A Measurement of the Fission Cross Section of Plutonium-241 from 8 eV to 70 keV

We have measured the ratio of the ²⁴¹Pu fission cross section to the ⁶Li(n, α) cross section at neutron energies from thermal to 70 keV. The Lawrence Livermore Laboratory electron Linac provided a pulsed source of neutrons, and energies were measured by time-of-flight. The evaluated ⁶Li cross section was used to obtain σ(n, f) for ²⁴¹Pu from 8 eV to 70 keV and to normalize the results to the accepted thermal fission cross-section value.