THE DECAY OF Pm151

Abstract

The radiations from Pm151 have been studied by external and internal conversion measurements and electron–electron, electron–beta, electron–gamma, and beta–gamma coincidence experiments. Thirty-six transitions have been identified. A decay scheme incorporating 30 of these has been established by energy and coincidence measurements with levels in Sm151 at 0, 0.0048, 0.0658, 0.0697, 0.0915, 0.1048, 0.1677, 0.1684, 0.2090, 0.3239, 0.3449, 0.4445, 0.741, and 0.821 Mev. The half-life of the 0.0048-Mev level is (19 ± 10) × 10−9 sec. The total decay energy is 1.195 ± 0.010 Mev.