Fr.: production de paires
Formation of an → electron and a → positron in the interaction of high-energy γ-ray photons, having at least 1.02 Mev, with an atomic nucleus (γ → e- + e+). The → rest masses of the electron and positron being 0.51 MeV each, the excess energy will be carried away by these two particles. The pair production is the inverse process to → pair annihilation.