THE DECAY OF Er171

Abstract

The decay of Er¹⁷¹ has been studied with a magnetic beta-ray spectrometer at a resolution of 0.5%. The energies and intensities of 30 transitions in Tin¹⁷¹ have been established. The energies (Mev) and intensities (%) are as follows: 0.086 (~0.1), 0.1117 (68.8), 0.1166 (6.05), 0.1240 (20.5), 0.1664 (0.65), 0.2104 (0.67), 0.2364 (0.57), 0.2770 (0.74), 0.2956 (28.7), 0.3082 (64.4), 0.3712 (~0.4), 0.4040 (0.03), 0.4189 (0.09), 0.5437 (0.04), 0.5571 (0.08), 0.5727 (0.07), 0.6061 (0.10), 0.6187 (0.13), 0.6703 (0.30), 0.6753 (0.39), 0.7321 (0.18), 0.738 (0.06), 0.7835 (0.31), 0.7962 (0.80), 0.842 (0.04), 0.869 (0.06), 0.882 (0.07), 0.906 (0.88), 0.9105 (0.25), 0.962 (0.11). These transitions are interpreted in terms of 12 levels whose energies and spins are: 0 (1/2+), 0.0051 (3/2+), 0.1167 (5/2+), 0.1291 (7/2+), 0.4251 (7/2−), 0.5915 (9/2−), 0.6355 (7/2+), 0.675(3/2+), 0.737 (5/2+), 0.912 (5/2+), 0.963 (5/2+), 0.997 (7/2+). The decay energy of Er¹⁷¹ is 1.490±0.002 Mev.