Neutron Total Cross Section of Curium-248

The neutron total cross section for ²⁴⁸Cm has been measured from 0.5 to 3000 eV using the Oak Ridge electron linear accelerator (ORELA) as a pulsed neutron source. The cylindrical samples of small diameter (1.6 to 4.0 mm) contained up to 13 mg of 97% ²⁴⁸Cm and 3% ²⁴⁶Cm in the oxide form. Samples were cooled with liquid nitrogen to reduce Doppler broadening. The thickest sample had an inverse thickness for curium isotopes of 624 b/atom, which made possible the identification of forty-seven resonances attributable to ²⁴⁸Cm and five resonances attributable to ²⁴⁶Cm. The cross-section data have been analyzed to obtain single-level Breit-Wigner resonance parameters for all observed resonances. An average level spacing of 40 ± 5 eV and an average s-wave neutron strength function of (1.2 ± 0.2) × 10-⁴ were determined for ²⁴⁸Cm. The resonance contributions to the thermal capture cross sections and the resonance integrals determined from the resonance parameters are ²⁴⁸Cm, = 2.51 ± 0.26 b, I_nγ = 259 ± 12 b; ²⁴⁶Cm, = 1.2 ± 0.4 b, I_nγ = 101 ± 11 b. These values compare well with the results of integral measurements.