Energy levels in 28Si from the 27Al(p, γ)28Si reaction

Abstract

The gamma-ray spectra from twelve 27Al(p, γ)28Si resonances in the Ep = 500 to 800 keV region were investigated with scintillation spectrometers. Both single and coincidence spectra were measured from which the branchings were obtained in the decay of the resonance levels and of lower levels at 1.783 ± 0.008, 4.623 ± 0.015, 6.28 ± 0.02, 6.88 ± 0.05, 7.37 ± 0.02, 7.42 ± 0.02, 7.93 ± 0.03, 8.32 ± 0.05, 8.41 ± 0.05, 8.59 ± 0.03, 8.92 ± 0.02, 9.31 ± 0.02, 9.38 ± 0.02, 9.49 ± 0.02, 9.76 ± 0.02, and 10.71 ± 0.02 MeV. The levels at 9.31, 9.38, and 10.71 MeV very probably have T = 1 character. They would correspond to the ground-state, the 0.03 MeV and the 1.37 MeV levels in 28Al with Jπ = 3+, 2+, and 1+, respectively.

From yield measurements the resonance strengths ωγ = (2J + 1) ΓpΓγ|Γt were obtained for all resonance levels.