tally number is large, the tally procedure costs far more time than the transport calculation.Purpose： This paper proposed a tree-based method for scoring massive tallies. Methods： The method builds a tally assist tree that all the nodes map one-for-one to the geometry cells. All the tally information read from the input file is stored in the tree. At the end of each simulation step, by mapping the geometry information of the cell where the particle is currently in to a node in the tree, the tallies need to be scored is directly retrieved from the node.Results： To test the proposed method, the run time of the Hoogenboom benchmark reactor model with different tally numbers is measured.Conclusion： The results show that this method can improve the computation efficiency of massive tally problems.

关 键 词：蒙特卡罗 粒子输运 计数辅助树 大规模计数 

分 类 号：TL329.2[核科学技术—核技术及应用]