MEASUREMENT AND RESONANCE ANALYSIS OF NEUTRON TRANSMISSION THROUGH U-238

Neutron transmissions through 0. 076-, 0. 254-, 1. 080-, and 3. 620-cm-thick samples of isotopically enriched **2**3**8U have been measured from 0. 88 to 100. 0 keV using a time-of-flight technique over a path length of 150 m, the ORELA pulsed neutron source, and a 13-mm-thick lithium-glass detector. To obtain resonance parameters, these transmissions from 0. 88 to 4. 00 keV have been simultaneously least-squares shape-fitted with multilevel Breit-Wigner cross-section formalism. In general, large neutron widths are obtained, resulting in an s-wave strength function of (1. 208 plus or minus 0. 045) multiplied by 10** minus **4 over the interval from 0. 0 to 4. 0 keV. An absolute energy scale accurate to 2 parts in 10,000 was established.