Shifting the closed proton shell to Z = 122 : a possible scenario to understand the production of superheavy elements Z = 112118
P. Ambruster (GSIDarmstadt)
What 


When 
20080925 from 11:00 am à 12:00 pm 
Where  salle des séminaires du GANIL 
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The recent experiments at FLNR, Dubna, demonstrated that crosssections to produce SHEs by
48Cainduced reactions on actinide targets increase beyond Z = 111, reach a maximum of 5 pb at Z = 114
and fall below the 1 pb level at Z = 118. A scenario is proposed to understand the findings within the
frame of former experimental results of heavyelement production and theoretical predictions about the
stability of the nuclides concerned. New ingredients introduced are: 1) to shift the next proton shell beyond
Pb from Z = 114 to Z = 122; 2) the isotopes of the elements Z = 112 to Z = 118 are deformed and their
nuclei have oblate shapes; 3) the fission barriers around the next nucleus with doubly closed shells
N=184 and Z= 122 are larger than the neutron separation energies and reach values in the range of 10MeV.
The ascent of the flat top at N=184 and Z= 122 is described by the proposed scenario,
which likewise excludes reaching the doubly closed shell region at the top by today’s experimental methods.