The importance of closed shell structures in the synthesis of super heavy elements

11th International Spring Seminar on Nuclear Physics: Shell Model and Nuclear Structure – achievements of the past two decades

Hamilton, J.H.^1 ; Hofmann, S.^2 ; Oganessian, Y.T.^3

Department of Physics and Astronomy, Vanderbilt University, Nashville

TN

37235, United States^1

GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt

64291, Germany^2

Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna

141980, Russia^3

关键词: Macroscopic model;    Microscopic models;    Separation energy;    Shell correction;    Single-particle energy;    Spherical shape;    Spontaneous fission;    Super-heavy element;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/580/1/012019/pdf
DOI  :  10.1088/1742-6596/580/1/012019

来源: IOP

【 摘 要 】

The importance of shell closures and gaps in the single-particle energies for protons and neutrons on the stability of elements beyond Z 100 will be described. Following the development of microscopic models with shell corrections, microscopic-macroscopic models predicted large gaps in the single-particle energy levels for protons and neutrons at Z 102, 108 and N 152, 162 for the same deformed shapes. Shell gaps for spherical shapes for N 184 and Z 114, 120 or 126 were also predicted to form an "Island of Stability" with very long half lives for fission and alpha decay. Cold fusion reactions involving beams of Ca to Zn and targets of stable208Pb and209Bi were pioneered at GSI and used to synthesize new elements for Z 107 to 112 and in Japan a new isotope of 113. Hot fusion reactions between radioactive actinide targets and neutron-rich48Ca beams were pioneered in JINR leading to the synthesis of new elements with Z 113 to 118. Data on two neutron separation energies, spontaneous fission half lives and total half lives of super heavy elements showing the importance of reinforcement of the Z 102, N 152 and Z 108, N 162 single particle level gaps at the same deformation and Z 114-126, N 184 shell gaps in the synthesis of super heavy elements 107 to 118 are presented along with the latest results on their synthesis.