[en] Recent experiments to synthesize the heaviest elements have dramatically expanded the periodic table and the Segrè chart of nuclides

[en] For the 60 years that have passed after the discovery of the first artificial elements Np and Pu, the investigations of the properties of new elements have become one of the fundamental and quickly developing fields of nuclear physics and nuclear chemistry. The transition from the traditional method of producing transuranium elements, where continuous and pulsed neutron fluxes have been used, to nuclear reactions induced by heavy ions has made it possible to synthesize 12 new elements heavier than fermium (Z=100). The theoretical description of the masses and fission barriers of the new nuclei led in the mid-1960s to the prediction of 'islands of stability' for the very heavy and superheavy nuclides in the vicinity of the closed proton and neutron shells. The experimental data that demonstrate the enhanced stability of nuclei, close to the deformed shells Z=108 and N=162, relative to different decay modes and also the reactions of their synthesis are discussed from the point of view of advancing into an unexplored region of heavier (superheavy) and significantly longer-lived nuclides close to the spherical shells Z=114 and N=184. Experiments are described and first results are presented on the synthesis of superheavy nuclei in ⁴⁸Ca-induced reactions. Presented are also the observed decay chains of individual atoms consisting of sequential α-decays and terminated by spontaneous fission. The energies and half-lives are in agreement with the predictions of theoretical models describing the structure of heavy nuclei. They are considered as a first evidence of the existence of the hypothetical region of stability of superheavy elements. The experiments were carried out at the FLNR heavy ion accelerator in the framework of a large collaboration with LLNL (Livermore), GSI (Darmstadt), RIKEN (Saitama), the Institute of Physics and Department of Physics of the Comenius University (Bratislava) and the Department of Physics of the University in Messina

[en] The state-of-the-art of studies dealing with the synthesis and properties of new superheavy elements is scrutinized. The experiments intended to identify and study the chemical properties of superheavy elements, as well as the facilities used for this purpose, are described. Special attention focuses on the theoretical assessment of the relativistic effects on the properties of these elements. The prospects of these investigations have been considered in the light of the creation of the world's first Factory of Superheavy Elements in Russia.The bibliography includes 48 references. (review)

[en] Nuclear properties of nuclei with a few valence nucleons outside the doubly-magic ¹³²Sn core and located in the octupole correlation region have been investigated via γ-γ-γ coincidence measurements of prompt gamma-ray emitted in the spontaneous fission of ²⁵²Cf with Gammasphere. The high spin level scheme of ¹³⁴I has been identified for the first time. Shell model calculations reproduce the level scheme quite well. The level schemes of ¹³⁷I and ¹³⁹Cs have been reinvestigated and extended. Their nuclear structure is well described by realistic shell model calculations. The g-factors of the 4⁺ state in ¹³⁴Te, 15/2⁺ state in ¹³⁵I, and 15/2^- state in ¹³⁷Xe were determined using a newly developed program for angular correlation analysis. The measured g-factors compared favorably with shell model calculations. Octupole correlations are proposed in ¹⁴¹Cs and ¹⁴²Cs. The variations of D₀ in the Cs isotopes exhibit a pronounced drop of dipole moment with increasing neutron number.