Search for two-phonon vibrations inEr168

Abstract

The low-lying level structure of ${}_{}{}^{168}{}_{}{}^{}\mathrm{Er}$ has been examined by the (n, ${\mathrm{n}}^{\prime }\gamma$) reaction and all known levels with $J<\mathrm{}7\mathrm{}$ and $E_x<~2.0$ MeV are observed. The discovery of a level at 1893 keV calls for a reexamination of the completeness of the level scheme assumed previously for this nucleus. No new low-lying candidates for two-phonon $\gamma$ vibrations are observed.