ELECTRIC MONOPOLE TRANSITIONS OBSERVED IN 154GD FOLLOWING BETA-DECAY OF 154EU

The K-conversion electron intensities of transitions in 154Gd with strong E0 components have been measured at 0.1% resolution in momentum. Transitions of 692.41, 680.70 and 676.58 keV are observed from the 0+, 2+ and 4+ members of the β-vibrational band to levels with the same spin in the ground state band. The previously reported transition of 533.6 keV is found to be a doublet of 533.04 and 535.06 keV. Both these transitions have a large E0 component and are tentatively assigned as being between the levels of spin 2+ and 3+ of a second K = 2 band and the corresponding 2+ and 3+ levels of the K = 2 γ-vibrational band. It is suggested that the upper K = 2 band be interpreted as a β-vibrational band built on the γ-vibrational band. © 1969.