Al-26 + p elastic and inelastic scattering reactions and galactic abundances of Al-26

Galactic Al-26 is the first radioactive nucleus to be positively identified by gamma-ray astronomy with detection of the 1.809 MeV gamma ray associated with its decay. This nucleus is destroyed in astrophysical environments in the Al-26(p,gamma)Si-27 and inelastic Al-26 + p scattering reactions where properties of Si-27 levels determine reaction rates. To investigate these properties, elastic and inelastic Al-26 + p scattering reactions were measured between E-c.m. = 0.5-1.5 MeV at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). A candidate for a new resonance in the Al-26(p,gamma)Si-27 reaction was identified. Upper limits were also set on the strengths of postulated resonances and on the cross section of the inelastic reaction, but there is little effect on current reaction rate calculations.