Energy spectroscopy of positrons reemitted from Ag(100)

Measurements of energy distributions and reemission probabilities of epithermal positrons leaving Ag(100) are presented for incident positron energies E between 50 and 3000 eV. The width of the energy spectra increases as E decreases; about 18% of the positrons are reemitted at low E, decreasing to a negligible fraction for E above 1 keV.