HIGH ENERGY RESOLUTION MEASUREMENT OF THE 238U NEUTRON CAPTURE YIELD IN THE ENERGY REGION BETWEEN 1 AND 100 keV


Roger L. Macklin#, R.B. Perez#, G. de Saussure, and R.W. Ingle

Engineering Physics and Mathematics Division
Oak Ridge National Laboratory
P.O. Box 2008, Oak Ridge, Tennessee 37831-6354 USA
#Nuclear Engineering Department, The University of Tennessee, Knoxville, Tennessee USA


A measurement of the 238U neutron capture yield was performed at the 150-meter flight-path of the ORELA facility on two 238U samples (0.0124 and 0.0031 atoms/barn). The capture yield data were normalized by Moxon's small resonance method.

The energy resolution achieved in this measurement frequently resulted in doublet and triplet split-tings of what appeared to be single resonances in previous measurements. This resolution should allow extension of the resolved resonance energy region in 238U from the present 4-keV limit up to 15 or 20 keV incident neutron energy.

Some 200 small resonances of the (238U + n) compound nucleus have been observed which had not been detected in transmission measurements, in the energy range from 250 eV to 10 keV.

KEYWORDS: 238U, Neutron Capture Yield 1 keV < E < 100 keV