Large Mass Transfer Reaction and Production of Neutron Rich Superheavy Nuclei

Key words: 
• large mass transfer reaction /
• superheavy nuclei /
• U+U reaction /
• heavy neutron-rich nuclei

Abstract: For elements with Z > 100 only neutron deficient isotopes have been synthesized so far. The “northeast area” of the nuclear map can be reached neither in fusion-fission reactions nor in fragmentation processes.The large mass transfer reactions in near barrier collisions of heavy (U-like) ions seem to be the only reaction mechanism allowing us to produce neutron rich heavy nuclei including those located at the superheavy(SH) island of stability and unexplored area of heavy neutron-rich nuclides. This study is extremely important for nuclear astrophysical investigations and, in particular, for the understanding of the r process. In this paper within the Improved Quantum Molecular Dynamics (ImQMD) model combining with the statistical-evaporation model, the large mass transfer reactions, like 238U+238U have been studied. The charge and mass distributions of transiently formed primary fragments are investigated within the ImQMD model and de-excitation processes of those primary fragments are described by the statistical decay model. The mass distribution of the final products in ²³⁸U+²³⁸U collisions is obtained and compared with the recent experimental data. Through compared the formation cross sections of transfermium element 106 by three reactions of ¹³⁶Xe+²⁴⁸Cm, ⁴⁸Ca+²⁴⁸Cm and ²³⁸U+²⁴⁸Cm, it is explored that the large mass transfer reactions, like U+U are very benefit for the production of SH nuclei.