Z2 dependence of peak energies of loss electrons backscattered from metal targets by He+ impact.

Abstract

Energy distributions of secondary electrons emitted backward from Au, Ag, Cu, Al, and Be targets were measured in the energy range from 100 to 1000 eV for impacts of ${\mathrm{He}}^{+}$ and ${\mathrm{He}}^{2+}$ ions with velocities corresponding to 1.1 MeV/amu. Energies, ${E}_{p}$, at which electron loss peaks for ${\mathrm{He}}^{+}$ impact take maximum values are found to show pronounced target dependence. The order of ${E}_{p}$ for these targets is AugCugAggAlgBe This dependence of ${E}_{p}$ is explained in terms of energy loss of loss electrons in their transportation to the surface.