Dynamical deformation of nuclei in deep-inelastic collisions: A gamma coincidence study of 130Te + 275 MeV 64Ni and 208Pb + 345 MeV 58Ni heavy ion reactions

Abstract

Products of 130Te + 275 MeV 64Ni and 208Pb + 345 MeV 58Ni collisions at energies slightly above the Coulomb barrier have been studied in two gamma spectroscopy thick target experiments. The product yield distributions have been established from the γ – γ coincidence analysis supplemented by target radioactivity measurements. Neutron evaporation from excited primary products has been estimated to determine the pre-emission maps of fragments. The transfer of protons and neutrons between the colliding ions is discussed in terms of the N / Z ratio equilibration. The discussion of experimental N / Z values compared with expectations based on potential energy minimizations leads to conclusion that the involved nuclei are dynamically deformed during the crucial interaction time. These results are discussed in connection with the earlier published study of the 208Pb + 350 MeV 64Ni system [1]. The present and perspective use of deep-inelastic reactions for spectroscopic studies of exotic neutron-rich nuclei in experiments with stable and radioactive beams is outlined.