Global Coupled-channels Phenomenological Optical Model Potential for Neutron-Nucleus Scattering From 6Li to 238U

Abstract

The neutron - nucleus scattering process is considered to develop smooth functional forms for the real and imaginary parts of the phenomenological optical potential using the formalism of coupled - channels analysis. We consider intermediate and heavy nuclear targets and investigate the possibility of extending the model to the usually excluded case of light nuclei. Using our model, we simultaneously predict elastic and inelastic angular distributions for neutron scattering from 6Li to 238U for various energies in the range 100 keV < E < 30 MeV for which inelastic angular distributions data are available. We obtain smooth forms for the real and imaginary depths of the volume and surface potential terms as functions of energy, mass number and the asymmetry between the proton and neutron numbers in the target nucleus. The depths of the real and imaginary spin - orbit term, and all the geometry parameters of the potential are fixed. Our predicted elastic and inelastic differential cross sections are in very good agreement with the measured data. The calculated total elastic, total cross sections and the analyzing powers are in a fair overall agreement with the experimental values particularly for the intermediate and heavy nuclei.

Keywords

• optical model potential
• elastic scattering
• inelastic scattering
• coupled channels
• differential cross section