Phenomenon of the diffraction rise of cross sections in the forward angular hemisphere as an effect of nuclear and cluster interference

Abstract

Angular distributions of differential cross sections for scattering of alpha-particles on 24Mg nuclei are described as scattering on a black absorbing nucleus and its alpha-cluster components using first-order Bessel functions. The dependence of the interaction radius of alpha-clusters in a nucleus on the energy of incident particles is found. The radius varies because scattering at low energies can occur upon the correlated motion of two or three alpha-clusters. Scattering at average energies occurs mainly on separated alpha-cluster structures. As the energy increases, the contribution from the alpha-particle mode falls while the contribution from the modes of scattering on nucleons rises; this can manifest itself as growth of the interaction radius due to the interference between the alpha-cluster mode and those of smaller cluster structures and nucleons. A contribution to the nonuniform rise of angular distributions of differential cross sections is thus also possible due to these effects.