Modelling of tungsten re-deposition coefficient

Abstract

We study tungsten prompt re-deposition processes at the divertor plates via kinetic modelling of the JET SOL for different divertor plasma parameters. Our simulations demonstrate that the electric field and not the Lorentz Force is the major contributor to the prompt re-deposition process. The fraction of tungsten ions escaping from the divertor plasma is defined by the number of tungsten atoms ionized outside the magnetic sheath and does not exceed 3% of the ions sputtered from the divertor surface. We derived the corresponding fit function for estimation of the re-deposition coefficient.