Angular-Correlation Studies of the ReactionsO16(He3, αγ)O15,C12(He3, pγ)N14, andC12(d, pγ)C13

Abstract
Mixing ratios of some gamma-ray transitions in O15, N14, and C13 have been studied by particle-gamma angular-correlation measurements for the reactions O16(He3, αγ)O15, C12(He3, pγ)N14, and C12(d, pγ)C13. The outgoing particles were detected close to 180° in an annular counter. For the He3 beam energies available it was possible to study all the bound states of N14, but only the 5.18-5.24-MeV doublet (unresolved) and the 6.16-MeV level of O15 could be studied in detail. An attempt was also made to obtain the mixing ratio of the ground-state transition from the 3.85-MeV level of C13. Spin assignments were verified wherever possible and the spin of the 5 24-MeV level of O15 has been established as 52 Gamma-ray branching ratios were determined for the levels of N14 and were generally in agreement with previous work. Strong evidence was found for a weak transition between the 5.10-MeV and 3.95-MeV states of N14, but the previously reported transition between 7.03 and 3.95-MeV states was not observed. Correlations for the C12(He3, pγ)N14 reaction were measured at four different energies, since they can vary with energy. It was found from the correlations that the N14 levels were strongly populated in the m=0 substate. This has been interpreted as due to a direct interaction, possibly heavy-particle stripping.