Dirac analysis of 3He scattering at intermediate and low energy

Abstract

The Dirac optical model is extended to describe the scattering of the ³He particles, which are regarded as spin-half one-body particles. The model is employed for ³He + ¹²C, ³He + ⁵⁸Ni, and ³He + ⁹⁰Zr elastic scattering at 443 MeV. The scalar and vector optical potentials are derived, producing a good description of the experimental differential cross-sections and polarization data. Furthermore, a satisfactory description of the elastic scattering data for the ³He + ⁹⁰Zr over an incident energy range of 29.8–217 MeV is obtained, which confirms the validity of the Dirac optical model at intermediate and low energy. A wine-bottle-shaped potential is observed for the description of ³He + ⁹⁰Zr scattering at incident energies of 43.3 and 72.3 MeV per nucleon; this is analogous to the behavior of potentials describing the scattering of protons and deuterons. Volume integrals of effective central optical potentials for ³He scattering are discussed, and the calculated total cross-sections are compared with the available measured values.