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

TL;DR

This paper reports a precise measurement of the Am-243 neutron capture cross section at CERN's n_TOF facility, extending the resonance region and providing data to reduce existing uncertainties for nuclear reactor applications.

Contribution

The study provides new experimental data on Am-243 neutron capture cross section, extending the resonance region and comparing with existing data to improve nuclear data libraries.

Findings

Extended the resolved resonance region from 250 eV to 400 eV.

Found the cross section may be underestimated by up to 25% in current libraries.

Contributed data helps reduce the uncertainty in Am-243 neutron capture cross section.

Abstract

Background:The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Reduce the $^{243}$Am(n,$\gamma$) cross section uncertainty. Method: The $^{243}$Am(n,$\gamma$) cross section has been measured at the n_TOF facility at CERN with a BaF$_{2}$ Total Absorption Calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The $^{243}$Am(n,$\gamma$) 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 has been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the $^{243}$Am(n,$\gamma$) 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.