Auger Electrons from Argon with Energies 150-210 eV Produced byH+andH2+Impacts

Abstract

Secondary electrons in the energy range 150-210 eV produced by 125-300-keV ${\mathrm{H}}^{+}$ and $\mathrm{H}_{2}^{}{}_{}{}^{+}$ impacts on argon gas are measured as a function of their energy and angle of emission. Discrete line spectra are due to Auger transitions from ${\mathrm{L}}_{2}$ and ${\mathrm{L}}_{3}$ vacancy states as well as satellite transitions from multivacancy states. The widths, energies, and branching ratios of the ${\mathrm{L}}_{2}$ and ${\mathrm{L}}_{3}$ vacancy states are presented. Widths of these states are appreciably greater than those obtained with electron impact excitation. This can be attributed to the recoil velocities of the target atom and to the presence of the proton in the vicinity of the emitting atom. The angular distribution of Auger electrons is found to be nearly isotropic, in marked contrast to electrons in the continum spectrum. The cross sections for the production of ${\mathrm{L}}_{2,3}$ and ${\mathrm{L}}_{3}$ vacancy states are determined as a function of impact energy.