Nuclear-Resonance Fluorescence inXe130

The 536-keV ($2^{+}$) first excited state of ${\mathrm{Xe}}^{130}$ has been investigated by means of nuclear-resonance-fluorescence scattering experiments. The use of a Ge(Li) detector allowed a good determination of the Rayleigh scattering contribution which amounted to about 30% of the resonant peak. The level width was found to be (5.2 ± 0.9) × ${10}^{-5\mathrm{}}$ eV, corresponding to a mean life of (1.3 ± 0.3) × ${10}^{-11\mathrm{}}$ sec and a ${B\left(E2\mathrm{}\right)\mathrm{}}_{\uparrow }$ of $(0.69\mathrm{}\pm 0.15)e^2\times {10}^{-48\mathrm{}}$ ${\mathrm{cm}}^4$. From this result and the relative transition probabilities determined previously in a Coulomb-excitation experiment by Pieper, Anderson, and Heydenburg, the absolute $B\left(E2\mathrm{}\right)\mathrm{}$ values for the first excited states of ${\mathrm{Xe}}^{128}$ and ${\mathrm{Xe}}^{132}$ were obtained.