Fusion cross sections for light systems

A systematic study of heavy-ion fusion cross sections for light systems for which A/sub T/ + A/sub P/ less than or equal to 40 and for bombarding energies up to about 18 MeV/A is in progress at ORNL. A detailed study of the fusion of 16O + 10B and 14N + 12C revealed that, even at energies up to 18 MeV/A, the evaporation- residue (ER) energy spectra, angular distributions, and total yields are consistent with the equilibrium decay of the compound nucleus. Also, for these two systems, the fusion cross sections appear to be dominated by entrance-channel effects of a microscopic nature. In addition, an absolute angular momentum limit has been found at J/sub c/ = 27h-bar. To achieve a better understanding of these effects, further measurements of the 14N + 12C system have been carried out, as well as comparisons with the 10B + 16O system. To extend the systematic study, other systems have been measured, and data are presented for the 14N + 10B, 17O + 10B, 20Ne + 20Ne, and 20Ne + 16O systems covering a range of bombarding energies from 2 MeV/A to about 13 MeV/A