A finite number of regular rotational bands in the superdeformed well of 143Eu

The number of excited superdeformed bands in 143Eu is measured by use of the Fluctuation Analysis Method. Between 10 and 40 rotational bands, displaying typical rotational energy correlations over two consecutive transitions, are populated within a rather narrow range in transition energy, Eγ ≈ 1300-1500 keV. These numbers are close to the values found for normally deformed nuclei and agree with microscopic cranking + band mixing calculations for the specific superdeformed nucleus, which predict the onset of rotational damping to occur at the excitation energy U0 = 1.3-1.6 MeV above the yrast line.