Investigations ofI128

The ${\beta }^{-}$, $\gamma$ and electron capture processes of ${\mathrm{I}}^{128}$ were investigated with the solenoidal magnetic spectrometer, a single-channel scintillation spectrometer, a multiple-channel selective coincidence scintillation spectrometer, and a proportional counter spectrometer. Three ${\beta }^{-}$ groups with energies 2.120, 1.665, and 1.125 Mev and relative abundance 76.0:15.5:2.0, and four $\gamma$ radiations with energies 0.455, 0.540, 0.750, and 0.990 Mev and relative intensities 100:9.7:1.7:1.8 were found. The electron capture branch was determined to be 6.4% of the total disintegration. The ratio of electron capture to the ground to that to the first excited state of ${\mathrm{Te}}^{128}$ is 19:1. Spin and parity were assigned to the ground and excited states of the daughter nuclei ${\mathrm{Te}}^{128}$ and ${\mathrm{Xe}}^{128}$, and a decay scheme was proposed for ${\mathrm{I}}^{128}$.