Protons Ejected from Nickel by 17·5 MeV Bremsstrahlung

Abstract

It has been shown that the energy and angular distribution of photoprotons from middle-weight nuclei (Z about 30) can be almost entirely accounted for by the statistical theory of nuclear reactions (Byerly and Stephens 1951; Toms and Stephens 1954). The evidence indicates that the direct photo effect contributes only a small amount to the emitted photoproton spectrum. However, the statistical theory does not explain, among other things, why the photoproton yield at 23 MeV from copper and nickel should be about three times that from cobalt (Mann and Halpern 1951).