Electronic energy loss of H, D and He in Au below 20 keV

Energy spectra of H, D and He ions transmitted through polycrystalline Au foils have been measured for several entrance and exit angles in the energy range below 20 keV. For some cases also the transmitted neutrals have been energy-analyzed. The maximum in the energy distribution is, however, at the same position for the ions. The values for the stopping power constant for H and D are larger than the LSS value by a factor of 2 for energies above about 10 keV, but are decreasing at lower energies, i.e. the stopping power is no longer proportional to the velocity. For He the stopping power constant is 1.5 times larger than the LSS value. (orig.)