Modeling of Tungsten Transport in the SAS-VW Divertor with Mixed-Impurity Plasmas*

A new workflow has been developed to model tungsten sourcing and transport in DIII-D that provides a more realistic treatment of multiple impurity species using the SOLPS-ITER and DIVIMP codes. New sputtering source routines are being developed for DIVIMP to directly read in all available impurity data from SOLPS-ITER when calculating the tungsten source. This presentation will demonstrate these new routines to model tungsten transport in the new V-shaped Small-Angle Slot divertor of DIII-D with tungsten-coated plasma-facing components (PFCs), SAS-VW, at various rates of nitrogen seeding. The SAS-VW geometry has been specifically designed to improve the control of neutral particles in the divertor, including to minimize impurity leakage, enabling experiments to address important questions about the sourcing and transport of tungsten in a closed divertor geometry.  These new results will expand upon recent work that predicts a tradeoff between tungsten accumulation and nitrogen seeding and suggests the existence of an optimal seeding rate to minimize overall impurity contamination in the core.