Interaction of light ions with plasma-facing materials: Improved experimental accuracy and its impact on sputter yield simulations

Abstract

This work investigates how corrections to fundamental parameters describing ion–solid interaction affect sputtering yield simulations based on the binary collision approximation. We review recent experimental assessments of electronic stopping power and short-range repulsive interatomic potentials for light plasma species (H, D, He) in plasma-facing material candidates (W, Fe, EUROFER97), and compare them to widely used semi-empirical and theoretical models. At low energies, discrepancies of up to 60% relative to SRIM-2013 and up to 210% relative to SRIM-1997 are identified for the specific energy loss, highlighting the need for improved input parameters. We assess the sensitivity of sputtering yields to these corrections using SDTrimSP simulations, and compare the results to new experimental sputter yield data obtained for re-deposited thin W, Fe, and EUROFER97 films on a high-sensitivity quartz crystal microbalance. Incorporating derived stopping powers and interatomic potentials into the simulation significantly reduces the discrepancies between experimental and simulated sputtering yields. Remaining uncertainties and model limitations, such as crystal structure effects and ion implantation, are discussed.