Elastic and Inelastic Scattering of 31.1-MeV Protons by Carbon-12

The angular distributions of 31.1-MeV protons scattered by the ground state and the 4.4-, 7.7-, 9.6-, 12.7-, 14.0-, 15.1-, and 16.1-MeV excited states have been measured. The differential cross sections for the elastic scattering have been analyzed using the diffuse-surface optical model of the nucleus for a wide range of parameters. This analysis indicates that at this energy the best fit requires a potential characterized by volume, as well as surface, absoprtion. The angular distributions of the inelastically scattered protons are peaked forward and have been compared to predictions of direct interaction theories.