Simulation of polycrystalline beryllium sputtering by H, D, T atoms

Abstract

The results of modeling the sputtering coefficients of polycrystalline beryllium by hydrogen isotopes in the range of collision energies of 8 eV-100 keV and their dependences on the angle of incidence of the beam on the surface are presented. This data is necessary for estimating the sputtering of the first wall in the ITER tokamak made from beryllium. A strong surface shape influence on obtained results is shown. The limiting cases of a flat potential barrier (smooth surface) and a spherical potential barrier (a surface consisting of spikes) are considered. The effect of collision cascades on the sputtering coefficient has been established. The dependences of the average depth of sputtered particle formation on the bombarding particles energy are obtained for various angles of beam incidence on the target. The energy spectra and angular dependences of the ejection of sputtered particles are calculated for different energies of bombarding beam atoms. It is shown that the presence of an attractive well in the potential of an incident particle surface changes the sputtering coefficient dependence on incidence angle at small glancing angles. Keywords: Sputtering coefficients, energy and angular distributions of sputtered particles, interatomic potential, hydrogen isotopes, beryllium.