Single- and double-charge-exchange cross sections for Ar^q++H₂ (q=6, 7, 8, 9, and 11) collisions from 6 eV to 11 keV

The cross sections for single-electron capture, including transfer ionization, and for double-electron capture, have been measured for Ar^q++H₂ for q=6, 7, 8, 9, and 11 with projectile energies from q eV to q keV. Theoretically, the cross sections for Ar⁶⁺ and Ar⁸⁺ impact were calculated using a molecular-orbital expansion method in the energy region from 240 eV to 80 keV, and are in good agreement with experiment. The single-electron-capture cross sections were found to be more than one order of magnitude larger than those for double capture in both experiment and theory. The single-electron-capture cross sections were also compared to the Langevin cross section, a scaling law developed by Müller and Salzborn [Phys. Lett. 62A, 391 (1977)], and the absorbing sphere model.