THE STRUCTURE AND REACTIONS OF NEUTRON-RICH NUCLEI

This article aims at reviewing the present status of the understanding of the structure and reactions of neutron-rich nuclei. The properties of the low-lying soft giant dipole resonance in Li-11 are discussed within several models proposed for the purpose. The existence of this collective mode in heavier neutron-rich nuclei is considered. The question of the separation energy of a single neutron and a dineutron is discussed. The nuclear and Coulomb dissociation cross sections for Li-11 on several targets are calculated and compared to the available data. The question of the neutron halo is then considered in detail. The elastic scattering of Li-11 and other unstable nuclei on several stable targets (p, Pb-208, etc.) is discussed in detail. The signature of the halo on the elastic cross section sigma(el) is then assessed. Proposed experiments are discussed in the light of the theoretical prediction. The effect of the break-up channel (2n + Li-9 in Li-11) on sigma(el) is thoroughly analysed. The total reaction cross section and total nuclear reaction cross section is also calculated using the microscopic t(rho1rho2)-Glauber theory. The production of pi's is considered and model calculations are performed. The low-energy fusion of neutron-rich nuclei with heavy targets is analysed. Having in mind the possibility that the low-lying soft giant-dipole resonance may greatly aid the system to fuse even at sub-barrier energies, the viability of produing superheavy elements are studied. The astrophysical implications of exotic nuclei are assessed and discussed. Finally, the momentum and angular distributions of fragments from Li-11 breakup are calculated and compared to the available data.