Direct Interaction in Neutron Inelastic Scattering

Abstract

The direct interaction contribution to the cross section for the inelastic scattering of neutrons leading to the excitation of a single particle of the target nucleus is derived by using the method of distorted waves. The interaction potential between the incident neutron and target nucleon is taken to be a three-dimensional delta function, and the incident and emergent neutrons are assumed to move in the complex potential of the cloudy crystal ball model. The wave functions for the target nucleons are described in terms of the single-particle model.The theory is applied to the excitation of the first level in ${\mathrm{C}}^{12}$. The angular distribution of the emergent neutrons is forward-peaked. The magnitude of the cross section is small, however, and the effect will most easily be observed at neutron energies which lie between the levels of the compund nucleus.