We report experimental measurements in ${}^{241}\mathrm{Pu}$ of the following: primary and secondary $\gamma$ rays and conversion electrons from thermal neutron capture in ${}^{240}\mathrm{Pu};\gamma$ rays from ${}^{245}\mathrm{Cm}$ α decay; proton and triton spectra, respectively, from $\mathrm{}(d,p)\mathrm{}$ and $\mathrm{}(d,t)\mathrm{}$ reactions on ${}^{240}\mathrm{Pu}$ and ${}^{242}\mathrm{Pu}$ targets. From these data and those of other investigations, we have identified 53 excited levels in ${}^{241}\mathrm{Pu}$ below 1400 keV. Of these, 44 are placed in 10 rotational bands (with connecting transitions) that have been assigned Nilsson configurations. For the bands below 1 MeV in ${}^{241}\mathrm{Pu}$ that are largely of single-particle character, there is good correspondence with similar bands in ${}^{239}\mathrm{U}$ and with the theoretical model of Gareev et al. For those bands in ${}^{241}\mathrm{Pu}$ where there is mixing between single-particle and vibrational modes, we find some significant deviations from theoretical predictions. For example, the $\frac{5}{2}\left[622\right]\otimes 0^{-}$ state at 519 keV appears to mix less with other states than predicted, while a trio of $K^{\pi }={\frac{1}{2}}^{-}$ bands show unexpected mixing patterns.

• Received 30 September 1997

DOI:https://doi.org/10.1103/PhysRevC.57.1112