The nuclear structure of 151Pm in the low excitation region < 1 MeV

Abstract

The level scheme of 151Pm populated by the β-decay of 12 min 151Nd has been studied using Ge(Li) detectors as singles and coincidence γ-ray spectrometers. Most of the new γ-rays have been included in a partial level scheme of 151Pm involving four new levels. Angular correlation measurements on the 170.752–255.678 keV and 170.752–138.882 keV cascades have been made with the result A 2 = 0.088±0.005 and −0.02 – +0.05, respectively. A PAC measurement on the 170.752–255.678 keV cascade has yielded the g-factor of the 255.676 keV level as g = 1.18 ±0.16. A Nilsson-model calculation including Coriolis coupling has been made and the experimental level energies have been well reproduced by the Nilsson orbitais [413]↓, [411]↑, [420]↑, [532]↑, [541]↑ and [550]↑. Theoretical transition rates, E2/M1 mixing ratios, branching ratios and g-factors are in good agreement with experimental values.