The (16O, 12C) cross sections have been measured for lab angles, θ ≧ 4° on targets of 24Mg and 28Si at lab beam energies ranging from 36 to 53 MeV. Angular distributions have been extracted for transitions to the ground states and first excited states at all beam energies studied. Angular distributions for higher excited states (up to ≈ 8 MeV) have been extracted for 24Mg(16O, 12C)28Si at 48 MeV and for 28Si(16O, 12C)32S at 42 MeV. An analysis has been performed with the full finite range DWBA code LOLA. Although the angular distribution shapes can be reproduced with reasonable DWBA calculations and the resulting relative spectroscopic factor products are energy independent and agree well with (6Li, d) spectro-spectroscopic factors, there are significant difficulties encountered in applying the DWBA treatment. Absolute spectroscopic factors decrease by a factor of ≈ 5 as bombardment energy is increased through the ≈20 MeV range of this investigation and the shape of the DWBA predicted angular distribution is very sensitive to the choice of optical model parameters at bombarding energies near the Coulomb barrier. Interestingly a two parameter Frahn and Venter model calculation reproduces the l = 0 angular distributions for both targets with an energy variation of the absolute normalization factor which is significantly smaller than that resulting from the DWBA analysis.
- Nuclear Reactions
ASJC Scopus subject areas
- Nuclear and High Energy Physics