Studies of the N=90 region: The decay of 154Eu to 154Gd

The decay of {sup 154}Eu {yields} {sup 154}Gd 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 confirm or refute a large number of questionable features in the decay scheme: the outcome is the removal of 8 levels from the previously adopted scheme, with the result that a new type of collective band is revealed. Many weak decay branches for the decay are clarified. These results are critical for understanding the structure of {sup 154}Gd and the N = 90 isotones; and the improved completeness of the decay scheme contributes to the use of {sup 154}Eu as a metrological standard