Geant4 and Theoretical Pair Production Cross Sections for 1 MeV- 100 GeV photons in Aluminum

Tabulated data of pair and triplet production cross sections published in the literature [1] were compared to the Geant4 implementation [6] of the same processes for 1 MeV to 100 GeV photons in an aluminum target. The results demonstrated that the Geant4 cross section consistently follows the the theoretical values. 2 Theoretical Description Theoretical description of the pair production cross sections are discussed in several papers [1, 2, 3, 4, 5]. The tabulated data results that were used are calculated by H. Hubbell, H. A. Gimm, I. Overbo in JPCRD 9(4) pp. 1023-1147 (1980). The pair production cross sections are based on Bethe-Heithler bremsstrahlung cross sections since these two physical processes have similarities. If we take the pair production diagram and reverse incoming photon and outgoing positron in time, we get the bremsstrahlung diagram. The authors used two energy regimes for the coherent pair production