Seminarium Fizyki Jądra Atomowego

One of the fundamental outcomes of the nuclear shell model is the prediction of the “stability islands” in the domain of the hypothetical super heavy elements. The enhanced stability has been expected for the deformed nuclei near Z=108 and N=162, yet much stronger effect has been predicted for heavier spherical nuclei close to the shells Z=114 and N=184, next to the doubly-magic nucleus 208Pb (Z=82, N=126). The talk is devoted to the experimental verification of these predictions – the synthesis and study of both the decay and chemical properties of the super heavy elements.For the synthesis of the heavy nuclei fusion reactions of the nuclei of 208Pb, 209Bi with the projectiles of 50Ti, 54Cr, 70Zn (cold fusion) have been used, which allowed to investigate decay properties of the nuclides with Z=104-113 and N=151-165 in the region of the deformed shells Z=108 and N=162. The synthesis of even heavier and more neutron-rich nuclei has been carried out in the fusion reactions of 233,238U, 237Np, 242,244Pu, 245,248Cm, 249Bk and 249Cf with the 48Ca projectiles (hot fusion), that made it possible to study decay of the 52 neutron-rich nuclides with Z=104-118 and N=161-177. The decay properties of the new isotopes present direct experimental evidence of the existence of the Island of stability in the region super heavy nuclei that considerably expand the Periodical Table of the chemical elements. Simultaneously in the chemical studies of elements 112-114 by methods of absorption gas chromatography the influence of the “relativistic effect” on the chemical properties of the super heavy elements was obtained for the first time. Further progress of SHE research is related to the studies of nuclear and atomic structure of super heavy elements, fission modes of the neutron-rich nuclides with Z≥104, as well as the synthesis of the new elements and isotopes in close proximity to the magic numbers protons and neutrons. It is directly associated with new facility – the Factory of SHE- based on new high-currant heavy ion accelerator, new setups and more sophisticated detectors. New experimental potentialities will be presented also.In the talk are used the results obtained in FLNR (JINR, Dubna) in collaboration with LLNL, (Livermore, USA), ORNL (Oak-Ridge, USA), and Vanderbilt University (Nashville, USA), Texas A&M University (College Station, USA) as well as GSI (Darmstadt, Germany), PSI (Villigen, Switzerland) and RIKEN (Tokyo, Japan).
Seminarium dodatkowe.