(e, 2e) triple-differential cross sections of helium and argon at 64.6 eV

The distorted-wave Born approximation with spin averaged static exchange potential and modified semiclassical exchange potential has been used to calculate the triple-differential cross section of He (1s 2 ) and Ar (3p 6 ) in the coplanar to perpendicular plane geometry. Similar to helium a strong interference minima in the cross section has been observed for the argon atom for all the incident electron angles. The triple-differential cross section in the case of argon at low- and high-scattering angles is in very good agreement with the present experiment. Inclusion of postcollision interaction gives a dip at 45° (characteristic feature of p-orbital targets), which has not been observed exactly at 45° by the experiment and calculations without postcollision interaction. The agreement with experiment in case of helium is quite good, but in the case of argon, some discrepancies are still there.