Speaker
Description
Tungsten sputtering, redeposition, and transport in the divertor region are key processes governing impurity migration and contamination of the plasma core in fusion devices. Predictive modelling of these processes requires a coupled description of edge-plasma transport, sheath acceleration, plasma–surface interaction, sputtering, ionization, recombination, and impurity redeposition. In this work, we present a one-dimensional integrated workflow for modelling tungsten impurity production and transport in the divertor. The framework couples Hermes-3 for edge-plasma transport with a kinetic/analytical sheath model, a Monte Carlo impurity ion model, and a Direct Simulation Monte Carlo model for neutral tungsten atoms. Tungsten sputtering yields are calculated using a Monte Carlo ion tracer together with the Eckstein formula. Ionisation and recombination processes are included for tungsten charge states from neutral tungsten to $\text{W}^{20+}$. The model also supports multi-species incident ion populations contributing to tungsten sputtering.
The developed workflow provides self-consistent estimates of tungsten redeposition rates, sputtering yields, and charge-state-resolved tungsten impurity distributions. In addition, the one-dimensional model can supply sputtering and redeposition data for two-dimensional impurity transport simulations. Development of a fully self-consistent two-dimensional model is currently underway.