Astrophysical S factor of the N14(p,γ)O15

Abstract

The 14 N(p,γ) 15 O reaction is the slowest reaction of the carbon-nitrogen cycle of hydrogen burning and thus determines its rate. The precise knowledge of its rate is required to correctly model hydrogen burning in asymptotic giant branch stars. In addition, it is a necessary ingredient for a possible solution of the solar abundance problem by using the solar 13 N and 15 O neutrino fluxes as probes of the carbon and nitrogen abundances in the solar core. After the downward revision of its cross section due to a much lower contribution by one particular transition, capture to the ground state in 15 O, the evaluated total uncertainty is still 8%, in part due to an unsatisfactory knowledge of the excitation function over a wide energy range. The present work reports precise S-factor data at twelve energies between 0.357-1.292 MeV for the strongest transition, capture to the 6.79 MeV excited state in 15 O, and at ten energies between 0.479-1.202 MeV for the second strongest transition, capture to the ground state in 15 O. An R-matrix fit is performed to estimate the impact of the new data on astrophysical energies. The recently suggested slight enhancement of the 6.79 MeV transition at low energy could not be confirmed. The present extrapolated zero-energy S-factors are S6.79(0) = 1.24±0.11 keV barn and SGS(0) = 0.19±0.05 keV barn.

Reaction rate of p14N →15Oγ capture to all bound states in potential cluster model

“…8 one can see a good description of value of the second maximum at 990 keV equal to 40 keV·b with an experimental value of 48 keV·b. 50 In interresonance energy range, the calculated S-factor is generally consistent with measurements, 54,56 especially in the second resonance region. Although rate of decrease of the calculated S-factor after the first resonance is not as strong as experimental measurements of well-known works Refs.…”

“…Although rate of decrease of the calculated S-factor after the first resonance is not as strong as experimental measurements of well-known works Refs. [50][51][52]54,56 show.…”

“…Let us first give some experimental values for the S-factor at the capture to the GS of 15 O, which are grouped in Table 14. In one of the most recent studies on behavior of astrophysical S-factor of the proton capture on 14 N, including the capture to the GS, 54 the smallest of all 0.19(5) keV·b is given. From these results, we obtain range of values of 0.08-0.57 keV·b, which gives an average over interval value of 0.33 (25) keV·b.…”

Felsenkeller 5 MV underground accelerator: Towards the Holy Grail of Nuclear Astrophysics 12C(α, γ)16O

“…The Felsenkeller scientific program draws on many years of experience in nuclear astrophysics experiments at the overground HZDR 3 MV Tandetron accelerator [19][20][21][22][23][24] and on a long-standing involvement in the LUNA collaboration [10,11]. Complementary experiments studying the γ-widths of relevant levels [25,26] have been performed at the local bremsstrahlung facility [27] and are underway at the local neutron time-of-flight facility [28].…”

Mistycyzm ewangelikalny – źródła, podstawy, przejawy

“…Bóg jednak nie ogranicza się tylko do Pisma Świętego, ale może w danym zgromadzeniu bądź w konkretnych okolicznościach życia człowieka wlać w umysł i serce prorokującego jasne przesłanie w formie określonych zdań bądź obrazów domagających się interpretacji (zawsze prawdziwemu proroctwu przez obraz towarzyszy charyzmat interpretacji). Można tu wskazać na proroctwa kerygmatyczne (myśli i słowa), wizjonerskie (obrazy, sny), audytywne (słyszenie głosu) czy glosolalne (tłumaczenie języków) bądź wykorzystujące znak 47 . We współczesnym świecie charyzmatycznym proroctwo objawia się też przez wyrocznie, słowa zachęty, modlitwę natchnioną, prorocze pieśni, objawienia, proroctwa osobiste, wizje, prorocze akcje, słowo z Biblii 48 .…”