Schedule by Session

The 23Na(a,p)Mg reaction has been identified as having a significant impact on the nucleosynthesis of elements, such as 23Na and 26Al, in massive stars, and of light isotopes in type-Ia supernovae.
We will present new experimental results, as well as a combined reaction rate based on all available data, and an assessment of its astrophysical impact on massive stars and type-Ia supernovae.

Until 2014 this reaction was only measured in experiments which suffered from normalisation issues. Accordingly, reaction rate compilations such as REACLIB preferred Hauser-Feshbach statistical reaction rates, whose uncertainty may be greater than a factor of 3 for this reaction.
Since 2014 there have been several measurements of the reaction utilising various new techniques to avoid the earlier experimental issues. All of the experiments have found results consistent with one another, as well as with Hauser-Feshbach predictions in the energy range E = 1.7 - 3.0 MeV.

We have directly measured new angular distributions using the setup in reference and have corrected the data in references based on these angular distributions, in order to reduce their systematic uncertainty. From these corrected data we calculate a new, combined, experimental reaction rate. We have then implemented this reaction rate into astrophysical models of massive stars and type-Ia supernovae, using nuclear post-processing codes to identify its impact on the nucleosynthesis of key isotopes in the mass range 20-30, and from these provide improved constraints on abundances. The impact of these results on galactic 23Na and 26Al production will be discussed.