The beta decay of 2.0×${10}^4$-yr ${\mathrm{Nb}}^{94}$ has been investigated by means of a scintillation spectrometer. The beta spectrum has an end-point energy of 470±6 keV and yields a linear Fermi-Kurie plot when a shape factor of $p^2+\lambda q^2$ $\lambda =1.75\mathrm{}\pm 0.15$ is applied. The shape factor indicates the transition is second-forbidden non-unique, in accord with its $log\mathrm{ft}$ value of 12. Additional measurements were made of electromagnetic radiations from both ${\mathrm{Nb}}^{94}$ decay and that of 6.6-min ${\mathrm{Nb}}^{94m}$ No new transitions were observed, but more precise energy determinations of the gamma rays emitted in the decay of ${\mathrm{Nb}}^{94}$ were obtained. The results of this study further support previously proposed spin and parity assignments.

• Received 26 January 1966

DOI:https://doi.org/10.1103/PhysRev.147.867