Reflection of hydrogen from stainless steel and Nb

Polycrystalline targets of stainless steel and Nb have been bombarded at normal incidence by protons and deuterons with energies between 1.0 and 15 keV. The energy distributions of neutral, positive, and negative particles backscattered at 135° have been measured. For bombardment energies above 2.5 keV the spectra of all three components of the backscattered particles and hence their sum show a maximum at low energies. By integrating the spectra absolute particle and energy reflection coefficients were determined. For stainless steel they agree with theoretical expectations while for Nb they are considerably lower.