Ba134level scheme as observed in the decay ofLa

Abstract

The level scheme of even-even '"Ba has been studied from the decay of the '"Ce (75.9 h) t'"La (6.67 min) chain. Samples of '"Ce were produced by -800-MeV proton bombardment of Pr foils, followed by chemical and mass separation. y-ray energy and intensity measurements were made using Ge(Li) and Si(Li) detectors.Identification of y rays as belonging to the '"La decay was made in separate experiments using sources of ' 'La milked from the parent '"Ce activity. In this manner, -99 y-ray transitions have been associated with the '"La decay scheme. From these data and y-y coincidence measurements, a comprehensive level scheme is proposed for '"Ba, consisting of -41 excited states. Further information on the energies of levels in " Ba was derived from a subsidiary series of y-ray energy measurements using a source of ' Cs. For the '"La decay, logft values were obtained from relative x-ray, annihilation-quanta, and y-ray intensities and using intensitybalance considerations for the individual levels in ' Ba. A comparison is made of the ' Ba data with the predictions of several recent theoretical calculations dealing with even-even nuclei in this mass region.

MultiparticleM1band inLa134

“…The signature splitting and inversion are also important phenomena observed in doubly odd nuclei [6]. Originally, the nucleus 134 La was studied in the decay of 134 Ce [7]. Two partial level schemes were established by Morek et al [8].…”