Broad levels in $^{17}$O and their relevance for the astrophysical s-process
| Autor: | Faestermann, Thomas, Mohr, Peter, Hertenberger, Ralf, Wirth, Hans-Friedrich |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Phys. Rev. C 92, 052802(R) (2015) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevC.92.052802 |
| Popis: | Levels in $^{17}$O affect the astrophysical s-process in two opposite ways. The neutron production is enhanced by resonances in the $^{13}$C($\alpha$,$n$)$^{16}$O reaction at excitation energies around 7 MeV in $^{17}$O, and the number of available neutrons is reduced by low-lying resonances in the $^{16}$O($n$,$\gamma$)$^{17}$O reaction corresponding to levels in $^{17}$O with excitation energies of $4-5$ MeV. The present work uses the $^{19}$F($d$,$\alpha$)$^{17}$O reaction to determine absolute widths of the relevant levels in $^{17}$O. The results improve the uncertainties of the previously adopted values and resolve a discrepancy between recent studies for the $1/2^+$ level close to the threshold of the $^{13}$C($\alpha$,$n$)$^{16}$O reaction. In addition, improved excitation energies and widths are provided for several states in $^{17}$O up to excitation energies close to 8 MeV. Comment: 5 pages, 2 figures, Phys. Rev. C (in press) |
| Databáze: | arXiv |
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