Author:
Brown Jesse M.,Guber Klaus H.,Paradela Carlos,Schillebeeckx Peter,Kopecky Stefan
Abstract
The isotopes of Zr with A = [90, 91, 92, 94] make up more than 97% of naturally occurring Zr and are important to many nuclear applications such as nuclear reactors. One of the attractive qualities of naturally occurring Zr isotopes is that they have a low σγ/σt ratio at most neutron energies. Thus, they improve the neutron economy in reactors by preferentially scattering neutrons rather than absorbing them. This same quality also presents a challenge to measuring the capture cross section, σγ, of Zr isotopes. The ENDF/B-VIII.0 library has a relative uncertainty of approximately 10–20% for incident neutron energies < 0.1 MeV and an uncertainty greater than 20% for energies > 0.1 MeV for the majority of natural Zr isotopes. This motivated the Nuclear Criticality Safety Program to embark on a campaign to accurately measure and evaluate these Zr isotopes. In this work, we demonstrate energy-dependent neutron capture cross section measurements for the first enriched sample to be measured: 90Zr.
Reference7 articles.
1. Neutron capture cross section ofZr90: Bottleneck in thes-process reaction flow
2. TheZr92(n,γ) reaction and its implications for stellar nucleosynthesis
3. Brown J.M., Wiarda D., Guber K.H., Tech. Rep. ORNL/TM-2019/1300, Oak Ridge National Laboratory, Oak Ridge, TN, USA (2019)
4. Baum E.M. et al., Nuclides and Isotopes: Chart of the Nuclides, 17th edn. (Bechtel Marine Propulsion Corporation, Schenectady, NY, USA, 2010), ISBN 978-0-9843653-1-9
5. Neutron Radiative Capture and Transmission Measurements of W and Zr Isotopes in the keV Region