Two absolute integral measurements of the 197Au(n,γ) stellar cross-section and solution of the historic discrepancies

Autor: Praena Javier, Jiménez-Bonilla Pablo
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: EPJ Web of Conferences, Vol 239, p 19002 (2020)
Druh dokumentu: article
ISSN: 2100-014X
DOI: 10.1051/epjconf/202023919002
Popis: The Maxwellian averaged cross section (MACS) for 197Au(n,γ) is used in neutron capture cross section measurements as a reference for reactions important for astrophysics, reactor and dosimetry applications. The traditionally adopted value for this reference cross section, in the energy range relevant for astrophysical (3 < E n < 200 keV), was obtained by Ratynski and Käppeler in 1988. However, the MACS calculated using the 2006 standards evaluation is approximately 6 % above the Ratynski and Käppeler (R&K) evaluation. Because of this discrepancy new experiments and reanalyses were done in an attempt to resolve the problem. In 2011 we started as well a series of integral experiments (activation) for determining the MACS-30 (kT=30 keV) of Au with two different Maxwellian neutron spectra: i) QMNS-25 (as R&K) and ii) MNS-30 (new method). Our results agree with those obtained with the standard evaluation. At present (2018), the updated MACS-30 has been included as standard. Here we present the results of our measurements and the reasons for the lower value of the R&K measurement.
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