Absolute Partial γ-ray Cross Sections in 238U(n, xny) Reactions

Autor: Fotiades, Nikolaos, Johns, Glen D., Nelson, Ronald O., Chadwick, Mark B., Devlin, Matthew, Wilburn, Wesley S., Young, Phillip G., Archer, Daniel E., Becker, John A., Bernstein, Lee A., Mcgrath, Christopher A., Garrett, Paul E., Mcnabb, Dennis P., Younes, Walid
Zdroj: Journal of Nuclear Science and Technology; August 2002, Vol. 39 Issue: Supplement 2 p234-237, 4p
Abstrakt: Measurements of discrete γ-ray spectra have been carried out as a function of incident-neutron energy for nuclei populated in 238U(n, xnγ(x≤ 4) reactions. The GEANIE spectrometer, comprised of 26 Ge detectors (11 planar and 15 coaxial), was used to detect γ-rays. Neutrons were provided by the “white” neutron source of the Los Alamos Neutron Science Center’s WNR facility. The energy of the incident neutrons was determined using the time-of-flight technique. Absolute cross sections were determined for emission of several γ-rays from low-lying states of 235-238U isotopes (spin up to 10ħand excitation energy up to ~1 MeV) as a function of incident-neutron energy (1 MeV< En100 MeV). Uncertainties associated with the spectroscopic analysis of the data are discussed. Predictions of partial γ-ray cross sections from GNASH calculations up to neutron energy En= 30 MeVare compared to the experimental results and are generally in good agreement. Combining the experimental results with the predictions of the nuclear reaction modeling provides a measurement of the 238U(n, n′) reaction cross section and validate this technique for determining reaction cross sections using γ-ray spectroscopy.
Databáze: Supplemental Index