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Huck et al. [5], but they were not able to place it. They suggested that the [5-decay of this isomer feeds lowspin levels of 129Te, which is inconsistent with its feeding from the 11/2-isomer in 129Sn and not the 3/2 + isomer. Presence of a 3-gs isomer in 129Sb has also been suggested [2].We have performed experiments on the A=129 mass chain to address the questions of isomerism in I298b. The experiments were performed using the TRISTAN on-line mass separator at Brookhaven National Laboratory. A high temperature plasma ion source was used to produce the ionized fission products. Mass-separated activity was deposited on an aluminized mylar tape which was moved periodically to the analysis position. Four Ge detectors were used to collect ~/coincidence and gamma multiscaling data. Aproximately 45 million coincidence events were recorded in this experiment. In a second experiment, a single Ge detector and a windowless Si(Li) were used to collect ~,-ray singles and conversion-electron data on the A=129 mass chain.Part of the 129Sb level scheme, populated in the decay of the 11/2-, 129Sn isomer, is shown in Fig. 1. Two levels were identified that are isomeric states: the 1851-and 1861-keV levels. The 723-and 1129-keV transitions are intense transitions in the 129Sb level scheme and are in coincidence with each other, establishing a level at 1851 keV. Gating on III INN

The decay of 148Ce to levels of 148Pr has been studied using mass-separated sources. A half-life of 56 ± 1 s has been measured for the decay of 148Ce. A level scheme containing 40 γ rays and 15 excited levels is proposed for 148Pr. Strongly β-fed 1+ levels have been identified at 390 and 520 keV that are similar in position to 1+ levels observed in isotonic 146La and isotopic 146Pr.

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