Low-energy level structure of Sm151 by neutron capture reactions and theoretical interpretation

A nuclear structure study of Sm151 is presented on the basis of low-energy -ray and conversion electron spectroscopy, in connection with thermal neutron capture, and high-energy primary -ray measurements following average resonance neutron capture. The level scheme is established up to 1020 keV and incorporates 44 levels. Unique spin and parity assignments are made for 34 levels, and narrow limits are set for the remaining levels. Further possible levels are given between 355 and 1220 keV. Theoretical calculations are presented in the framework of the quasiparticle-rotor model, introducing Coriolis coupling and N=2 interaction. Comparisons between theoretical and experimental results are made for level energies, branching ratios, and multipole mixing ratios.