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相关论文: The thermonuclear rate for the 19F(a,p)22Ne reacti…

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In the light of recent recalculations of the \el{19}{F}(alpha,p)\el{22}{Ne} reaction rate we present results of the expected yield of \el{19}{F} from Wolf-Rayet (WR) stars. We have computed models using the upper and lower limits for the…

天体物理学 · 物理学 2011-07-19 R. J. Stancliffe , M. Lugaro , C. Ugalde , C. A. Tout , J. Gorres , M. Wiescher

We present nucleosynthesis calculations and the resulting 19F stellar yields for a large set of models with different masses and metallicity. We find that the production of fluorine depends on the temperature of the convective pulses, the…

The recent experimental evaluation of the 18F(a,p)21Ne reaction rate, when considering its associated uncertainties, presented significant differences compared to the theoretical Hauser-Feshbach rate. This was most apparent at the low…

天体物理学 · 物理学 2008-12-12 Amanda I. Karakas , Hye Young Lee , Maria Lugaro , J. Goerres , Michael Wiescher

The thermonuclear $^{19}$F($p$,$\alpha_0$)$^{16}$O reaction rate in a temperature region of 0.007--10 GK has been derived by re-evaluating the available experimental data, together with the low-energy theoretical $R$-matrix extrapolations.…

太阳与恒星天体物理 · 物理学 2018-01-17 J. J. He , I. Lombardo , D. Dell'Aquila , Y. Xu , L. Y. Zhang , W. P. Liu

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. In general, extant…

太阳与恒星天体物理 · 物理学 2014-10-15 S. Cristallo , A. Di Leva , G. Imbriani , L. Piersanti , C. Abia , L. Gialanella , O. Straniero

We present detailed models of low and intermediate-mass asymptotic giant branch (AGB) stars with and without the 18F(a,p)21Ne reaction included in the nuclear network, where the rate for this reaction has been recently experimentally…

天体物理学 · 物理学 2009-11-13 Amanda Karakas , Hye Young Lee , Maria Lugaro , Joachim Goerres , Michael Wiescher

We investigate the abundance of $^{19}F$ in the Sun through the nucleosynthesis scenario. In addition, we calculate the rate equations and reaction rates of the nucleosynthesis of $^{19}F$ at different temperature scale. Other important…

At temperatures below 0.1 GK the $^{19}$F$(p,\gamma)^{20}$Ne reaction is the only breakout path out of the CNO cycle. Experimental studies of this reaction are challenging from a technical perspective due to copious $\gamma$-ray background…

核实验 · 物理学 2022-06-14 M. Williams , P. Adsley , B. Davids , U. Greife , D. Hutcheon , J. Karpesky , A. Lennarz , M. Lovely , C. Ruiz

The early E < 511 keV gamma-ray emission from novae depends critically on the 18F(p,a)15O reaction. Unfortunately the reaction rate of the 18F(p,a)15O reaction is still largely uncertain due to the unknown strengths of low-lying proton…

The $^{18}{\rm O}(p,\alpha)^{15}{\rm N}$ reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside AGB stars as well as oxygen and nitrogen isotopic ratios in meteorite grains. Thus the…

For stars between 0.8-8.0 solar masses, nucleosynthesis enters its final phase during the asymptotic giant branch (AGB) stage. During this evolutionary period, grain condensation occurs in the stellar atmosphere, and the star experiences…

Detection of nuclear-decay $\gamma$ rays provides a sensitive thermometer of nova nucleosynthesis. The most intense $\gamma$-ray flux is thought to be annihilation radiation from the $\beta^+$ decay of $^{18}$F, which is destroyed prior to…

Uncertainties in the thermonuclear rates of the $^{15}$O($\alpha,\gamma$)$^{19}$Ne and $^{18}$F($p,\alpha$)$^{15}$O reactions affect model predictions of light curves from type I X-ray bursts and the amount of the observable radioisotope…

The current status of the reaction rate of $^{22}$Ne($\alpha$,n)$^{25}$Mg is summarized. Among the latest new results, probably the most relevant is the conclusion that the E$_x$=11.15 MeV state in $^{26}$Mg has a non-natural parity, so it…

核实验 · 物理学 2008-10-08 Claudio Ugalde

A recently published letter reports a measurement of alpha decay from states in 19Ne at excitation energies below 4.5 MeV. The measured alpha decay branching ratios B_alpha are used to calculate the astrophysical rate of the…

核实验 · 物理学 2008-04-15 B. Davids

Updated stellar rates for the reaction 23Mg(p,gamma)24Al are calculated by using all available experimental information on 24Al excitation energies. Proton and gamma-ray partial widths for astrophysically important resonances are derived…

核理论 · 物理学 2008-11-26 H. Herndl , M. Fantini , C. Iliades , P. M. Endt , H. Oberhummer

New models of rotating and non-rotating stars are computed for initial masses between 25 and 120 Msun and for metallicities Z = 0.004, 0.008, 0.020 and 0.040 with the aim of reexamining the wind contribution of Wolf-Rayet (WR) stars to the…

天体物理学 · 物理学 2009-11-11 A. Palacios , M. Arnould , G. Meynet

Meynet and Arnould (1993) have suggested that Wolf-Rayet (WR) stars could significantly contaminate the Galaxy with 19F. In their scenario, 19F is synthesized at the beginning of the He-burning phase from the 14N left over by the previous…

天体物理学 · 物理学 2007-05-23 G. Meynet , M. Arnould

The 16O(p,gamma)17F reaction rate is revisited with special emphasis on the stellar temperature range of T=60-100 MK important for hot bottom burning in asymptotic giant branch (AGB) stars. We evaluate existing cross section data that were…

天体物理学 · 物理学 2009-06-23 C. Iliadis , C. Angulo , P. Descouvemont , M. Lugaro , P. Mohr

The $^{14}$O($\alpha$,$p$)$^{17}$F reaction is one of the key reactions involved in the breakout from the hot-CNO cycle to the rp-process in type I x-ray bursts (XRBs). The resonant properties in the compound nucleus $^{18}$Ne have been…

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