The Levels of 27Al

Coincidences between gamma-rays and scattered protons were taken using ²⁷ Al( p , p ' γ) reaction at a proton energy of 5.7 MeV. Protons were detected by a surface barrier solid state detector at right angles to the beam. Gamma-rays were measured by a 12.7 cm×10.2 cm NaI(Tl) crystal placed at right angles to the beam. From the coincident gamma-ray spectra, gamma-ray branching ratios were calculated for excited levels below 4.504 MeV. Spins of \(\frac{3}{2}\) and \(\frac{9}{2}\) are suggested for the 3.951 and 4.50 MeV level respectively from these results. Rotational model description of the ²⁷ Al nucleus is discussed.