Differential cross sections for ionization of argon by 0.3-2-MeVHe2+andHe+ions

Abstract

The energy and angular distributions of electrons ejected from argon are reported for ionization by ${\mathrm{He}}^{+}$ and ${\mathrm{He}}^{2+}$ ions in the energy range 0.3-2.0 MeV. Absolute cross sections derived from these measurements illustrate the effect of screening and the contribution to the electron spectra of the projectile electron. Comparison of the cross sections to previous data for equivalent-velocity proton impact provides an indication of the region of applicability of $Z^2$ scaling for differential ionization cross sections. The significance of continuum charge transfer and projectile stripping are discussed with regard to their contribution to the ionization process.