Non deterministic methods for charged particle transport

Abstract

The coupling of Monte-Carlo methods for solving Fokker Planck equation with ICF codes requires them to be economical and to preserve gross conservation properties. Besides, the presence in FPE of diffusion terms due to collisions between test particles and the background plasma challenges standard M.C. techniques if this phenomenon is dominant. We address these problems through the use of a fixed mesh in phase space which allows us to handle highly variable sources, avoiding any Russian Roulette for lowering the size of the sample. Also on this mesh are solved diffusion equations obtained from a splitting of FPE. Any non linear diffusion terms of FPE can be handled in this manner. Another method, also presented here is to use a direct particle method for solving the full FPE.