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
Department of Physics, University of Naples Federico II, Via Cintia, Naples, 80126 NA Italy.
Sezione di Napoli, INFN, Via Cintia, Naples, 80126 NA Italy.
Eur Phys J A Hadron Nucl. 2025;61(5):99. doi: 10.1140/epja/s10050-025-01572-y. Epub 2025 May 10.
One of the most important stellar neutron sources is the Ne( )Mg 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 Ne( )Mg reaction serves as the main neutron producer for the weak -process and provides a short but strong neutron exposure during the helium flash phase of the main -process, significantly affecting the abundances at the -process branch points. The cross section needs to be known at very low energies, as close as possible to the neutron threshold at 562 keV ( = -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.
最重要的恒星中子源之一是Ne( )Mg反应，它在渐近巨星分支恒星的氦壳层间燃烧以及大质量恒星的核心氦燃烧和壳层碳燃烧过程中都会被激活。Ne( )Mg反应是弱过程的主要中子产生源，并在主过程的氦闪阶段提供短暂但强烈的中子暴露，显著影响弱过程分支点处的丰度。需要知道非常低能量下的截面，尽可能接近562 keV（= -478 keV）处的中子阈能，但直接测量和间接测量都极具挑战性，导致了很大的不确定性。在这里，我们讨论该反应的当前状况，包括近期和即将进行的测量，并对天体物理学意义进行讨论以及展望不久的将来。
