The 30Si (ρ, γ) 31P reaction for bombarding energies between 1.00 and 1.53 MeV

Abstract

Eighteen resonances have been identified as belonging to the 30Si(, γ)31P reaction for proton bombarding energies between 1.00 and 1.53 MeV. The gamma-ray yield of the corresponding excited states of 31P has been measured, and the principle features of the decay have been determined. Double and/or triple angular correlations of the decay radiation were measured at seventeen of the resonances, resulting in unique spin assignments in all cases. Conclusions on parity have been drawn in some cases from the multipole mixing ratios of the capture radiation or from the reduced proton width. The quadrupole-dipole mixing ratio in the decay of the first excited state has been determined as 0.28 ± 0.02. In an appendix it is proven that the mixing ratio determination in this case is ambiguous if only intensity-direction correlation measurements are made. The unique result given here stems partly from other methods of measurement. A corollary to the theorem mentioned, relating to the first gamma ray in a cascade, is also given.