The eigenchannel R-matrix method is used to describe a set of two-electron escape processes. This method is applied to calculate both bound state excitation and ionization cross sections for a simplified model of electron-hydrogen scattering and electron-${\mathrm{He}}^{+}$ scattering, in which only zero angular momentum states are considered. The results shown are calculated for incident electron energies ranging from 13.6–50 eV for electron-hydrogen scattering and from 54.4–200 eV for electron-${\mathrm{He}}^{+}$ scattering. A frame transformation technique is introduced to improve the stability of calculated ionization cross sections. The R-matrix results are compared with cross sections obtained from a convergent close-coupling approach and with other results.

• Received 10 April 1995

DOI:https://doi.org/10.1103/PhysRevA.52.1334