Long-Lived Tellurium Isomers

Abstract

The internal conversion electron spectra of neutron-activated enriched tellurium isotopes have been studied. It has been shown that each odd mass-number isotope from 121 to 131 exists in a long-lived isomeric state. In all cases the initial isomeric transition is $2^4$-pole magnetic, which appears to identify the long-lived isomeric states with a spin of 11/2. The spins of the ground states of ${\mathrm{Te}}^{127}$, ${\mathrm{Te}}^{129}$, ${\mathrm{Te}}^{131}$ would appear to be 3/2, and that of ${\mathrm{Te}}^{123}$ 1/2. Information about ${\mathrm{Te}}^{121}$ and ${\mathrm{Te}}^{125}$ ground states is incomplete.