In this work microsecond isomers in ${}^{130,132}\mathrm{Te}$ and ${}^{134}\mathrm{Xe}$ are investigated. These nuclei are produced by thermal neutron induced fission of ${}^{239}\mathrm{Pu}$ and ${}^{241}\mathrm{Pu}.$ The detection is based on time correlation between fission fragments selected by the LOHENGRIN spectrometer at ILL (Grenoble) and the $\gamma$ rays or conversion electrons from isomers. The ${10}^{+}\to 8^{+}$ isomeric transition of ${}^{132}\mathrm{Te}$ and ${}^{134}\mathrm{Xe}$ was measured for the first time and the half-life of the analogous transition in ${}^{130}\mathrm{Te}$ was remeasured. The systematic behavior of the $B\left(E2\mathrm{}\right)\mathrm{}$ values of this isomeric transition is studied in Sn, Te, Xe, and Ba isotopes close to ${}^{132}\mathrm{Sn}.$ A simple mechanism is proposed to explain the strong increase in the $B\left(E2\mathrm{}\right)\mathrm{}$ strengths from the Sn to the Te isotones.

• Received 21 December 2000

DOI:https://doi.org/10.1103/PhysRevC.63.054315