論文

査読有り
2017年10月20日

The 95Zr(n, γ)96Zr Cross Section from the Surrogate Ratio Method and Its Effect on s-process Nucleosynthesis

Astrophysical Journal
  • S. Q. Yan
  • ,
  • Z. H. Li
  • ,
  • Y. B. Wang
  • ,
  • K. Nishio
  • ,
  • M. Lugaro
  • ,
  • A. I. Karakas
  • ,
  • H. Makii
  • ,
  • P. Mohr
  • ,
  • J. Su
  • ,
  • Y. J. Li
  • ,
  • I. Nishinaka
  • ,
  • K. Hirose
  • ,
  • Y. L. Han
  • ,
  • R. Orlandi
  • ,
  • Y. P. Shen
  • ,
  • B. Guo
  • ,
  • S. Zeng
  • ,
  • G. Lian
  • ,
  • Y. S. Chen
  • ,
  • W. P. Liu

848
2
開始ページ
98
終了ページ
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3847/1538-4357/aa8c74
出版者・発行元
Institute of Physics Publishing

The 95Zr(n, γ)96Zr reaction cross section is crucial in the modeling of s-process nucleosynthesis in asymptotic giant branch stars because it controls the operation of the branching point at the unstable 95Zr and the subsequent production of 96Zr. We have carried out the measurement of the 94Zr(18O, 16O) and 90Zr(18O, 16O) reactions and obtained the γ-decay probability ratio of 96Zr∗ and 92Zr∗ to determine the 95Zr(n, γ)96Zr reaction cross sections with the surrogate ratio method. Our deduced Maxwellian-averaged cross section of 66 ±16 mb at 30 keV is close to the value recommended by Bao et al., but 30% and more than a factor of two larger than the values proposed by Toukan &amp
Käppeler and Lugaro et al., respectively, and routinely used in s-process models. We tested the new rate in stellar models with masses between 2 and 6 M o and metallicities of 0.014 and 0.03. The largest changes - up to 80% variations in 96Zr - are seen in models of mass 3-4 M o, where the 22Ne neutron source is mildly activated. The new rate can still provide a match to data from meteoritic stardust silicon carbide grains, provided that the maximum mass of the parent stars is below 4 M o, for a metallicity of 0.03.

リンク情報
DOI
https://doi.org/10.3847/1538-4357/aa8c74

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