Integrated Multi-Scale Modeling of Impurity Migration and Plasma-Facing Material Evolution in Present and Future Tokamaks*

Finding suitable plasma-facing materials is one of the great challenges in designing future fusion reactors, as unprecedented heat and particle fluxes will interact with the first wall, compromising the performance of both the plasma and wall components. These plasma-material interactions involve diverse plasma and materials physics, and further, are multi-scale in nature. To address this complex system, we have developed and validated an integrated computational model for interpretation and prediction of plasma-material interactions in plasma-facing materials. The model includes descriptions for the edge plasma, near-surface sheath, impurity erosion and redeposition, particle recycling, surface morphology and sub surface evolution. The model has already been used to interpret experiments in current devices, such as WEST, to predict the evolution of the ITER divertor under a range of operational conditions, as well as to explore the impact of plasma impurities in fuel recycling. Here, we present the latest applications of our model, including increased fidelity predictions for the evolution of the ITER divertor.