Nuclear Shape at High Spin and Excitation Energy

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