Production of neutron-rich transcalifornium nuclei in 238U-induced transfer reactions

In order to produce more unknown neutron-rich transcalifornium nuclei, the collisions of U-238 with the targets Cm-248, Cf-249, and Cm-250 are investigated within the framework of the dinuclear system model. The production cross sections of unknown neutron-rich nuclei with Z = 99-104 in these reactions are predicted. The influences of N/Z ratios and charge numbers of the targets on the production cross sections are studied. It is found that high N/Z ratios of Cm-248 and Cm-250 targets enhance the production cross sections of neutron-rich transcalifornium nuclei. However, due to high charge number of the target Cf-249 the predicted production cross sections of unknown neutron-rich nuclei with Z = 104 in the reaction U-238+ Cf-249 are higher than those in U-238+ Cm-248. We also have studied the entrance angular momentum effects on production probabilities of transfer products in the reaction U-238+ Cm-248. It is found that the formation probabilities of the final neutron-rich products increase first and then decrease with the increasing J.