Resonance levels in 28Si from 27Al+p reactions

Abstract

By measuring the proton elastic scattering from 27A1 with surface barrier detectors, 18 resonance levels in 28Si were observed in the energy range E p = 1.1–1.8 MeV. For all resonances, the proton orbital momenta were determined, and for 12 resonances unique spin assignments were made on the basis of these and previous (p, γ) and (p, α) measurements. Partial proton widths are given for all resonances. The yield of inelastically scattered protons from 27Al and of the emitted α-particles to the first excited state in 24Mg was also observed. Resonance strengths were determined relative to the known strength of the 1184 keV resonance in the 27Al(p,γ) 28Si reaction. Seven resonances can be classified as probable analogues of the 3.46, 3.59, 3.67, 3.88, 3.93 and 4.03 MeV states in 28A1. For all T = 1 resonances spectroscopic factors were deduced.