Multiscale Modeling of Plasma Surface Interactions with Coupled Boundary Plasma Physics*

This talk presents results of a coordinated, multiscale project to develop and deploy validated, high-performance computational codes to predict the boundary plasma and the evolving surfaces of plasma facing components (PFC). A focus is on the sub-surface gas dynamics in tungsten, which influence tritium retention and material surface evolution, as well as the computational framework for coupling the boundary plasma physics to the surface response. Our approach to modeling PFC surface response is based on simultaneously attacking this problem from both a “bottom-up” atomistic approach, as well as from a “top-down” continuum perspective that focuses on kinetic models of species reactions and diffusion. This presentation will also introduce a new, depth dependent surface characterization technique to validate the multiscale models of sub-surface D-He gas dynamics in tungsten. The presentation concludes with a perspective on divertor and PFC performance in fusion devices beyond ITER.