Modelling and interpretation of micrometric dust behaviour in tokamaks

As tokamak devices approach more closely and reliably the technical conditions required for confinement of a deuterium-tritium burning plasma, it becomes clear that optimization of the plasma performance requires better understanding of important physics processes occurring in the scrape-off layer which is actually a "composite" plasma, consisting of multiple ion species and heterogeneous dust with variable charge and mass. A number of questions are addressed by numerical models, concerning the mobilization of dust from the plasma facing components, its migration and redeposition in the tokamak configuration and eventually its destiny of ablation and plasmoid formation. A brief overview of selected problems is presented here, with an assessment of the most interesting results and open questions, especially focused on the tungsten and beryllium dust particles in the tokamak JET-ILW (ITER-like wall). The