Observation of Superdeformation in ${}_{}{}^{152}{}_{}{}^{}\mathrm{Dy}$

High-resolution, low-background, two-dimensional $\gamma$-ray energy correlations $E\left({\gamma }_1\right)$ vs $E\left({\gamma }_2\right)$ have been measured at high spin in ${}_{}{}^{152}{}_{}{}^{}\mathrm{Dy}$ with the spectrometer TESSA2. Ridges characteristic of rotational behavior are observed for $\gamma$-ray energies $0.8<~E\left(\gamma \right)<~1.35$ MeV. The separation of the ridges gives a dynamical moment of inertai ${{\mathcal{I}}_{\mathrm{band}}}^{\mathrm{}\left(2\right)\mathrm{}}=(85\mathrm{}\pm 2){\hslash }^2$ Me${\mathrm{V}}^{-1\mathrm{}}$ indicating a quadrupole deformation of $\epsilon \approx 0.51$ for a rigid body assuming $\gamma =0\mathrm{}$.