Scattered protons from ${}_{}{}^{154}{}_{}{}^{}\mathrm{Eu}$ were measured with an Enge split-pole spectrograph at a bombarding energy of 12 MeV. Rotational states in the ground band of ${}_{}{}^{154}{}_{}{}^{}\mathrm{Eu}$ were excited to $I^{\pi }=8^{-}$. Values of the deformation parameters were extracted from the scattering data using a coupled-channels calculation. The analysis yields ${\beta }_2=0.30\mathrm{}$ and ${\beta }_4=0.04\mathrm{}$. A comparison of the ground band rotational properties of both ${}_{}{}^{152}{}_{}{}^{}\mathrm{Eu}$ and ${}_{}{}^{154}{}_{}{}^{}\mathrm{Eu}$ suggests that both nuclei have the same ground state configuration: ${\pi }_{\frac{5}{2}}\mathrm{}\left[413\right]\mathrm{}$, ${\nu }_{\frac{11}{2}}\mathrm{}\left[505\right]\mathrm{}$.

NUCLEAR REACTIONS ${}_{}{}^{154}{}_{}{}^{}\mathrm{Eu}$ ($p$,$p^{\prime }$), $E_p=12\mathrm{}$ MeV; measured $E_p^{\prime }$ and $\sigma \left(\theta \right)$, split-pole spectrograph; adiabatic coupled-channel analysis; deduced levels, $J^{\pi }$, ${\beta }_2$, and ${\beta }_4$; isotopically enriched radioactive target.

NUCLEAR STRUCTURE ${}_{}{}^{154}{}_{}{}^{}\mathrm{Eu}$, assigned Nilsson configuration.

• Received 7 May 1979

DOI:https://doi.org/10.1103/PhysRevC.20.1279