Study of interaction between low energetic hydrogen and tungsten surface by molecular dynamics simulations

Abstract

Tungsten (W) and tungsten-based materials are being considered to use in the Tokamak as the plasma-facing materials (PFMs) owing to their superior performance. Applicability of W in divertor regions which are exposed to high fluxes of helium and hydrogen isotope with the energy of below 100eV, usually at a magnitude of a few eV, is concerned. In the present study, the interaction between low energetic hydrogen atoms and W surface with various crystallographic orientations as (110), (111), and (112) has been investigated by molecular dynamics (MD) simulations with a modified analytical bond order interatomic potential. Most of the incident hydrogen atoms may penetrate deep into W surface with the depth of 1–8 atomic layers. But most of these hydrogen atoms have been reflected. Some of the retention hydrogen atoms are adsorbed on the outside of W surface. Some energy was deposited in the W surface after the radiation. The particle reflection coefficient of W (110) is the largest one and the energy reflection coefficient of W (111) is the largest one among these calculated index surfaces. The results are potentially important for the analysis of the irradiation damage of tungsten.