SYMPOSIA PAPER Published: 01 January 1994

Measurement of U Fission Spectrum-Averaged Cross Sections for Some Threshold Reactions


The 233U fission spectrum-averaged cross sections for twelve threshold reactions were measured relative to the average cross section of 0.688±0.040 mb for the 27Al(n,α)24Na reaction. The reference value was obtained by calculation using the energy dependent cross section in the Japanese Evaluated Nuclear Data Library (JENDL) Dosimetry File and the Watt-type fission spectrum in ENDF/B-VI. General agreement was seen between the measured and the calculated fission-spectrum averaged cross sections. However, there exist discrepancies of more than 10 % between the measured and the calculated average cross sections for the 24Mg(n,p)24Na, 47Ti(n,p)47Sc, and 64Zn(n,p)64Cu reactions. The tendencies in the calculated-to-measured ratios are similar to those for 235U fission spectrum-averaged cross sections we previously measured.

The measured average cross sections were also applied for the spectrum adjustment of the 233U fission neutrons using the Neutron Unfolding Package Code (NEUPAC). The adjusted spectrum is close to the Watt-type fission spectrum of 233U within the uncertainties of the obtained spectrum, although there exist some fluctuations in the ratio spectrum of the adjusted to the Watt-type.

Author Information

Kobayashi, K
Research Reactor Institute, Kyoto University, Osaka, Japan
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: E10
Pages: 720–726
DOI: 10.1520/STP15168S
ISBN-EB: 978-0-8031-5281-6
ISBN-13: 978-0-8031-1899-7