Lifetime of the 603-keV Level ofTe124

A modified centrifuge technique using a rotating scatterer in addition to a rotating source has been used to measure the lifetime of the 603-keV level of ${\mathrm{Te}}^{124}$. This method yields a considerable improvement of the overlap of emission and absorption lines compared with a single-rotor arrangement if $\gamma$ rays from a ${\mathrm{Sb}}^{124}$ source are used to excite the 603-keV level in ${\mathrm{Te}}^{124}$. In order to check the reliability of this method, a single-rotor lifetime measurement was also carried out, the result of which agreed very well with the result of the double-rotor measurement. The weighted average of both values for the mean lifetime of the 603-keV level in ${\mathrm{Te}}^{124}$ is $\tau =(9.5\mathrm{}\pm 0.5)\times {10}^{-12\mathrm{}}$ sec.