Fission Cross-Section Measurements of the Odd-Odd Isotopes ²³²Pa, ²³⁸Np, and ²³⁶Np

Transmutation of actinide waste into fission products could be enhanced by using resonance fission of odd-odd target materials; those of interest are ²³²Pa, ²³⁸Np, and ²⁴²Am. Fission cross-section measurements of two of these short-lived materials were performed at Los Alamos National Laboratory. Samples were produced by the (d,2n) reaction in the Los Alamos Ion Beam Facility followed by fast radiochemistry to separate the odd-odd target of interest. The fission cross section of the nanogram samples was measured in a high intensity pulsed neutron beam produced by 800-MeVproton spallation. Using this procedure, the fission cross sections of the 1.3-day ²³²Pa and 2.1-day ²³⁸Np were successfully measured in the energy range from 0.01 eV to 50 keV. The fission cross section of the relatively long-life isotope ^2S6Np was also measured in the same system while the short half-life isotopes were being prepared. The results and resonance analysis are presented.