Coulomb Effects in Inner Bremsstrahlen

Abstract

The Coulomb correction to the photon spectrum accompanying beta decay is calculated, treating the Coulomb field as a perturbation. It is shown that for allowed and unique first forbidden transitions, the result differs from that of Knipp-Uhlenbeck-Bloch only by the appearance of an extra factor, related to the Sommerfeld factor in ordinary bremsstrahlen. Analytic formulas are presented for these two selection rules, and a comparison made with recent experiments.