THE DECAY OF Os185

Abstract

A study of the decay of Os185 with a magnetic beta-ray spectrometer, scintillation counters, and coincidence circuits reveals radiations of the following energies (in Mev.), intensities, and multipolarities: K-shell X-rays (65%), 0.0716 (0.4%, M1 + E2), 0.1255 (2.5%, M1 + E2), 0.1626 (1%, M1), 0.2334(1.4%, E2), 0.5920 (1.1%, E2), 0.6458(80%, E2), 0.7177 (4.1%, M1 + E2), 0.8720 (7.1%, M1 + E2), and 0.8789 (7.5%, M1 + E2). These transitions are interpreted in terms of a decay scheme involving the following levels in Re185: 0(5/2+), 0.1255(7/2+), 0.6458(1/2+), 0.7176(3/2+), 0.872(3/2+), and 0.879(3/2+) Mev.The ratio of L-capture to K-capture considering decay to all levels of Re185 is 0.38 ± 0.07. The ratio of L-capture to K-capture to the 0.872 and 0.879 Mev. levels is 1.04 ± 0.04. This implies that the Os185-Re186 atomic energy difference is 0.985 ± 0.007 Mev. The half-life of Os185 was found to be 93.6 ± 0.5 days.