The Transport Equation in Optically Thick Media: Discussion of IMC and its Diffusion Limit

Szoke, A.¹  Brooks, E. D.¹ 

[1] Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

关键词: Implicit Monte Carlo;    Radiation transport;    Diffusion limit;   

DOI  :  10.2172/1289358
RP-ID  :  LLNL--TR-697860
PID  :  OSTI ID: 1289358

学科分类：物理（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

We discuss the limits of validity of the Implicit Monte Carlo (IMC) method for the transport of thermally emitted radiation. The weakened coupling between the radiation and material energy of the IMC method causes defects in handling problems with strong transients. We introduce an approach to asymptotic analysis for the transport equation that emphasizes the fact that the radiation and material temperatures are always different in time-dependent problems, and we use it to show that IMC does not produce the correct diffusion limit. As this is a defect of IMC in the continuous equations, no improvement to its discretization can remedy it.