计算物理 ›› 2016, Vol. 33 ›› Issue (6): 639-644.

• 研究论文 • 上一篇    下一篇

非定常输运模拟中基于粒子标识分类的源偏倚算法

上官丹骅, 许海燕   

  1. 北京应用物理与计算数学研究所, 北京 100094
  • 收稿日期:2015-09-07 修回日期:2016-03-03 出版日期:2016-11-25 发布日期:2016-11-25
  • 作者简介:上官丹骅(1977-),男,博士,副研究员,从事蒙特卡罗算法及应用研究,E-mail:sgdh@iapcm.ac.cn
  • 基金资助:
    中国工程物理研究院科学基金(2014B0202029)资助项目

Particle-Flag Based Source Bias Algorithm for Simulating Time-Dependent Particle Transport

SHANGGUAN Danhua, XU Haiyan   

  1. Institute of Applied Physics and Computational Mathematics, Beijing 100094, China
  • Received:2015-09-07 Revised:2016-03-03 Online:2016-11-25 Published:2016-11-25

摘要: 在非定常输运问题的多步蒙特卡罗模拟中,根据粒子的不同属性进行标识分类可以得到非常细致的系统相关标识物理量.对于某些目标标识物理量,模拟的样本中造成有效贡献的样本相对较少,导致这些物理量模拟结果的涨落较大,而单靠增加总样本数不能高效地使有效样本达到一个合理的水平.本文提出一种基于标识分类的源偏倚算法,将增加的所有样本定向赋予目标类粒子,从而高效地降低目标标识物理量的统计误差且不影响非目标标识物理量的计算.以一维多层介质非定常输运模型验证上述结论.

关键词: 非定常输运问题, 蒙特卡罗方法, 标识, 源偏倚

Abstract: In multi-step Monte Carlo simulation of time-dependent particle transport problems, particle-flag based physical quantity can be calculated by appropriate classification of diverse particle's attributes. Some particle-flag based physical quantities' fluctuation are strong since only very small fraction of total histories can make non-zero contribution and it is inefficient to deal with this problem by increasing purely total history number. A source bias algorithm is proposed to decrease stochastic error of target quantity by increasing number of source particle with a specific type only. Meanwhile, precision of non-target quantities are hardly decreased. A one-dimensional multi-layer model is utilized to display effect of the method.

Key words: time-dependent particle transport, Monte Carlo method, particle-flag, source bias

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