ExASIM: Robust Platform for Modeling Plasma Material Interactions

ExASIM is a framework that provides a computational conjunction of atomistic simulations with advanced MD and multi-component BCA calculations to handle complex reactive and geometric systems efficiently.  It is used to study W-based complex alloys under conditions relevant to fusion plasma-materials interactions (PMI). It allows for more accurate simulations by prioritizing simulation techniques in appropriate energy, spatial and temporal physical regimes according to the PMI conditions studied. ExASIM generates surfaces with specific properties (Porosities, crystal structures, and grains). Then, it reduces surfaces to simple components such as: grain boundaries and materials interfaces. Modeling simple components is performed by fast BCA simulations using DYNAMIX. While for non-uniform components, complex interfaces, and low energy ion irradiation, LAMMPS is used for atomistic simulations. Simulations are iterated to determine self-interactions and at the final stage, results of the individual components from LAMMPS and DYNAMIX are coupled to reconstruct the resulting total surface. This platform is used to model irradiation of N and Ar beams with fluence of 10¹⁷ cm^-2 incident on pure and porous W at 500 eV and 1 keV at 0^o, 45^o and 70^o angles of incidence.