Precise measurement of the thermal and stellar Fe54(n,γ)Fe55 cross sections via accelerator mass spectrometry
| Autor: | Marco Pignatari, Alberto Mengoni, Alfred Priller, Anton Wallner, Tamás Belgya, Amanda I. Karakas, Peter Steier, L. Coquard, C. Lederer, László Szentmiklósi, Rene Reifarth, F. Käppeler, Walter Kutschera, Max Bichler, Robin Golser, I. Dillmann, K Buczak |
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| Rok vydání: | 2017 |
| Předmět: |
Nuclear reaction
Physics 010308 nuclear & particles physics 7. Clean energy 01 natural sciences Nuclear physics Neutron capture Stars 13. Climate action 0103 physical sciences Thermal Nuclear astrophysics Asymptotic giant branch Neutron Atomic physics 010306 general physics Accelerator mass spectrometry |
| Zdroj: | Physical Review C. 96 |
| ISSN: | 2469-9993 2469-9985 |
| Popis: | Accelerator mass spectrometry (AMS) represents a complementary approach for precise measurements of neutron capture cross sections, e.g., for nuclear astrophysics. This technique, completely independent of previous experimental methods, was applied for the measurement of the $^{54}\mathrm{Fe}(n,\ensuremath{\gamma})^{55}\mathrm{Fe}$ reaction. Following a series of irradiations with neutrons from cold and thermal to keV energies, the produced long-lived $^{55}\mathrm{Fe}$ nuclei (${t}_{1/2}=2.744+\ensuremath{-}0.009)$ yr) were analyzed at the Vienna Environmental Research Accelerator. A reproducibility of about 1% could be achieved for the detection of $^{55}\mathrm{Fe}$, yielding cross-section uncertainties of less than 3%. Thus, this method produces new and precise data that can serve as anchor points for time-of-flight experiments. We report significantly improved neutron capture cross sections at thermal energy (${\ensuremath{\sigma}}_{\mathrm{th}}=2.30\ifmmode\pm\else\textpm\fi{}0.07$ b) as well as for a quasi-Maxwellian spectrum of $kT=25$ keV ($\ensuremath{\sigma}=30.3\ifmmode\pm\else\textpm\fi{}1.2$ mb) and for ${E}_{n}=481\ifmmode\pm\else\textpm\fi{}53$ keV ($\ensuremath{\sigma}=6.01\ifmmode\pm\else\textpm\fi{}0.23$ mb). The new experimental cross sections have been used to deduce improved Maxwellian-averaged cross sections in the temperature regime of the common $s$-process scenarios. The astrophysical impact is discussed by using stellar models for low-mass asymptotic giant branch stars. |
| Databáze: | OpenAIRE |
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