Measurement and analysis of the 243 Am neutron capture cross section at the n_TOF facility at CERN

Background: The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Improvement of the Am243(n,γ) cross section uncertainty. Method: The Am243(n,γ) cross section has been measured at the n-TOF facility at CERN with a BaF2 total absorption calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The Am243(n,γ) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature have been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the Am243(n,γ) cross section uncertainty and suggest that this cross section is underestimated up to 25% in the neutron energy range between 50 eV and a few keV in the present evaluated data libraries.Ministerio de Economía y Competitividad (España) FPA2011-28770-C03-01Programa de la Comisión Europea IP-EUROTRANS F16W-CT-2004-516520Consolider-Ingenio CSD-2007-0004