Low-Energy Neutron Resonances inSm149

The total neutron cross section of ${\mathrm{Sm}}^{149}$ has been measured in the energy range from 0.06 to ∼20 ev using a crystal spectrometer with resolution 0.17 μsec/meter. The Breit-Wigner parameters have been obtained for four of the larger resonances at energies of 0.0976±0.0005, 0.870±0.003, 4.93±0.03, and 8.9±0.1 ev. The radiation widths for these four resonances are, respectively, in units of ${10}^{-3\mathrm{}}$ ev: 63.6±1.0, 59.8±1.0, 66.7±3.0, and 66.6±6.0. Other resonances were found at energies of 6.4±0.1, 12.0±0.5, 14.8±0.5, and 17.0±0.5 ev.