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

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 ofWin divertor regions which are exposed to high fluxes of helium and hydrogen isotope with the energy of below 100 eV, 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 intoWsurface 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.