Multi-Nucleon Transfer Reactions As A Tool For Spectroscopy Of Heavy Nuclei

Multi-nucleon transfer reactions have been shown to be an important tool for high-spin spectroscopic studies of Rn, Ra and Th nuclei with N similar or equal to 134. These nuclei have been populated using the heavy-ion collisions of Fe-56 + Th-232, Kr-86 + Th-232 and Xe-136 + Th-232 at beam energies 15-20% above the Coulomb barrier. Excited states with spins as high as 28h have been observed using the latter reaction. Yield distributions of binary-reaction products stopped in thick targets have been derived from the analysis of gamma-gamma and gamma-gamma-gamma coincidence events. These yields indicate that there is significant fission of the target-like reaction products. Intensities deduced for products resulting from neutron transfer or proton transfer appear to be Q-value dependent, while processes involving transfers of several protons and neutrons are governed by mass and charge equilibration.