Beta Decay ofTb161

The radiations emitted in the beta decay of 7-day ${\mathrm{Tb}}^{161}$ have been studied with a 180°, 40-cm radius of curvature, shaped magnetic field spectrometer and a scintillation counter. Gamma-gamma coincidence measurements have also been made. The following transitions with multipolarities indicated were observed (energies in kev): $25.5\left(E1\mathrm{}\right)\mathrm{}$, $48.9\left(M1\mathrm{}\right)\mathrm{}$, $56.9(E1, \mathrm{tentative})$, and $74.6\left(E1\mathrm{}\right)\mathrm{}$. The following beta groups were also observed (energies in kev): 571, 522, 496, and 439. A level scheme incorporating these data is presented.