Entrance Channel Dynamics of Hot and Cold Fusion Reactions Leading to Superheavy Elements

One of the most fascinating research areas involving low-energy nuclear reactions is the search for superheavy elements. Experimentally, two approaches have been used for the synthesis of these elements, one utilizing closed shell nuclei with lead-based targets (cold-fusion), the other utilizing deformed actinide targets with $^{48}$Ca projectiles (hot-fusion). In this talk we investigate the entrance channel dynamics for the reactions $\mathrm{^{70}Zn}+\mathrm{^{208}Pb}$ and $\mathrm{^{48}Ca}+\mathrm{^{238}U}$ using the fully microscopic time-dependent Hartree-Fock (TDHF) theory coupled with a density constraint~[1-3]. We calculate excitation energies and capture cross-sections relevant for the study of superheavy formations. We discuss the deformation dependence of the ion-ion potential for the $\mathrm{^{48}Ca}+\mathrm{^{238}U}$ system and perform an alignment angle averaging for the calculation of the capture cross-section. The results show that this approach can generate results in good agreement with experiment and other theories.\\[4pt] [1] Umar, Oberacker, PRC 74, 061601(R) (2006).\\[0pt] [2] Umar, Oberacker, EPJA 39, 243 (2009).\\[0pt] [3] Umar, Maruhn, Itagaki, and Oberacker, PRL 104, 212503.