Spectroscopy along flerovium decay chains. III. Details on experiment, analysis, 282Cn, and spontaneous fission branches

Flerovium isotopes (element Z = 114) were produced in the fusion-evaporation reactions 48Ca + 242,244Pu and studied with an upgraded TASISpec decay station placed in the focal plane of the gas-filled separator TASCA at the GSI Helmholtzzentrum fur Schwerionenforschung in Darmstadt, Germany. Twenty-nine flerovium decay chains were identified by means of correlated implantation, alpha decay, and spontaneous fission events. Data analysis aspects and statistical assessments, primarily based on measured rates of various events, which laid the foundation for the comprehensive spectroscopic information on the flerovium decay chains, are presented in detail. Various decay scenarios of an excited state observed in 282Cn are examined in depth with the help of GEANT4 simulations and assessed by predictions of beyond mean-field calculations including triaxial shape degrees of freedom. Previous, revised, and newly derived fission probabilities of even-even superheavy nuclei are compared with various theoretical predictions.

Automated summary

Flerovium isotopes (element Z = 114) have been produced and studied using an upgraded TASISpec decay station in Germany. Through fusion-evaporation reactions and analysis of correlated implantation, alpha decay, and spontaneous fission events, 29 flerovium decay chains were identified. The study provides detailed data analysis and statistical assessments for understanding the spectroscopic information of flerovium decay chains, as well as examining the decay scenarios of an excited state observed in 282Cn.