Reactions with the double-Borromean nucleus 8He

Abstract

Differential cross sections for elastic-scattering and neutron-transfer reactions along with cross sections for fusion in the He-8+Cu-65 system are reported at energies above the Coulomb barrier (E-lab = 19.9 and 30.6 MeV). The present work demonstrates the feasibility of using inclusive measurements of characteristic in-beam gamma rays with low-intensity (similar to 10(5) pps) radioactive ion beams to obtain the residue cross sections for fusion and neutron transfer. Exclusive measurements of gamma rays in coincidence with light charged particles have been used to further characterize the direct reactions induced by this double-Borromean nucleus. Coupled reaction channels calculations are used to illustrate the important role played by the transfer channels and to help in understanding the influence of the structure of He-8 on the reaction mechanism.