Single and double ionization of H2 by He2+

Abstract

Cross sections for the nondissociative single ionization and double ionization of ${\mathrm{H}}_{2}$ by ${\mathrm{He}}^{2+}$ projectiles in the range of 125--750 keV/amu are reported. The results are compared to impact-parameter calculations and to measurements with ${\mathrm{He}}^{+}$ projectiles. The direct double-collision process is found to be the important contributor to double ionization in this range of energies. The single-ionization cross section, when compared to proton bombardment, does not scale as ${\mathit{Z}}^{2}$.