Dynamic simulation of erosion and redeposition on plasma-facing materials

A dynamic Monte Carlo simulation code, erosion and deposition based on a dynamic model ( EDDY), which combines ion reflection and sputtering of plasma-facing materials with transport of released particles in plasma, is developed. The surface composition changes due to impurity deposition, collisional mixing, and thermal diffusion of the deposited impurities at elevated temperatures are taken into account. Ionization and dissociation of released atoms and molecules and their gyromotion in the plasma are calculated, so that prompt and local redepositions are simulated. This enables the simulation of erosion and redeposition patterns, and the impurity depth profiles of plasma-facing materials. Recent applications to analyses of plasma-wall interactions in existing fusion devices are presented.