Pair Production by Photons on Electrons

The cross section for production of electron pairs by unpolarized photons in the field of an electron is calculated. The total cross section is obtained by numerical integration. The contributions to the total cross section from different diagrams (exchange and \ensuremath{\gamma}\ensuremath{-}eterms) are calculated separately, and it is shown that Borsellino's result for the cross section is valid for photon energies above about 8 MeV, the...