Fission Yields of Natural Uranium with Deuterons of 5, 10, and 13.6 Mev: Deuteron Capture and Competition with Stripping

Abstract

Radiochemical determinations of yields in the fission of natural uranium with 5-, 10-, and 13.6-Mev deuterons have been made for 35 mass chains from mass numbers 72 to 159. The total fission cross sections at the three energies were found to be 3.5, 86, and 430 mb, respectively, by integration of the mass-distribution curve. These cross sections include contributions from the fast-neutron background, which is negligible at the two higher energies but which constitutes nearly all of the observed fission at 5 Mev. Although in gross features the yield-mass curves resemble those for other fissile nuclei, some important differences are apparent. The highly asymmetric yields change nearly as rapidly with energy as those of the valley; the deuteron yield curves are the broadest that have been observed at these energies.