The decay of 150Eu(12.8 h)

Abstract

The γ-ray spectrum of 150 Eu (12.8 h) has been studied using a 7 mm × 4 cm 2 Ge(Li) detector to obtain more precise values for the energy levels and transition intensities in 150 Sm. The new values for the energies of previously reported transitions are 333.9, 406.5, 620.3, 712.2, 831.8, 917.7, 921.7, 1165.7, 1223.0, 1629.4 and 1963.0 keV; in addition, new transitions of 209.4, 305.4, 425.3, 860.1, 1046.2, 1193.7 and 1452.3 keV have been observed. Branching ratios for E1 and E2 transitions de-exciting higher-lying states were obtained. A revised decay scheme is presented and discussed. The half-life of the long-lived 150 Eu isomer has been measured to be 6.2±0.5 y.