"The discovery of the superheavy elements and of the stability island of the nuclide's map"

 

 

 

SPEAKER:  Prof. Yuri Oganessian

(Flerov Laboratory of Nuclear Reactions, JINR Dubna)

 

MODERATOR:  Prof. Emanuele Vardaci

 

 

 

ISTITUTIONAL GREETINGS

 

   - Prof. Leonardo Merola,

      Direttore del Dipartimento di Fisica "E. Pancini"

 

   - Prof. Giovanni La Rana,

      Direttore della Sezione INFN di Napoli

 

 

In questo seminario si discuterà della scoperta degli elementi dal Flerovium (Fl, Z=114) all'Oganesson (Og, Z=118) e dell'isola di stabilita' della mappa dei nuclidi nella regione a Z=114 e N=184.

 

 

Abstract

A fundamental outcome of modern nuclear structure microscopic theory is the prediction of the ‘islands of stability' in the region of hypothetical superheavy elements (SHEs). In a heavy nucleus, going through the large-scale deformation on the way to fission, the motion of single nucleons is coupled with the collective degrees of freedom of the whole system.

 

The most striking effect of this coupling is obtained for the case of fission of the heaviest nuclei, whose existence is defined entirely by the nuclear structure, i.e. by the shell effect. From this point of view, the synthesis and study of properties of superheavy nuclei (SHN) is a direct way for checking the basic statements of the microscopic nuclear theory. On the nuclide's map, SHN outline the border of the heaviest nuclear masses. SHN set the limits of the periodic system of chemical elements.

 

The study of possible existence of SHN in nature offers a way for testing different scenarios of astrophysical nucleosynthesis. The seminar presents results concerning the discovery of the ‘stability island' of SHEs and in particular the discovery of the elements from Flerovium (Fl, Z=114) to Oganesson (Og, Z=118).