Neutron-capture Studies on (235)U and (238)U via AMS

Author(s)

Anton Wallner, Kathrin Buczak, Francesca Quinto, Peter Steier, Tamás Belgya, L. Szentmiklosi, Max Bichler, I Dillmann, Franz Käppeler, Alberto Mengoni

Abstract

Major nuclear data libraries exhibit some discrepancies for the neutron capture reactions (235)U(n,gamma) and (238)U(n,gamma) at keV energies. These differences reflect also the scatter of experimental data that are primarily based on time-of-flight measurements (TOF) with detection of prompt gamma-rays. We report here on an independent approach for studying such reactions: Neutron activations with subsequent accelerator mass spectrometry (AMS) measurement represent an independent technique, where interference from fission is completely excluded. Activations of natural uranium samples were performed with cold neutrons (Budapest), thermal (Vienna) and with neutrons of 25 and 500 keV (Karlsruhe) for the measurement of (235)U(n,gamma) and (238)U(n,gamma). The produced long-lived (236)U and the decay product of (239)U, (239)Pu, respectively, were subsequently counted by AMS at the Vienna Environmental Research Accelerator. This method for measuring the neutron capture cross section has the advantage that the involved systematic uncertainties are in no way correlated with those inherent to the TOF technique. Preliminary data for these neutron energies indicate good agreement with evaluations and seem to support in the keV energy range the reported lower cross-section values for both capture reactions.

Organisation(s)

Isotope Physics

External organisation(s)

Hungarian Academy of Sciences, Karlsruher Institut für Technologie, International Atomic Energy Agency (IAEA), Technische Universität Wien

Journal

Journal of the Korean Physical Society

Volume

59

Pages

1410-1413

No. of pages

4

ISSN

0374-4884

DOI

https://doi.org/10.3938/jkps.59.1410

Publication date

2011

Peer reviewed

Yes

Austrian Fields of Science 2012

103005 Atomic physics

Portal url

https://ucrisportal.univie.ac.at/en/publications/d315a3b2-1bee-41ee-bcb1-2f9031cff2e4