Neutron Total and Absorption Cross Sections of ²³⁸Pu

The neutron total cross section of ²³⁸Pu has been measured from 0.008 to 6500 eV. These data give single-level Breit-Wigner parameters for resonances below 200 eV. The observed total cross section at 2200 m/sec is 588 b. A value of 532 b has been calculated for the effective (equivalent l/v) thermal absorption cross section. Parameters of individual resonances below 200 eV and average parameters at higher energies give a resonance absorption integral of 164 ± 15 b, and a value of (1.10 ± 0.20) × 10^-4 for the s-wave neutron strength function (/D).