Light emission by swift He+ ions after focusing and channeling interactions on a monocrystalline nickel surface

Abstract The light emission from 195 keV He + ions excited in scattering at a (101) Ni surface is used to indicate anisotropy effects of beam steering at monocrystalline surfaces. Experiments and computer simulations give clear evidence of focusing by surface channels and of maximum and minimum critical angles for planar channeling.