The 23Na(alpha,p)26Mg cross section at astrophysically relevant energies
by
Alan Howard(Aarhus University)
→
Europe/Zurich
CERN
CERN
Description
The observation of 26Al in the galactic medium, through decay of its daughter nucleus 26Mg, has provided direct evidence for ongoing nucleosynthesis in the galaxy. While the main sites for 26Al production are still uncertain, the C/Ne convective shell within massive stars is a prime candidate. Large-scale network calculations have been reported which assess the impact of various nuclear reactions on 26Al production. A strong sensitivity to the 23Na(a,p)26Mg reaction rate was found, with the 26Al production changing by a factor of 3 for a factor 10 change in cross section. New experimental data, collected in inverse kinematics, have recently been reported which revise the reaction rate upwards by a factor of ~40 in the energy region of interest, significantly greater than the factor of 10 required for a threefold increase in 26Al production. We report here on a measurement performed at Aarhus University to provide independent verification of the 23Na(a,p)26Mg reaction cross section at astrophysically relevant energies. An array of silicon strip detectors were used to obtain detailed angular distributions for outgoing protons. Concurrent Rutherford scattering data were also collected to eliminate any sensitivity to variations in target thickness or stoichiometry. The results of this work will be presented and other ongoing projects at Aarhus University discussed.
