Nuclear Shape at High Spin and Excitation Energy

Abstract

High-energy gamma rays from the deexcitation of giant dipole resonance modes have been measured for the decay of $^{108}\mathrm{Sn}^{*}$ and $^{166}\mathrm{Er}^{*}$. The structure of the observed resonances can be correlated with the shapes of these nuclei at high excitation energy (${E}^{*}\ensuremath{\simeq}60$ MeV). For the deformed system $^{166}\mathrm{Er}^{*}$ a shape change with increasing temperature is suggested.