Study of heavy di-nuclear systems

We investigated di-nuclear system formation with successive nucleon transfer at beam energies at and below the barrier in the superheavy systems 64 28 Ni + 207 82 Pb ( Z p r o j . + Z t a r g e t = 110 ) and 238 92 U + 238 92 U ( Z p r o j . + Z t a r g e t = 184 ). In both collision systems we observed a massive transfer of nucleons correlated with the dissipation of the entire kinetic energy. The results are in accordance with the two-center shell model which assumes the formation of a di-nuclear system as first step to fusion. The experiments have been performed at the velocity filter SHIP (GSI) and at the VAMOS spectrometer (GANIL).