Nuclear reaction cross sections of 16O + 16O obtained by γ-ray detection

Abstract

The partial production cross sections for reaction residues produced by the fusion of 16O with 16O have been measured at E c. m = 9–30 MeV by detecting the characteristic γ-rays with a Ge(Li) detector. The dominant products are 24Mg and 27A1 corresponding to 2α and αp emission from the compound nucleus, respectively. The total γ-producing cross sections σ R were also derived by summing the partial cross sections after correction for the observed (average) γ-ray angular distributions. The trend in the total cross sections is very similar to the trends derived from an optical model or a statistical-evaporation model calculation. The partial production cross sections were compared with other experimental results at 11.9 MeV and 30 MeV and with the results of the statistical-model calculation. It is concluded that the treatment of angular momentum in the calculation is inadequate for describing the partial cross sections. Structure in the partial and total cross section excitation functions is observed with minima occurring at E c.m. = 27, 24, 20, 17.5, and possibly 15 MeV. Some of this structure is well established by the statistical accuracy of the data and most, but perhaps not all of it, is correlated in the various channels. This structure is compared with that observed in another experiment and some of its implications are discussed.