Additional evidence forββdecay ofTe128

The amounts of excess ${}_{}{}^{128}{}_{}{}^{}\mathrm{Xe}$ and ${}_{}{}^{130}{}_{}{}^{}\mathrm{Xe}$ in xenon which had been extracted by stepwise heating of an old telluride ore from the Mattagami Lake area, Quebec, indicate that the $\beta \beta$-decay half-life of ${}_{}{}^{128}{}_{}{}^{}\mathrm{Xe}$ exceeds that of ${}_{}{}^{130}{}_{}{}^{}\mathrm{Te}$ by a factor of (1.57 ± 0.10) × ${10}^3$. These results agree with the relative half-lives reported earlier for ${}_{}{}^{128}{}_{}{}^{}\mathrm{Te}$ and ${}_{}{}^{130}{}_{}{}^{}\mathrm{Te}$ in tellurides from Kalgoorlie, Western Australia.