An interference effect in the channel radiative neutron capture process

Abstract

This study shows that the small thermal neutron radiative capture cross sections in 12C and neighbouring nuclides are the result of destructive interference between the potential scattering wave and the resonance scattering wave near the nuclear surface, resulting in a drastic cancellation in the radial integral. The behaviour of the scattering wave function is examined, and the general condition for the occurrence of such cancellation is discussed. The expression for the channel radiative capture cross section which has been derived has the same structure as the Lane-Lynn formula but is expressed in terms of different parameters. In addition, this investigation shows that if the optical model well depth is adjusted so that the binding energy of the p 1 2 orbit in 12C is kept at the experimental value, then the calculated results for the potential and channel radiative neutron capture cross sections are insensitive to the value of the nuclear radius.