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Runkle, Robert C.; Champagne, Arthur E; Angulo, C.; Fox, C.; Iliadis, Christian; Longland, R.; Pollanen, J.

doi:10.1103/physrevlett.94.082503

Cited by 117 publications

(263 citation statements)

References 15 publications

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“…The main conclusion from the LUNA data has been confirmed by an independent study at higher energy [14]. However, there is a 15% discrepancy between the total Sfactors extrapolated by the two experiments at the Gamow peak of the Sun.…”

Section: O Reactionsupporting

confidence: 68%

Recent results on (p,γ) and (α,γ) fusion reactions at LUNA

Guglielmetti

2011

EPJ Web of Conferences

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Abstract. At temperatures typical of astrophysical environments, nuclear cross sections are extremely small and experimental measurements in a laboratory at the Earth's surface are hampered by the cosmic background. The LUNA collaboration has exploited the unique features of background reduction offered by the rock overburden above the LNGS underground laboratory in order to study very important hydrogen-burning reactions at their relevant astrophysical energies. After a general introduction on the LUNA experiment, this paper reports on the most important results for the (p,) and (,) fusion reactions measured so far and their astrophysical consequences. A quick look on the future possibilities is also given.

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Section: O Reactionsupporting

confidence: 68%

Recent results on (p,γ) and (α,γ) fusion reactions at LUNA

Guglielmetti

2011

EPJ Web of Conferences

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“…The main conclusion from the LUNA data has been confirmed by an independent study at higher energy [15]. However, there is a 15% discrepancy between the total S-factors extrapolated by the two experiments at the Gamow peak of the Sun.…”

Section: Pos(enas 6)057supporting

confidence: 67%

“…Five different radiative-capture transitions that contribute to the 14 N(p,γ) 15 O cross section at low energy were identified and measured.…”

Section: Pos(enas 6)057mentioning

confidence: 99%

“…The luminosity of the turnoff point in the Hertzsprung-Russell diagram of a globular cluster, namely the point at which the main sequence turns toward cooler and brighter stars, is used to determine the age of the cluster and to derive a lower limit on the age of the universe [8]. For a star at the turnoff point hydrogen shell burning is powered by the CNO cycle and therefore the 14 N(p,γ) 15 O cross section plays a crucial role in the age determination: the higher the cross section , the younger the globular cluster's age for a given turn-off luminosity.…”

Section: Why Underground: the Luna Projectmentioning

confidence: 99%

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Nuclear astrophysics at LUNA: recent results

Guglielmetti¹

2013

Proceedings of VI European Summer School on Experimental Nuclear Astrophysics — PoS(ENAS 6)

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At temperatures typical of astrophysical environments, nuclear cross sections are extremely small and experimental measurements in a laboratory at the Earth's surface are hampered by the cosmic background. The LUNA collaboration has exploited the unique features of background reduction offered by the rock overburden above the LNGS underground laboratory in order to study very important hydrogen-burning reactions at their relevant astrophysical energies. After a general introduction on the LUNA experiment, this paper reports on the most important results obtained so far and their astrophysical consequences. An overview on the future possibilities of this experiment through a consistent upgrade of the available experimental apparatus is also given.

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“…In particular, the experiment performed by the LUNA collaboration (Imbriani et al 2005;Costantini et al 2009) has reached the lowest energy, about 70 keV, which corresponds to a stellar temperature of about 50 MK. It is worth noting that a reliable extrapolation of the LUNA data to the solar Gamow peak requires combining low-energy with high-energy data, namely the results of the LENA experiment at TUNL (Runkle et al 2005). Additional information is provided by experiments that used indirect methods, such as the Doppler shift attenuation method (Bertone et al 2001;Schürmann et al 2008), Coulomb excitation (Yamada et al 2004), and asymptotic normalization coefficients (ANC; Mukhamedzhanov et al 2003).…”

Section: Reaction Rate Uncertaintiesmentioning

confidence: 99%

Effects of nuclear cross sections on¹⁹F nucleosynthesis at low metallicities

Cristallo

Leva

Imbriani

et al. 2014

A&A

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Context. The origin of fluorine is a longstanding problem in nuclear astrophysics. It is widely recognized that asymptotic giant branch (AGB) stars are among the most important contributors to the Galactic fluorine production. Aims. In general, extant nucleosynthesis models overestimate the fluorine production by AGB stars with respect to observations. Although those differences are rather small at solar metallicity, low metallicity AGB stellar models predict fluorine surface abundances up to one order of magnitude larger than the observed ones. Methods. As part of a project devoted to reducing the uncertainties in the nuclear physics that affect the nucleosynthesis in AGB stellar models, we review the relevant nuclear reaction rates involved in the fluorine production or destruction. We perform this analysis on a model with initial mass M = 2 M and Z = 0.001. Results. We found that the major uncertainties are due to the 13 C(α,n) 16 O, the 19 F(α,p) 22 Ne, and the 14 N(p,γ) 15 O reactions. A change in the corresponding reaction rates within the present experimental uncertainties implies surface 19 F variations at the AGB tip lower than 10%, thus much smaller than observational uncertainties. For some α capture reactions, however, cross sections at astrophysically relevant energies are determined on the basis of nuclear models, in which some low-energy resonance parameters are very poorly known. Thus, larger variations in the rates of those processes cannot be excluded. That being so, we explore the effects of the variation in some α capture rates well beyond the current published uncertainties. The largest 19 F variations are obtained by varying the 15 N(α,γ) 19 F and the 19 F(α,p) 22 Ne reactions. Conclusions. The currently estimated uncertainties of the nuclear reaction rates involved in the production and destruction of fluorine produce minor 19 F variations in the ejecta of AGB stars. Analysis of some α capture processes that assume a wider uncertainty range determines 19 F abundances in better agreement with recent spectroscopic fluorine measurements at low metallicity. In the framework of this scenario, the 15 N(α,γ) 19 F and the 19 F(α,p) 22 Ne reactions show the strongest effects on fluorine nucleosynthesis. The presence of poorly known low-energy resonances make such a scenario possible, even if it is unlikely. We plan to measure these resonances directly.

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Direct Measurement of theN14(p,γ)O15
Robert C. Runkle
¹
,
Arthur E Champagne
²
,
C. Angulo
³

et al.

Cited by 117 publications

References 15 publications

Recent results on (p,γ) and (α,γ) fusion reactions at LUNA

Recent results on (p,γ) and (α,γ) fusion reactions at LUNA

Nuclear astrophysics at LUNA: recent results

Effects of nuclear cross sections on¹⁹F nucleosynthesis at low metallicities

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Direct Measurement of theN14(p,γ)O15Robert C. Runkle1, Arthur E Champagne2, C. Angulo3 et al.

Cited by 117 publications

References 15 publications

Recent results on (p,γ) and (α,γ) fusion reactions at LUNA

Recent results on (p,γ) and (α,γ) fusion reactions at LUNA

Nuclear astrophysics at LUNA: recent results

Effects of nuclear cross sections on19F nucleosynthesis at low metallicities

Contact Info

Product

Resources

About

Direct Measurement of theN14(p,γ)O15
Robert C. Runkle
¹
,
Arthur E Champagne
²
,
C. Angulo
³

et al.

Effects of nuclear cross sections on¹⁹F nucleosynthesis at low metallicities