Abstract
New neutron-rich isotopes of several rare-earth elements have been identified using on-line mass separation. The observed decay rates of K x rays in the mass separated fractions for which 153≤A≤162, together with the associated γ-decay spectra, provided direct isotopic identifications. New isotopes observed, with values of their half lives given in parentheses, are (4.3±0.2 s), (8.9±0.2 s), (5.47±0.11 s), (10.90±0.20 s), (4.8±0.5 s), and (10.6±1.0 s). In addition, we have confirmed recent reports of the observation of (28.9±0.4 s), (25.9±0.2 s), (26.70±0.10 s), (11.37±0.15 s), and (9.6±0.3 s). These half-life values are compared to the reuslts of theoretical predictions.
- Received 17 February 1987
DOI:https://doi.org/10.1103/PhysRevC.35.1965
©1987 American Physical Society