Dynamics of the synthesis of superheavy elements

Present status of the study of superheavy elements is reviewed. The dynamical process of synthesizing superheavy elements is studied on the basis of the fluctuation-dissipation dynamics. The whole process is divided into three stages, i.e., the approaching stage, the formation stage, and the surviving stage. For the study of the formation stage, a three-dimensional Langevin equation is used after the contact of two nuclei to calculate the competition between the complete fusion and the quasi-fission. For the description of the surviving stage, a statistical model is used to estimate the competition between the fission and the evaporation process. In this stage, it is very important to include the temperature-dependent shell correction to the fission barrier and the collective enhancement of the level density. From the study of the isotope dependence of the production cross section, the survival probability is found to be very sensitive to the separation energy of neutron. The results show the importance of the use of neutron-rich beams and targets.