2023/11/07 by Masha, E., Barbieri, L., Skowronski, J. +48 · 2 citations
#FOS: Physical sciences #Nuclear Experiment (nucl-ex) #Solar and Stellar Astrophysics (astro-ph.SR)
paper · doi:10.48550/arxiv.2311.04089
The \mathrm20Ne(p, γ)21Na reaction is the slowest in the NeNa cycle and directly affects the abundances of the Ne and Na isotopes in a variety of astrophysical sites. Here we report the measurement of its direct capture contribution, for the first time below E\rmcm = 352~keV, and of the contribution from the E\rm cm = 368~keV resonance, which dominates the reaction rate at T=0.03-1.00~GK. The experiment was performed deep underground at the Laboratory for Underground Nuclear Astrophysics, using a high-intensity proton beam and a windowless neon gas target. Prompt γ rays from the reaction were detected with two high-purity germanium detectors. We obtain a resonance strength ωγ~=~(0.112 ± 0.002\rm stat~±~0.005\rm sys)~meV, with an uncertainty a factor of 3 smaller than previous values. Our revised reaction rate is 20% lower than previously adopted at T < 0.1~GK and agrees with previous estimates at temperatures T ≥ 0.1~GK. Initial astrophysical implications are presented.