Electron impact single ionization of helium with large energy transfer

We report triply differential cross section (TDCS) for electron impact single ionization of helium at the incident energy of 729.6 eV for a variety of scattering angles and ejection energies. The calculations are based on two different methods, namely, the Glauber approximation (GA) and the 3C approximation, also called the BBK method. In the GA the effects of post collision interaction have been taken into account by a classical method, whereas the BBK method has been studied with and without exchange. A comparison is made of the present TDCS with the results of other calculations and the experimental data from two different laboratories. For large energy transfer we find a significant contribution from the exchange effect. Both the GA-PCI and the BBK methods show some shifts in the position of binary maxima which are in reasonably good agreement with experiment.