Abstract
The decay of Ba9256148 to levels of odd-odd La9157148 has been studied in experiments where -ray singles, time-dependent -ray spectra, and t coincidence spectra were collected. The Ba148 activity was produced directly by on-line mass separation. The half-life of Ba148 was determined to be 0.610.03 s. A level scheme containing 26 levels and 63 rays is proposed for La148. Spin and parity for several low-lying levels are assigned on the basis of internal conversion coefficient measurements and - and -ray branching. A half-life of 674 ns is measured for the 56-keV level. Several features of the level scheme are discussed and compared to neighboring La isotopes and N=91 isotones. [RADIOACTIVITY Ba148 [from U235(nth,f)] measured E,I,k,t12,t coincidence, LEPS and HpGe detectors; La148 deduced levels, I,J, and level halflife. Mass separated Ba148 activity.] © 1984 The American Physical Society.