Some aspects of the secondary ion emission from metals

Two classes of experiments on the determination of an ionization mechanism of sputtered atoms have been performed. Threshold energy of secondary ion emission when bombarding a number of metals with Cs+ ions have been investigated in the first class. The obtained threshold energies have been compared with corresponding thresholds of cathode sputtering. In the second class of the experiments investigated was the change in energy spectra of knocked-out ions of Nb+ and Mo+ when changing Hg+ ion energy bombarding the corresponding polycrystalline targets. Incident ion energy varied in the range from 250 to 2000 eV. It follows from the analysis of the results obtained that the ion production during the sputtering is determined with the electron-exchange mechanism of the secondary ion emission