R-process nucleosynthesis in core-collapse supernova explosion

Kajino, T.; Wanajo, S.; Mathews, G. J.

doi:10.1016/s0375-9474(02)00777-7

Cited by 16 publications

(15 citation statements)

References 30 publications

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“…This may lead to a slightly smaller neutron-to-seed ratio at the onset of r-process, and hence make an appreciable influence on the entropy condition and expansion dynamics of the neutrino-driven wind [4]. Kajino et al have recently studied the sensitivity of the r-process yields to the α(αn, γ) 9 Be reaction rate, and found that a factor of two larger rate would change the final r-process abundances drastically in rapid expansion models of the neutrino-driven wind [45]. These possible implications should be studied in detail by using the present new reaction rate.…”

Section: Summary and Discussionmentioning

confidence: 99%

Astrophysical reaction rate for α(αn,γ)9Be by photodisintegration

et al. 2002

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We study the astrophysical reaction rate for the formation of 9 Be through the three body reaction α(αn, γ). This reaction is one of the key reactions which could bridge the mass gap at A = 8 nuclear systems to produce intermediate-to-heavy mass elements in alpha-and neutron-rich environments such as r-process nucleosynthesis in supernova explosions, s-process nucleosynthesis in asymptotic giant branch (AGB) stars, and primordial nucleosynthesis in baryon inhomogeneous cosmological models. To calculate the thermonuclear reaction rate in a wide range of temperatures, we numerically integrate the thermal average of cross sections assuming a two-steps formation through a metastable 8 Be, α + α ⇀ ↽ 8 Be(n,γ) 9 Be. Off-resonant and on-resonant contributions from the ground state in 8 Be are taken into account. As input cross section, we adopt the latest experimental data by photodisintegration of 9 Be with laser-electron photon beams, which covers all relevant resonances in 9 Be. Experimental data near the neutron threshold are added with γ-ray flux corrections and a new least-squares analysis is made to deduce resonance parameters in the Breit-Wigner formulation. Based on the photodisintegration cross section, we provide the reaction rate for α(αn, γ) 9 Be in the temperature range from T 9 =10 −3 to T 9 =10 1 (T 9 is the temperature in units of 10 9 K) both in the tabular form and in the analytical form for potential usage in nuclear reaction network calculations.The calculated reaction rate is compared with the reaction rates of the CF88 and the NACRE compilations. The CF88 rate, which is based on the photoneutron cross section for the 1/2 + state in 9 Be by Berman et al., is valid at T 9 > 0.028 due to lack of the off-resonant contribution. The CF88 rate differs from the present rate by a factor of two in a temperature range T 9 ≥ 0.1. The NACRE rate, which adopted different sources of experimental information on resonance states in 9 Be, is 4-12 times larger than the present rate at T 9 ≤ 0.028, but is consistent with the present rate to within ±20% at T 9 ≥ 0.1. 2

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Section: Summary and Discussionmentioning

confidence: 99%

Astrophysical reaction rate for α(αn,γ)9Be by photodisintegration

et al. 2002

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“…The reaction rate for 8 Li(α,n) 11 B is taken from Gu et al (1995). This reaction was identified to be a critical nuclear reaction of producing the intermediate-to-heavy mass elements in some inhomogeneous Big-Bang nucleosynthesis models (Malaney & Fowler 1988, Boyd & Kajino 1989, Kajino & Boyd 1990 as well as for r-process nucleosynthesis (Terasawa et al 2001, Kajino, Wanajo & Mathews 2002. Ishiyama et al (2004) have recently carried out very precise measurements of the exclusive reaction cross section for 8 Li(α, n) 11 B * as well as for 8 Li(α, n) 11 B gs .…”

Section: Li(nγ) 8 LImentioning

confidence: 99%

Sensitivity ofr‐Process Nucleosynthesis to Light‐Element Nuclear Reactions

Sasaqui

Kajino

Mathews

et al. 2005

ApJ

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-We study the efficiency and sensitivity of r-process nucleosynthesis to 18 lightelement nuclear reaction rates. We adopt empirical power-law relations to parameterize the reaction sensitivities. We utilize two different hydrodynamic models for the neutrino-driven winds in order to study the dependence of our result on supernova wind models. We also utilize an exponential model to approximate a wide variety of other plausible conditions for the r-process. We identify several specific nuclear reactions among light neutron-rich nuclei that play a critical role in determining the final r-process nucleosynthesis yields. As an illustration, we examine "semi-waiting" points among the carbon isotopes. We show that not only neutron capture and β-decay, but also (α, n) reactions are important in determining waiting points along the r-process path. Our numerical results from this sensitivity analysis serve foremost to clarify which light nuclear reactions are most influential in determining the final r-process abundances. We also quantify the effects of present nuclear uncertainties on the final r-process abundances. This study thus emphasizes and motivates which future determinations of nuclear reaction rates will most strongly impact our understanding of r-process nucleosynthesis.

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“…These nuclei are important for analysis of the r-process in stars [35][36][37]. As in the previous Sec.…”

Section: Two-neutron Drip Linementioning

confidence: 78%

“…This part of the nuclear chart is important for the study of the r-process in stars [35][36][37]. The consideration is made within a standard approach with fixed EDF parameters found mainly for stable nuclei.…”

Section: Discussionmentioning

confidence: 99%

“…Recent interest to the problem of fixing the neutron drip line [33,34] is partially induced with importance of this characteristic of the nuclear chart for analysis of the r-process dynamics in stars [35][36][37]. A couple of remarks should be made concerning validity of the EDF method with fixed set of parameters for predicting the drip lines.…”

Section: Introductionmentioning

confidence: 99%

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Fayans functional for deformed nuclei. Uranium region

Tolokonnikov

Borzov

Kortelainen

et al. 2016

EPJ Web of Conferences

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Abstract. Fayans energy density functional (EDF) FaNDF 0 has been applied to the nuclei around uranium region. Ground state characteristics of the Th, U and Pu isotopic chains, up to the two-neutron drip line, are found and compared with predictions from several Skyrme EDFs. The two-neutron drip line is found for FaNDF 0 , SLy4 and SkM * EDFs for a set of elements with even proton number, from Pb up to Fm.

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R-process nucleosynthesis in core-collapse supernova explosion

Cited by 16 publications

References 30 publications

Astrophysical reaction rate for α(αn,γ)9Be by photodisintegration

Astrophysical reaction rate for α(αn,γ)9Be by photodisintegration

Sensitivity ofr‐Process Nucleosynthesis to Light‐Element Nuclear Reactions

Fayans functional for deformed nuclei. Uranium region

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