Modeling the Radial Profile of Tungsten Ions in the WEST tokamak with Local Transport Models and Atomic Interactions Between Charge States

Modeling fusion plasma in a tungsten environment is challenging due to the complex interplay between multiple ion species, especially for tungsten, whose charge state varies with electron temperature. This work presents a global modeling of tungsten transport based on local neoclassical (FACIT) and turbulent (GX) transport simulations, integrating all tungsten charge states. The global coupling is performed through the continuity equation for each tungsten ion and via ionization/recombination as described by ADAS. We also address the turbulent transport of multiple tungsten ions using GX simulations and quasi-linear analysis. This capability is applied to study tungsten accumulation near the axis of the WEST tokamak, with potential comparison to multi-energy soft X-ray diagnostic measurements. Another application explores X-point radiator (XPR) plasmas, investigating nitrogen-tungsten ion interactions and aligning with our effort to validate gyrokinetic modeling of tungsten in the presence of low-Z impurities in WEST [1]. Finally, we will discuss the complementarity of this local approach with XGC global modeling of tungsten transport [2].