Improvement of the high-accuracy O-17(p, alpha)N-14 reaction-rate measurement via the Trojan Horse method for application to O-17 nucleosynthesis

0445860 - ÚJF 2016 RIV US eng J - Článek v odborném periodiku
Sergi, M. L. - Spitaleri, C. - La Cognata, M. - Lamia, L. - Pizzone, R. G. - Rapisarda, G. G. - Tang, X. D. - Bucher, B. - Couder, M. - Davies, P. - deBoer, R. - Fang, X. - Lamm, L. - Ma, C. - Notani, M. - O'Brien, S. - Roberson, D. - Tan, W. - Wiescher, M. - Irgaziev, B. - Mukhamedzhanov, A. - Mrázek, Jaromír - Kroha, Václav
Improvement of the high-accuracy O-17(p, alpha)N-14 reaction-rate measurement via the Trojan Horse method for application to O-17 nucleosynthesis.
Physical Review. C. Roč. 91, č. 6 (2015), s. 065803. ISSN 0556-2813
Grant CEP: GA MŠMT LC07050
Institucionální podpora: RVO:61389005
Klíčová slova: thermonuclear reaction rates * cross section * O-17
Kód oboru RIV: BG - Jaderná, atomová a mol. fyzika, urychlovače
Impakt faktor: 3.146, rok: 2015

The O-17(p,a)N-14 and O-17(p,gamma) F-18 reactions are of paramount importance for the nucleosynthesis in a number of stellar sites, including red giants, asymptotic giant branch stars, massive stars, and classical novae. At temperatures typical of the above-mentioned astrophysical scenario, T = 0.01-0.1 GK for RG, AGB, and massive stars and T = 0.1-0.4 GK for a classical nova explosion, the O-17(p, alpha) (14)Nreaction cross section is dominated by two resonances: one at about E-R(cm) = 65 keV above the F-18 proton threshold energy, corresponding to the EX = 5.673 MeV level in F-18, and another one at E-R(cm) = 183 keV (EX = 5.786 MeV). We report on the indirect study of the O-17(p, alpha) N-14 reaction via the Trojan Horse method by applying the approach recently developed for extracting the strength of narrow resonance at ultralow energies. The mean value of the strengths obtained in the two measurements was calculated and compared with the direct data available in literature. This value was used as input parameter for reaction-rate determination and its comparison with the result of the direct measurement is also discussed in the light of the electron screening effect.
Trvalý link: http://hdl.handle.net/11104/0247906