The first direct measurement of 12C(12C,n)23Mg at stellar energies

TL;DR

This study provides the first direct measurement of the 12C(12C,n)23Mg reaction at stellar energies, improving the reaction rate data crucial for understanding nucleosynthesis in stars and supernovae.

Contribution

It introduces a new direct measurement of the 12C(12C,n)23Mg reaction at astrophysical energies and a novel extrapolation method using mirror reaction data.

Findings

Reaction rate determined with well-defined uncertainty

Reveals the reaction's role in Na and Al production in supernovae

Highlights the reaction's impact on gamma-ray emitter 60Fe

Abstract

Neutrons produced by the carbon fusion reaction 12C(12C,n)23Mg play an important role in stellar nucleosynthesis. However, past studies have shown large discrepancies between experimental data and theory, leading to an uncertain cross section extrapolation at astrophysical energies. We present the first direct measurement that extends deep into the astrophysical energy range along with a new and improved extrapolation technique based on experimental data from the mirror reaction 12C(12C,p)23Na. The new reaction rate has been determined with a well-defined uncertainty that exceeds the precision required by astrophysics models. Using our constrained rate, we find that 12C(12C,n)23Mg is crucial to the production of Na and Al in Pop-III Pair Instability Supernovae. It also plays a non-negligible role in the production of weak s-process elements as well as in the production of the important galactic gamma-ray emitter 60Fe.