Novel Method to Study Neutron Capture of U-235 and U-238 Simultaneously at keV Energies

Autor(en)

A. Wallner, T. Belgya, M. Bichler, K. Buczak, I. Dillmann, F. Kaeppeler, C. Lederer, A. Mengoni, F. Quinto, P. Steier, L. Szentmiklosi

Abstrakt

The neutron capture cross sections of the main uranium isotopes, U235 and U238,

were measured simultaneously for keV energies, for the first time by

combining activation technique and atom counting of the reaction

products using accelerator mass spectrometry. New data, with a precision

of 3%–5%, were obtained from mg-sized natural uranium samples for

neutron energies with an equivalent Maxwell-Boltzmann distribution of kT∼25  keV and for a broad energy distribution peaking at 426 keV. The cross-section ratio of U235(n,γ)/U238(n,γ) can be deduced in accelerator mass spectrometry directly from the atom ratio of the reaction products U236/U239,

independent of any fluence normalization. Our results confirm the

values at the lower band of existing data. They serve as important

anchor points to resolve present discrepancies in nuclear data libraries

as well as for the normalization of cross-section data used in the

nuclear astrophysics community for s-process studies.

Organisation(en)

Isotopenphysik

Externe Organisation(en)

Technische Universität Wien, Karlsruher Institut für Technologie, Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile, Hungarian Academy of Sciences, University of British Columbia (UBC), Johann Wolfgang Goethe-Universität Frankfurt am Main, Australian National University

Journal

Physical Review Letters

Band

112

Anzahl der Seiten

6

ISSN

0031-9007

DOI

https://doi.org/10.1103/PhysRevLett.112.192501

Publikationsdatum

05-2014

Peer-reviewed

Ja

ÖFOS 2012

103014 Kernphysik, 103004 Astrophysik

Schlagwörter

Link zum Portal

https://ucris.univie.ac.at/portal/de/publications/novel-method-to-study-neutron-capture-of-u235-and-u238-simultaneously-at-kev-energies(0780154c-6774-4e6a-85bf-27e3db9cc9c2).html