HALF-LIFE MEASUREMENTS AND TRANSITION PROBABILITIES IN 172YB

The half-lives of the 78.7 keV, 1172 keV and the 1263 keV states of 172Yb populated in the decay of 172Lu(6.7 d) were measured by the delayed coincidence method to be 1.58±0.06 nsec, 8.14±0.220 nsec and 0.49±0.03 nsec, respectively. The energy selection was improved by using either a magnetic spectrometer or a triple coincidence arrangement. Transition rates were calculated using experimental gamma-ray intensities and theoretical internal conversion coefficients. The electric quadrupole moment for the rotational band at 1172 keV was found from the 91 keV transition probability to be Q0 = 7.5±0.5 b. The transition probabilities for K-forbidden transitions from the K = 3 band based at 1172 keV to the ground state band are discussed in terms of the Bohr-Mottelson and Mikhailov predictions. © 1969.