The 11/2-[505] neutron extruder orbital in 159Sm
Résumé
Excited states in 159Sm, populated following the spontaneous fission of 252Cf have been studied by means of gamma spectroscopy, using the Gammasphere array. In 159Sm we have identified an isomeric level with a half-life of T1/2=116(8) ns at an excitation energy of 1276.8 keV and observed a rotational band on top of this isomer. On the basis of the observed properties of the isomer and the band on top of it we propose that the 1276.8-keV level in 159Sm corresponds to the 11/2-[505] neutron extruder configuration. The new excitation scheme of 159Sm is compared to quasiparticle rotor model calculations.