QUANTUM CHOAS AND ROTATIONAL DAMPING

The appearence of quantum chaos in the excited rapidly rotating nucleus is studied in a simple nuclear model, consisting of the cranked Nilsson model with a schematic two-body interaction added. Chaos is found to smoothly set in at a much lower excitation energy in normal-deformed Yb-168 than in superdeformed Dy152. A dynamical sign of chaos is a saturation of the standard deviation of the E2-strength function, and also the disapearence of correlations in gamma-gamma-correlations. Motional narrowing may however restore the correlations also for the completely chaotic case. The distribution of E2-matrix elements strongly deviate from Porter-Thomas result, and many more strong gamma-transitions appear than expected from GOE-theory. Transition entropy is introduced as a measure of order in the E2 cascade.