Re-evaluation of the ¹⁶O(n, γ)¹⁷O cross section at astrophysical energies and its role as a neutron poison in the s-process

Mohr, Peter; Heinz, Christian; Pignatari, Marco; Dillmann, Iris; Mengoni, Alberto; Käppeler, Franz

Abstract

The doubly magic nucleus ¹⁶O has a small neutron-capture cross section of just a few tens of microbarns in the astrophysical energy region. Despite this, ¹⁶O plays an important role as a neutron poison in the astrophysical slow neutron capture (s) process due to its high abundance. We present in this paper a re-evaluation of the available experimental data for ¹⁶O(n, γ)¹⁷O and derive a new recommendation for the Maxwellian-averaged cross sections between kT = 5 and 100 keV. Our new recommendations are lower up to kT = 60 keV compared to the previously recommended values but up to 14% higher at kT = 100 keV. We explore the impact of this different energy dependence on the weak s-process during core helium burning (kT = 26 keV) and shell carbon burning (kT = 90 keV) in massive stars where ¹⁶O is the most abundant isotope.

Citation

Mohr, P., Heinz, C., Pignatari, M., Dillmann, I., Mengoni, A., & Käppeler, F. (2016). Re-evaluation of the ¹⁶O(n, γ)¹⁷O cross section at astrophysical energies and its role as a neutron poison in the s-process. The Astrophysical journal, 827(1), Article ARTN 29. https://doi.org/10.3847/0004-637X/827/1/29

• Journal Article Type: Article
• Acceptance Date: Apr 29, 2016
• Online Publication Date: Aug 3, 2016
• Publication Date: Aug 10, 2016
• Deposit Date: Aug 5, 2016
• Publicly Available Date: Aug 5, 2016
• Journal: Astrophysical journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 827
• Issue: 1
• Article Number: ARTN 29
• DOI: https://doi.org/10.3847/0004-637X/827/1/29
• Keywords: ¹⁶O(n, γ)¹⁷O cross section , Stars: massive, s-process
• Public URL: https://hull-repository.worktribe.com/output/442060
• Publisher URL: http://iopscience.iop.org/article/10.3847/0004-637X/827/1/29/meta;jsessionid=9DD4B9611E3BDFCE2CCFB67382448C44.c1.iopscience.cld.iop.org
• Additional Information: Journal title: The Astrophysical Journal; Article type: paper; Article title: RE-EVALUATION OF THE16O(N,γ)17O CROSS SECTION AT ASTROPHYSICAL ENERGIES AND ITS ROLE AS A NEUTRON POISON IN THEs-PROCESS; Copyright information: © 2016. The American Astronomical Society. All rights reserved.; Date received: 2016-02-11; Date accepted: 2016-04-29; Online publication date: 2016-08-03