First measurement of the low-energy direct capture in 20Ne(p ,γ )21Na and improved energy and strength of the Ec.m.=368 keV resonance
Abstract
The 20Ne(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 Ec .m .=352 keV, and of the contribution from the Ec .m .=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 ω γ =(0.112 ±0 .002stat±0 .005sys)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.
- Publication:
-
Physical Review C
- Pub Date:
- November 2023
- DOI:
- 10.1103/PhysRevC.108.L052801
- arXiv:
- arXiv:2311.04089
- Bibcode:
- 2023PhRvC.108e2801M
- Keywords:
-
- Nuclear Experiment;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 8 pages, 4 figures, accepted to PRC (letter)