High charge effects on electron excitations in metal targets for Ar 12+ impact compared with those for He 2+ impact

Abstract

Energy spectra of secondary electrons (SE) and Auger electrons (AE), LVV-AE for Al, MVV-AE for Cu, and NVV-AE for Au, are measured in the energy range from 20 eV to 120 eV for impacts of He 2+ and Ar 12+ with incident energies corresponding to 1.1 MeV/amu. Ratios of yields for Ar 12+ to those for He 2+ for AE are found to be significantly smaller than the values interpolated from the ratios of yields only relevant to SE. The mechanisms of the reduction of AE yields relative to SE yields for Ar 12+ impact are discussed.