Production and isobaric separation of 63Ni ions for determination of the 62Ni(n,γ)63Ni reaction cross section at stellar temperatures

Nassar, Hisham; Ghelberg, S.; Paul, M.; Dababneh, S.; Heil, M.; Käppeler, F.; Plag, R.; Ahmad, I.; Greene, J. P.; Henderson, D. J.; Jiang, C.L.; Pardo, R. C.; Pennington, T.; Rehm, K.E.; Scott, Robert H.; Sinha, S.; Tang, Xiaodong; Vondrasek, R.; Koivisto, H.; Berkovits, D.; Bettan, M.; Reifarth, R.; Collon, P.; O’Brien, S.; Patronis, N.

doi:10.1016/j.nuclphysa.2004.09.140

Cited by 5 publications

(4 citation statements)

References 7 publications

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“…These calculated impact values highlight the impact of the uncertainties having the most extensive propagation effect on the isotopic abundances with the highest production factors. Such an effect is well known to be relevant for the weak s process, involving both isotopes beyond iron (see for instance the famous case of the 62 Ni(n,γ ) 63 Ni, e.g., [68]) and light isotopes (see, e.g, 25 Mg(n,γ ) 26 Mg [2,31,56] and 22 Ne(n,γ ) 23 Ne [25,58]). Note that, however, the impact values adopted here should not be considered as the only diag-Fig.…”

Section: Results Of the Nuclear Sensitivity Studymentioning

confidence: 99%

“…To discuss the impact of neutron-capture rate of heavy isotopes, in Fig. 3 we consider the examples of 58 Fe and 68 Zn (both are listed in Table 2) and 85 Kr at the end of the C- shell. For heavy stable isotopes, we can distinguish two types of propagation impact: one type for the isotopes 56−58 Fe and 59 Co behaving as direct or undirect seeds of the s-process production, and another one for all the other heavier species (including 68 Zn that will be discussed here).…”

Section: Results Of the Nuclear Sensitivity Studymentioning

confidence: 99%

“…For the isotopes in the second group we obtain a more clear propagation. For instance, 68 Zn, which has a low neutron-capture cross section of about 20 mb, is acting as a bottle-neck of the s-process flow: all the heavier s-process products are reduced consistently by decreasing the 68 Zn(n,γ ) 69 Zn (Fig. 3, middle panel).…”

Section: Results Of the Nuclear Sensitivity Studymentioning

confidence: 99%

“…Fig. 3 The isotopic ratios of the test cases normalized to the abundances obtained with the default model are reported at the end of the C shell for 58 Fe(n,γ ) 59 Fe (upper panel), 68 Zn(n,γ ) 69 Zn (central panel) and 85 Kr(n,γ ) 86 Kr (lower panel) Acknowledgements The bulk of the work presented here was built by repeating the nuclear sensitivity study designed and recommended by Franz Käppeler twenty years ago, which became a crucial driver for several discoveries and scientific publications made with Franz and many other collaborators. We are deeply grateful for Franz's friendship and kindness along these years.…”

Section: Discussionmentioning

confidence: 99%

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The s process in massive stars, a benchmark for neutron capture reaction rates

Pignatari,

Gallino,

Reifarth

2023

Eur. Phys. J. A

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A clear definition of the contribution from the slow neutron-capture process (s process) to the solar abundances between Fe and the Sr-Zr region is a crucial challenge for nuclear astrophysics. Robust s-process predictions are necessary to disentangle the contribution from other stellar processes producing elements in the same mass region. Nuclear uncertainties are affecting s-process calculations, but most of the needed nuclear input are accessible to present nuclear experiments or they will be in the near future. Neutron-capture rates have a great impact on the s process in massive stars, which is a fundamental source for the solar abundances of the lighter s-process elements heavier than Fe (weak s-process component). In this work we present a new nuclear sensitivity study to explore the impact on the s process in massive stars of 86 neutron-capture rates, including all the reactions between C and Si and between Fe and Zr. We derive the impact of the rates at the end of the He-burning core and at the end of the C-burning shell, where the $$^{22}$$ 22 Ne($$\alpha $$ α ,n)$$^{25}$$ 25 Mg reaction is is the main neutron source. We confirm the relevance of the light isotopes capturing neutrons in competition with the Fe seeds as a crucial feature of the s process in massive stars. For heavy isotopes we study the propagation of the neutron-capture uncertainties, finding a clear difference of the impact of Fe and Co isotope rates with respect to the rates of heavier stable isotopes. The local uncertainty propagation due to the neutron-capture rates at the s-process branching points is also considered, discussing the example of $$^{85}$$ 85 Kr. The complete results of our study for all the 86 neutron-capture rates are available online. Finally, we present the impact on the weak s process of the neutron-capture rates included in the new ASTRAL library (v0.2).

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Section: Results Of the Nuclear Sensitivity Studymentioning

confidence: 99%

Section: Results Of the Nuclear Sensitivity Studymentioning

confidence: 99%

Section: Results Of the Nuclear Sensitivity Studymentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

The s process in massive stars, a benchmark for neutron capture reaction rates

Pignatari,

Gallino,

Reifarth

2023

Eur. Phys. J. A

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Nuclear astrophysics and AMS – Probing nucleosynthesis in the lab

Wallner

2010

Nuclear Instruments and Methods in Physics Research Section B:

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Stellar(n,γ)Cross Section ofNi62

Nassar¹,

Paul²,

Ahmad³

et al. 2005

Phys. Rev. Lett.

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The 62Ni(n,gamma)63Ni(t(1/2)=100+/-2 yr) reaction plays an important role in the control of the flow path of the slow neutron-capture (s) nucleosynthesis process. We have measured for the first time the total cross section of this reaction for a quasi-Maxwellian (kT=25 keV) neutron flux. The measurement was performed by fast-neutron activation, combined with accelerator mass spectrometry to detect directly the 63Ni product nuclei. The experimental value of 28.4+/-2.8 mb, fairly consistent with a recent calculation, affects the calculated net yield of 62Ni itself and the whole distribution of nuclei with 62

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Production and isobaric separation of 63Ni ions for determination of the 62Ni(n,γ)63Ni reaction cross section at stellar temperatures

Cited by 5 publications

References 7 publications

The s process in massive stars, a benchmark for neutron capture reaction rates

The s process in massive stars, a benchmark for neutron capture reaction rates

Nuclear astrophysics and AMS – Probing nucleosynthesis in the lab

Stellar(n,γ)Cross Section ofNi62

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