Spectroscopy along Flerovium Decay Chains: Fine Structure in odd-A 289Fl
Annotatsiya
Fifteen correlated α-decay chains starting from the odd-A superheavy nucleus 289Fl were observed following the fusion-evaporation reaction 48Ca+244Pu. The global data set for this isotope was roughly doubled. The nuclear spectroscopy experiment used an upgraded TASISpec decay station placed behind the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. Corroborated by Geant4 simulations, the results call for at least two parallel α-decay sequences starting from at least two different states of 289Fl. Supported by observed α-electron and α-photon coincidences, α-decay fine structure can also be established along the 289Fl chain, namely for the α decays of 285Cn and 281Ds: Two chains concluded by fast fission of Hs, thereby confirming one earlier event. The proposed decay schemes along the 289Fl chain are discussed with nuclear structure models.