Anisotropic excitation of hydrogen 2p after grazing ion-surface scattering

We observed the Stokes’ parameters of Lyman-α radiation emitted from hydrogen 2p after interaction of fast H+- and D+-ions at a clean Ni(111)-surface at grazing incidence. The large degree of circular polarization of light and little variation of the Stokes’ parameters with projectile energy compare well with theory describing the capture of electrons into excited states of hydrogen atoms from a free-electron metal surface. © 1988 IOP Publishing Ltd.