Angular Distribution of Particles Emerging from a Diffusive Region and its Implications for the Fleck-Canfield Random Walk Algorithm for Implicit Monte Carlo Radiation Transport

Cooper, M.A.

Lawrence Livermore National Laboratory

关键词: Angular Distribution;    Transport;    Transport Theory;    72 Physics Of Elementary Particles And Fields;    Radiation Transport;   

DOI  :  10.2172/793970
RP-ID  :  UCRL-ID-139692
RP-ID  :  W-7405-Eng-48
RP-ID  :  793970

美国|英语

来源: UNT Digital Library

【 摘 要 】

We present various approximations for the angular distribution of particles emerging from an optically thick, purely isotropically scattering region into a vacuum. Our motivation is to use such a distribution for the Fleck-Canfield random walk method [1] for implicit Monte Carlo (IMC) [2] radiation transport problems. We demonstrate that the cosine distribution recommended in the original random walk paper [1] is a poor approximation to the angular distribution predicted by transport theory. Then we examine other approximations that more closely match the transport angular distribution.