Measurement of the Neutron-Induced Fission Cross Section of ²³²Th Relative to ²³⁵U from 0.7 to 30 MeV

We have measured the fission cross-section ratio ²³²Th:²³⁵U as a function of neutron energy from 0.7 to 30 MeV using ionization fission chambers, the threshold cross-section method, and the time-of-flight technique at the Lawrence Livermore National Laboratory 100-MeV electron linear accelerator. The measured cross-section ratio, averaged over the neutron energy interval from 1.75 to 4.00 MeV, was 0.1086 ± 0.0024.