The 23Na({\alpha},p) 26Mg reaction rate at astrophysically relevant energies

TL;DR

This study measures the 23Na(α,p)26Mg reaction cross sections at astrophysically relevant energies to verify previous estimates, finding no significant deviation from statistical model predictions, thus supporting existing reaction rate recommendations.

Contribution

The paper provides new differential cross section measurements for the 23Na(α,p)26Mg reaction, confirming the validity of current statistical model-based reaction rates at relevant energies.

Findings

Measured cross sections align with statistical model predictions.

Confirmed previous reaction rate recommendations without increase.

Implications for 26Al production in massive stars.

Abstract

The production of 26 Al in massive stars is sensitive to the 23 Na(a,p) 26 Mg cross section. Recent experimental data suggest the currently recommended cross sections are underestimated by a factor of 40. We present here differential cross sections for the 23 Na(a,p) 26 Mg reaction measured in the energy range E c.m. = 1.7 - 2.5 MeV. Concurrent measurements of Rutherford scattering provide absolute normalisations which are independent of variations in target properties. Angular distributions were measured for both p 0 and p 1 permitting the determination of total cross sections. The results show no significant deviation from the statistical model calculations upon which the recommended rates are based. We therefore retain the previous recommendation without the increase in cross section and resulting stellar reaction rates of a factor of 40, impacting on the 26 Al yield from massive stars by more than a factor of three.