Secondary electron emission due to MeV He ions at glancing incidence angles on clean single crystal surfaces

Abstract

The total secondary electron yields per ion, γ, are measured for MeV He + ions incident on clean (001) surfaces of SnTe and PbSe single crystals. The dependence of γ on the incidence angle of the ions is well fitted by 1/sin θ at larger θ. (θ is the angle of incidence with respect to the surface plane.) However, at θ ~ ψ a an abrupt decrease of γ is observed, where ψ a is the characteristic angle of planer channeling. The decrease is due to the specular reflection of ions at the single crystal surface.