Energy levels in La-139 from the decay of Ba-139

The gamma -ray spectrum of La-139 following the beta (-) decay of Ba-139 ha s been studied using both singles and yy coincidence spectroscopy technique s. The energies and intensities of 30 gamma -transitions have been deter-mi ned, which include three new transitions placed in the level scheme. Two ne w levels at 1524.6 and 1900.3 keV excitation energies are proposed and a nu mber of gamma -transitions have been confirmed. On the basis of these resul ts a precise decay scheme is proposed. (C) 2001 Elsevier Science Ltd. All r ights reserved.