Integrated, multi-physics modeling of erosion, redeposition and gas retention in the ITER divertor

We present an integrated model designed to capture the multi-physics nature of interactions between the edge plasma and surrounding wall surfaces. This workflow includes SOLPS simulations of the edge plasma in steady-state; the effect of the sheath at shallow magnetic angles, evaluated by hPIC; GITR calculations of transport and redeposition of impurities eroded from the surface; and the response of the wall modeled by coupling F-TRIDYN and Xolotl, which evaluate surface growth and erosion and sub-surface gas dynamics. We benchmark this workflow against PISCES experiments, which measured mass loss, spectroscopy and gas concentration profiles for W substrates exposed to D-He plasmas. Given the positive comparison, we apply the model to predicting impurity migration and redeposition, surface growth and erosion, and gas recycling in the ITER divertor, under conditions expected for He and burning-plasma operations.

This material is based upon work supported by the U. S. DOE, Office of Science, Office of Fusion Energy Sciences and Office of Advanced Scientific Computing Research through the SciDAC project on Plasma-Surface Interactions. This research used resources of the NERSC, a U.S. DOE Office of Science User Facility operated under Contract No. DE-AC02-05CH11231.