A four-body approach to electron-impact single ionization of helium atoms

A four-body approach based on the three-Coulomb distorted wave (3CDW) model is applied to study of the electron-impact single ionization of helium atoms. Triply differential cross sections (TDCS) are calculated for different values of the incident and ejection energies and various amounts of the scattering angles. The ejection angular distribution of the TDCS in general exhibits two peaks, binary and recoil peaks. The obtained results are compared with the available experimental data as well as other theoretical predictions. The comparison shows a good agreement between the present calculations and the measurements. The obtained results are also compatible with other theories. (authors)