N=90 Region: The Decay Of Eu-154 To Gd-154

The decay of Eu-154-->Gd-154 has been studied by gamma-ray singles and gamma-gamma coincidence spectroscopy using an array of 20 Compton-suppressed Ge detectors. The primary goal of the work was to investigate the structure of Gd-154 above 1 MeV: The outcome is the removal of 11 levels from the previously adopted Eu-154 decay scheme, the addition of 40 new gamma-ray assignments, and upper limits set on 75 gamma-ray transitions which had been previously assigned to the Gd-154 level scheme. The current results, combined with data from other spectroscopic techniques, indicate that states which were previously interpreted as "two-phonon" excitations are either spurious or are shown to be of a different nature. These results provide a deeper understanding of the structure of Gd-154 and the N=90 isotones.