Measurements and calculations of neutron scattering in the actinide region.

Neutron scattering differential cross sections were measured for $^{232}\mathrm{Th}$, $^{238}\mathrm{U}$, and $^{239}\mathrm{Pu}$ at 14.1 MeV. Optical model calculations were performed using the coupled-channel formalism for deformed nuclei as given by Tamura. Several microscopic and phenomenological optical model potentials were tested for these heavy nuclei: (i) a folding optical model potential using the microscopic nucleon-nucleon effective interaction of Jeukenne, Lejeune, and Mahaux with deformed nuclear density distributions (these calculations are addressed in the text as semimicroscopic optical model potentials), (ii) global phenomenological optical model potentials optimized for the actinide region, and (iii) neutron potentials derived from 35 MeV proton optical potentials using the Lane formalism. The total cross sections calculated from these optical model potentials at 14.1 MeV are also compared with measurements in the literature. The semimicroscopic calculations reproduce reasonably well the measured angular distributions with only two free parameters used to optimize fits to the data. The calculations carried out with optical potentials inferred from proton data give good agreement with the neutron data, an agreement which is similar to that between calculational results using neutron global potentials optimized for this mass region and the measured data.