Nucleon Transfer Reactions in Very Heavy Ion Systems

Abstract

Nucleon transfer reactions in the $^{238}$U + $^{238}$U system were studied at the energies $E_\mathrm{eff}= 6.3$ MeV/u, $E_\mathrm{eff} = 6.9$ MeV/u, and $E_\mathrm{eff} = 8.0$ MeV/u, respectively. Production of above-target nuclides point to formation of transfer products with excitation energies between 30 and 40 MeV and angular momenta of about 18 $\hbar$, independent of bombarding energy. Predictions of heavy element production rates up to lawrencium ($Z=103$) in the system $^{238}$U + $^{248}$Cm showed that yields drop sharply with increasing number of transferred protons leaving little perspective for possible future production of new neutron-rich isotopes in this reaction. However, a recent theoretical prediction claimed much higher cross sections for elements lawrencium ($Z=103$) and higher due to assumed increased longer sticking times of the dinuclear system.