随机数片段长度溢出对MCNP模拟计算的影响分析  

Analysis the Effect of the MCNP Simulation Calculation when Random Number Stride Exceeded

作　　者：赵永生[1,2] 邓中华 颜瑜成[1,2] 张俊奎 

机构地区：[1]成都理工大学工程技术学院,四川乐山614000 [2]核工业西南物理研究院,成都610041 [3]同方威视技术股份有限公司,北京100085

出　　处：《核电子学与探测技术》2017年第6期595-598,共4页Nuclear Electronics & Detection Technology

基　　金：乐山市重点科技计划课题(A322013006)

摘　　要：为了保证串行和并行计算结果的一致性,MCNP模拟计算中子输运中对历史追踪用到的随机数通常采用分段法进行分配。如果分段长度不足则会导致总随机数序列的均匀性受到破坏。本文采用MCNP模拟计算反应堆的中子增殖过程中沉积能量,通过调整stride溢出程度大小,分析均匀性受到破坏的随机数序列对裂变沉积能量的影响。模拟计算结果表明在此情况下不会导致得出错误的裂变沉积能量,这一结果与MCNP5英文手册的描述是一致的。此外,本文还从MCNP模拟计算原理的角度解释了产生这种结果的原因,以及导致不可预估方差的原因。For keeping the consistency of calculation in serial and parallel Monte Carlo calculations,the random numbers used in the tracking of history are distributed by segmentation in the neutron transport simulation. The Uniformity and independence of the random number sequence was damaged when the stride was exceeded. In this paper,the energy deposition of fission production in a reactor was calculated by MCNP. In this case,the exceeding the stride does not result in wrong answers. It was consistent with MCNP Version 5 manual. In addition,the reasons for this result were also explained in the light of the principle of MCNP simulation in this work. The reasons for resulting in an underestimate of the variance were explained too.

关 键 词：随机数 片段溢出 MCNP 均匀性 

分 类 号：TL81[核科学技术—核技术及应用]