计算α本征值的蒙特卡罗期望估计方法  

Monte Carlo expected estimation method for α eigenvalue calculation

作　　者：王瑞宏[1] 黄正丰[1] 江松[1] 裴鹿成[2] 

机构地区：[1]北京应用物理与计算数学研究所,北京100088 [2]中国原子能科学研究院,北京102413

出　　处：《核科学与工程》2008年第3期204-209,223,共7页Nuclear Science and Engineering

基　　金：国家自然科学基金资助项目(10771018)

摘　　要：从齐次中子输运方程出发,推导了计算α本征值的数学表达式,并给出了三种蒙特卡罗期望估计式,它们分别是:径迹长度期望估计;碰撞期望估计;逃逸期望估计。不同模型的计算结果表明,期望估计方法的计算效率可比MCNP中的(α,k)回归迭代方法有量级的提高。尤其对含慢化材料的次临界模型,期望估计方法有着特殊的优势。From the basic homogeneous integro-differential equation of neutron transport, three Monte Carlo expected estimator formulations of a based on the eigen-solution are derived. They are Collision estimator, Path-length estimator and Escaping estimator respectively. The unbiased estimation values can be calculated in the process of Monte Carlo simulation. Related numerical results are shown about a specific model and a benchmark model. The calculation efficiency of the Expected Estimation Method is higher than （α,k） iteration method. In special, the new method has advantages in the calculation of sub-critical model with hydrogen material.

关 键 词：α本征值 MONTE CARLO方法 碰撞期望估计方法 径迹期望估计方法 逃逸期望估计方法 

分 类 号：TL32[核科学技术—核技术及应用]