The energies of the three gamma rays in cascade with the ${\beta }^{-}$ emission of ${\mathrm{Lu}}^{176}$ have been determined to be 306, 203, and 89 kev. Peak intensity and conversion x-rays suggest the assignment of all transitions as $E2\mathrm{}$. The energies support the theory of Bohr and Mottelson. The total $K$ x-ray intensity shows no excess to be ascribed to a $K$-capture branch setting a limit of $\frac{K}{{\beta }^{-}}<0.1\mathrm{}$. The half-life of ${\mathrm{Lu}}^{176}$ is (2.15±0.10)×${10}^{10}$ years.

• Received 5 November 1953

DOI:https://doi.org/10.1103/PhysRev.93.743