STUDY OF THE O-16(O-16,C-12)NE-20 REACTION-MECHANISM BY POLARIZATION MEASUREMENTS

The 16O(16O, 12C)20Ne reaction has been studied at beam energies of 68 and 90 MeV. At these energies, this reaction is selective for populating high-spin states well known to have a large overlap with α + 16O. The angular distributions have been analyzed with an EFR-DWBA code. Good fits are obtained and the resulting relative α-particle spectroscopic factors for the 20Ne states are in good agreement with shell-model predictions, and with other results from different α-transfer reactions. The polarization of 20Ne has been measured by angular correlations between 12C and 16O (product of the 20Ne decay). As expected from a semiclassical view of the transfer, a strong 20Ne polarization, on an axis perpendicular to the reaction plane, has been found. This polarization remains constant on a wide span of 12C angles. Different nuclear reaction models have been tested. With selected potentials, the DWBA predicts a strong polarization in this case of a heavy-ion transfer, but not as strong as the one observed in the experiment. Some possible reasons for this difference are indicated. © 1979.