Disintegration Schemes of theTe127andTe129Ground States

Abstract

A coincidence scintillation spectrometer was used to study the decay of the 9.3-hour ${\mathrm{Te}}^{127}$ isomer and the 72-minute ${\mathrm{Te}}^{129}$ isomer. The ${\mathrm{Te}}^{127}$ isomer was found to decay by a simple beta ray with an end-point energy of 0.683±0.010 Mev. The beta-ray spectrum of the ${\mathrm{Te}}^{129}$ isomer consists of two beta groups with end-point energies of 1.46±0.01 and 1.01±0.02 Mev. Two gamma rays with energies of 0.450±0.005 and 0.035 Mev were observed, and they were found to be in coincidence. The 0.450-Mev gamma ray was shown to be in coincidence with the 1.01-Mev beta ray, and the 0.035-Mev gamma ray was shown to be in coincidence with the 1.46-Mev beta ray. The results are consistent with level assignments based on the shell model of the nucleus.