Fusion using time-dependent density-constrained DFT
We present results for calculating fusion cross-sections using a new micro- scopic approach based on a time-dependent density-constrained DFT calculations. The theory is implemented by using densities and other information obtained from TDDFT time-evolution of the nuclear system as a constraint on the density for DFT calculations. The investigation of internuclear potentials for heavy-ion collisions is of fundamental importance for the study of fusion reactions as well as for the formation of superheavy elements and nuclei far from stability. Recently, we have developed a new method to extract ion-ion interaction potentials directly from the time-dependent Hartree-Fock (TDHF) time-evolution of the nuclear system (1). In the density-constrained TDHF (DC-TDHF) approach the TDHF time-evolution takes place with no restrictions. At certain times during the evolution the instantaneous density is used to perform a static Hartree-Fock minimization while holding the neutron and proton densities constrained to be the corresponding instantaneous TDHF densities. In essence, this provides us with the TDHF dynamical path in relation to the multi-dimensional static energy surface of the combined nuclear system. In this approach there is no need to introduce constraining operators which assume that the collective motion is confined to the constrained phase space. In short, we have a self-organizing system which selects its evolutionary path by itself following the microscopic dynamics. Some of the e ects naturally included in the DC-TDHF calculations are: neck formation, mass exchange, internal excitations, deformation e ects to all order, as well as the e ect of nuclear alignment for deformed systems. The DC-TDHF theory provides a comprehensive approach to calculating fusion barriers in the mean-field limit. The fusion cross-sections are subsequently calculated by integrating the Schrodinger equation using the incoming-wave boundary condition method (IWBC) as outlined in Ref. (2). The theory has been applied to calculate fusion cross-sections for a large number of systems (2-8). In this contribution we will outline the DC-TDHF method and give new examples of its application to the calculation of fusion cross-sections for several systems.