Conversion electron measurement in the β^--decay of ¹⁵¹Pr

The beta(-)-decay of Pr-151 produced by the thermal neutron-induced fission of 235 U has been studied using an on-line isotope separator. From an internal-conversion electron measurement with a Si(Li) detector, K-conversion coefficients were obtained for 20 gamma-transitions. Spins and parities of 6 excited levels in Nd-151 were newly determined from the deduced multipolarities: even parities for the 543 and 627 keV levels, odd parities for 250 and 599 keV, (3/2, 5/2)(+) for 685 keV, and (1/2, 3/2)(+) for 880 keV. The level structure was compared with the rotation-vibration coupling Nilsson model.