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

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