We derive local microscopic optical potentials U systematically for polarized proton scattering at 65 MeV using the local-potential version of the Melbourne g-matrix folding model. As target nuclei, we take 6 He and neutron-rich Ne isotopes in addition to stable nuclei of mass number A = 4-208 in order to clarify mass-number and isotope dependence of U . The local potentials reproduce the experimental data systematically and have geometries similar to the phenomenological optical potentials for stable targets. The target density is broadened by the weak-binding nature and/or deformation of unstable nuclei. For the real spin-orbit part of U the density broadening weakens the strength and enlarges the radius, whereas for the central part it enlarges both of the strength and the radius. The density-broadening effect is conspicuous for halo nuclei such as 6 He and 31 Ne. Similar discussions are made briefly for proton scattering at 200 MeV. We briefly investigate how the isovector and the non spherical components of U affect proton scattering.

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We present a reliable double-folding (DF) model for 4 He-nucleus scattering, using the Melbourne g-matrix nucleon-nucleon interaction that explains nucleon-nucleus scattering with no adjustable parameter. In the DF model, only the target density is taken as the local density in the Melbourne g-matrix. For 4 He elastic scattering from 58 Ni and 208 Pb targets in a wide range of incident energies from 20 MeV/nucleon to 200 MeV/nucleon, the DF model with the target-density approximation (TDA) yields much better agreement with the experimental data than the usual DF model with the frozen-density approximation in which the sum of projectile and target densities is taken as the local density. We also discuss the relation between the DF model with the TDA and the conventional folding model in which the nucleon-nucleus potential is folded with the 4 He density.

We propose a practical folding model to describe 3 He elastic scattering. In the model, 3 He optical potentials are constructed by making the folding procedure twice. First the nucleon-target potential is evaluated by folding the Melbourne g-matrix with the target density and localizing the nonlocal folding potential with the Brieva-Rook method, and second the resulting local nucleon-target potential is folded with the 3 He density. This double single-folding model well describes 3 He elastic scattering from 58 Ni and 208 Pb targets in a wide incident-energy range from 30 MeV/nucleon to 150 MeV/nucleon with no adjustable parameter. Spin-orbit force effects on differential cross sections are found to be appreciable only at higher incident energies such as 150 MeV/nucleon. Three-nucleon breakup effects of 3 He are investigated with the continuum discretized coupled-channels method and are found to be appreciable only at lower incident energies around 40 MeV/nucleon. Effects of knock-on exchange processes are also analyzed.

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