The 22 Ne( α,n) 25 Mg reaction - state of the art, astrophysics, and perspectives

Best, Andreas; Adsley, Philip; Amberger, Ryan; Battino, Umberto; Chillery, Thomas; La Cognata, Marco; deBoer, Richard James; Mercogliano, Daniela; Ota, Shuya; Rapagnani, David; Sidhu, Ragandeep Singh; Spartà, Roberta; Tumino, Aurora; Wiescher, Michael

Abstract

One of the most important stellar neutron sources is the 22Ne(α, n)25Mg reaction, which gets activated both during the helium intershell burning in asymptotic giant branch stars and in core helium and shell carbon burning in massive stars. The 22Ne(α, n)25Mg reaction serves as the main neutron producer for the weak s-process and provides a short but strong neutron exposure during the helium flash phase of the main s-process, significantly affecting the abundances at the s-process branch points. The cross section needs to be known at very low energies, as close as possible to the neutron threshold at Eα= 562 keV (Q = −478 keV), but both direct and indirect measurements have turned out to be very challenging, leading to significant uncertainties. Here we discuss the current status of the reaction, including recent and upcoming measurements, and provide a discussion on the astrophysical implications as well as an outlook into the near future.

Citation

Best, A., Adsley, P., Amberger, R., Battino, U., Chillery, T., La Cognata, M., deBoer, R. J., Mercogliano, D., Ota, S., Rapagnani, D., Sidhu, R. S., Spartà, R., Tumino, A., & Wiescher, M. (2025). The 22 Ne( α,n) 25 Mg reaction - state of the art, astrophysics, and perspectives. European Physical Journal A: Hadrons and Nuclei, 61(5), Article 99. https://doi.org/10.1140/epja/s10050-025-01572-y

• Journal Article Type: Article
• Acceptance Date: Apr 14, 2025
• Online Publication Date: May 10, 2025
• Publication Date: May 10, 2025
• Deposit Date: May 19, 2025
• Publicly Available Date: May 19, 2025
• Journal: The European Physical Journal A
• Print ISSN: 1434-6001
• Electronic ISSN: 1434-601X
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 61
• Issue: 5
• Article Number: 99
• DOI: https://doi.org/10.1140/epja/s10050-025-01572-y
• Public URL: https://keele-repository.worktribe.com/output/1238514
• Publisher URL: https://link.springer.com/article/10.1140/epja/s10050-025-01572-y