Total Neutron Cross Sections of Uranium-235, Uranium-238, and Plutonium-239 from 0.5 to 15 MeV

The total neutron cross sections of ²³⁵U, ²³⁸U, and ²³⁹Pu were measured over the energy range 0.5 to 15 MeV, using the U.S. National Bureau of Standards electron linear accelerator as a pulsed neutron source. Neutron energies were measured by the time-of-flight method, with a resolution of 0.1 nsec/m. The measurement accuracy is estimated to be ±1%. The cross-section curve is smooth, with no observable fine structure. The data are in excellent agreement with recent results from the Rensselaer Polytechnic Institute, and in satisfactory agreement with the ENDF/B-III data file, except at the high and low energy ends of our energy range.