Behavior of the reemitted slow positron on hydrogen-adsorbed Ni (1 1 1) surface

We have analyzed the Doppler broadening spectra of the positron annihilation and reemitted slow positrons from hydrogen-adsorbed Ni (1 1 1) surface on different adsorbing conditions. It is shown that the escaping of reemitted slow positrons and ortho-positroniums from hydrogen-lightly adsorbed Ni (1 1 1) is more than that of hydrogen-saturatedly adsorbed Ni (1 1 1).