Production of cold fragments in nucleus–nucleus collisions in the Fermi-energy domain

Abstract

The reaction mechanism of nucleus–nucleus collisions at projectile energies around the Fermi energy is investigated with emphasis on the production of fragmentation-like residues. The results of simulations are compared to experimental mass distributions of elements with Z = 21 – 29 observed in the reactions Kr 86 + Sn 124 , 112 at 25 A MeV . The model of incomplete fusion is modified and a component of excitation energy of the cold fragment dependent on isospin asymmetry is introduced. The modifications in the model of incomplete fusion appear consistent with both overall model framework and available experimental data. A prediction is provided for the production of very neutron-rich nuclei using a secondary beam of Sn 132 where e.g. the reaction Sn 132 + U 238 at 28 A MeV appears as a possible alternative to the use of fragmentation reactions at higher energies.