RESPONSES OF C6D6 AND C6F6 GAMMA-RAY DETECTORS AND THE CAPTURE IN THE 1.15-KEV RESONANCE OF 56Fe
Engineering Physics and Mathematics Division
Oak Ridge National Laboratory
P.O. Box 2008
Oak Ridge, Tennessee 37831-6356 USA
We have used the electron gamma-ray transport code EGS to calculate responses of C6D6 and C6F6 gamma-ray detectors, where the geometry of the capture experiments was carefully modelled. Very good agreement was obtained with spectra from selected resonances in the capture of neutrons by 207Pb. Weighting functions based upon the calculated responses were used in measuring the capture in the 1.15-keV resonance of 56Fe relative to the capture in the Au 4.9-eV resonance. The neutron width was measured to be 64.5 ± 3. meV with C6F6 detectors, and 63.0 ± 2.5 meV with C6D6 detectors. These values are in good agreement with the value of 61.7 ± 0.9 meV found from transmission measurements.
KEYWORDS: 56Fe, resonance capture