학술논문
First measurement of the low-energy direct capture in 20Ne(p, {\gamma})21Na and improved energy and strength of the Ecm = 368 keV resonance
Document Type
Working Paper
Author
Masha, E.; Barbieri, L.; Skowronski, J.; Aliotta, M.; Ananna, C.; Barile, F.; Bemmerer, D.; Best, A.; Boeltzig, A.; Broggini, C.; Bruno, C. G.; Caciolli, A.; Campostrini, M.; Casaburo, F.; Cavanna, F.; Ciani, G. F.; Ciapponi, A.; Colombetti, P.; Compagnucci, A.; Corvisiero, P.; Csedreki, L.; Davinson, T.; Depalo, R.; Di Leva, A.; Elekes, Z.; Ferraro, F.; Fiore, E. M.; Formicola, A.; Fülöp, Zs.; Gervino, G.; Guglielmetti, A.; Gustavino, C.; Gyürky, Gy.; Imbriani, G.; José, J.; Junker, M.; Lugaro, M.; Manoj, P.; Marigo, P.; Menegazzo, R.; Paticchio, V.; Piatti, D.; Prati, P.; Rapagnani, D.; Rigato, V.; Robb, D.; Schiavulli, L.; Sidhu, R. S.; Straniero, O.; Szücs, T.; Zavatarelli, S.
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Subject
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Abstract
The $\mathrm{^{20}Ne(p, \gamma)^{21}Na}$ 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 $E\rm_{cm} = 352$~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 $\gamma$ rays from the reaction were detected with two high-purity germanium detectors. We obtain a resonance strength $\omega \gamma~=~(0.112 \pm 0.002_{\rm stat}~\pm~0.005_{\rm sys})$~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 $T \geq 0.1$~GK. Initial astrophysical implications are presented.
Comment: 8 pages, 4 figures, accepted to PRC (letter)
Comment: 8 pages, 4 figures, accepted to PRC (letter)