(EC+beta(+)) decay study of Ce-128

The (ECI-beta(+)) decay of Ce-128 was reinvestigated in the Sn-116 (O-16, 4n) reaction by using a helium-jet tape transport system. The close half-lives of Ce-128 and Ce-129 made it difficult to separate the decay gamma rays of both nuclei apart. Instead of the excitation-function measurements, both reactions of O-16+Sn-116 and O-16+Sn-117 were carried out, and from their comparisons, the decay gamma rays of Ce-128 were clearly told from those of Ce-129. Based on X-gamma and gamma-gamma coincidence measurements, a detailed (EC+beta(+)) decay scheme of Ce-128 has been proposed, which revises the previous one.