Revised decay properties of the key 93-keV resonance in the Mg 25 (p,γ) reaction and its influence on the MgAl cycle in astrophysical environments

Abstract

The γ-decay properties of an excited state in Al26 at 6398.3(8) keV have been reexamined using the B11+O16 fusion-evaporation reaction. This level represents a key 93.1(8)-keV resonance in the Mg25+p system and its relative branching to the Al26 ground state, f0, has been determined to be 0.76±0.03 (stat.) ±0.10 (syst.). This is a significantly higher value than the most recent evaluation and implies a considerable increase in the production of cosmic γ rays from Al26 radioactivity.