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The Slow Neutron Cross Sections of Indium, Gold, Silver, Antimony, Lithium, and Mercury as Measured with a Neutron Beam Spectrometer
Phys. Rev. 70, 154 – Published 1 August, 1946
DOI: https://doi.org/10.1103/PhysRev.70.154
Abstract
The variations of the slow neutron transmissions of In, Au, Ag, Sb, Li, and Hg have been investigated as a function of the time-of-flight of the incident neutrons for a 5.4-meter path by use of a neutron beam spectrometer. A method of analysis is developed for determining and for resonances above 1 ev based on the experimental transmission curves and the Breit-Wigner theory. The positions of the levels located, listed in order of importance for each element, are: In, (1.44±0.04) ev; Au, (4.8±0.2) ev; Ag, (5.11±0.2) ev, (13.7±1) ev, and (43±5) ev; Sb, (6.3±0.5) ev, (19.2±1.0) ev, and indications of other unresolved levels in the region of 50 to 500 ev; Li, only a cross section; Hg, a negative level at (-2.0±0.2 ev) and indications of unresolved positive levels above 25 ev. In the thermal region, the Ag, Sb and Li cross-section curves can be resolved into the sum of a constant term and a term. If is the neutron energy in ev, these are: Ag: /atom; Sb: /atom; Li: /atom; LiF was used in the Li measurements and a value 2.5× /atom has been deducted for the F. The Hg cross section below 5 ev was well matched by the relation /atom.
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