The decay of ${\mathrm{Nb}}^{95}$ was investigated in order to check on the unusually short comparative half-life which had been reported for the twice-forbidden ground state to ground state beta transition. It was found that the 0.924-MeV beta group has an abundance of only 0.075% rather than the 1 or 2% reported previously. As a consequence, $log\mathrm{ft}\ge 10.8$ rather than 9.7. The main decay is by a 159.7±0.5-keV beta transition followed by a 764.5±0.5-keV gamma ray. The gamma transition appears to be $E2\mathrm{}$ with a $\frac{K}{\mathrm{}(L+M)\mathrm{}}$ internal conversion ratio of 7.5±0.1 and ${\alpha }_K=(1.1\mathrm{}\pm 0.1)\times {10}^{-3\mathrm{}}$. No evidence was found for an additional 752-keV gamma transition.

• Received 27 May 1963

DOI:https://doi.org/10.1103/PhysRev.132.324