In this paper we present numerical calculations for the process of bound-free electron-positron pair production following photon impact on bare nuclei. The calculations are based on exact Coulomb waves. We include total as well as differential cross sections for production of both K and L electrons for a wide range of photon energies and nuclear charge numbers. Significant deviations from lowest-order Born theory appear for moderate and high charge numbers in both the total cross section and, most dramatically, in the angular distributions of the emitted positrons. Our results for total K-shell cross sections for photon impact as well as for ion impact, in the latter case as estimated by the virtual photon method, basically confirm those of Aste et al. [Phys. Rev. A 50, 3980 (1994)]. However, we note that by inclusion of L-electron production, the cross section for the ion-induced process is increased by approximately 20% for heavy elements.

• Received 14 May 1996

DOI:https://doi.org/10.1103/PhysRevA.55.402