Hartree-Fock studies of the triple differential cross section for electron-impact ionization of the hydrogen atom

Abstract

We report absolute triple differential cross sections in coplanar ${\ensuremath{\theta}}_{12}=\ensuremath{\pi}$ geometry for the ionization of atomic hydrogen by electron impact at low energies. We used our recently extended multiconfiguration Hartree-Fock method successfully to calculate triple differential cross sections of H for incident energies ${E}_{0}$ of 14.6, 15.6, 17.6, 20, and 25 eV for equal energy sharing of excess energies by the two final state continuum electrons. It has been shown that there is very little difference between the results obtained in the Hartree-Fock and the screening potential approximations implying that in the case of H and ${\ensuremath{\theta}}_{12}=\ensuremath{\pi}$ configuration distortion effects between the two outgoing electrons are small even at low energies. Our results are compared with available absolute and relative experimental data and other existing theoretical calculations and are found to be in very good agreement.