V. E. Oberacker

Potential pockets in the238U+238U system and their possible consequences

Within the double-folding model the separation, shape, and orientation dependence of the interaction potential is studied for two heavy ions. An effective nucleon-nucleon interaction (M3Y) derived fromG-matrix elements and based upon the Reid soft-core potential is used. Deformed Fermi-type matter densities with static quadrupole and hexadecapole deformations were utilized. The model is applied to the238U+238U system and shows dramatic dependence on the deformations and orientations.

Heavy-ion interaction potential deduced from density-constrained time-dependent Hartree-Fock calculation

We present a new method for calculating the heavy-ion interaction potential from a density-constrained time-dependent Hartree-Fock calculation.

Three-dimensional unrestricted time-dependent Hartree-Fock fusion calculations using the full Skyrme interaction

We present a study of fusion cross sections using a new generation Time-Dependent Hartree-Fock (TDHF) code which contains no approximations regarding collision geometry and uses the full Skyrme interaction, including all of the time-odd terms. In addition, the code uses the Basis-Spline collocation method for improved numerical accuracy. A comparative study of fusion cross sections for

Axially symmetric Hartree-Fock-Bogoliubov Calculations for Nuclei Near the Drip-Lines

^{16}O + ^{16,28}O

Energy dependence of potential barriers and its effect on fusion cross sections

is made with the older TDHF results and experiments. We present results using the modern Skyrme forces and discuss the influence of the new terms present in the interaction.

Entrance channel dynamics of hot and cold fusion reactions leading to superheavy elements

Department of Physics and Astronomy,Vanderbilt University, Nashville, TN 37235, USA(Dated: June 25, 2011)Nuclei far from stability are studied by solving the Hartree-Fock-Bogoliubov (HFB) equations,which describe the self-consistent mean field theory with pairing interaction. Calculations for even-even nuclei are carried out on a two-dimensional axially symmetric lattice, in coordinate space. Thequasiparticle continuum wavefunctions are considered for energies up to 60 MeV. Nuclei near thedrip lines have a strong coupling between weakly bound states and the particle continuum. Thismethod gives a proper description of the ground state properties of such nuclei. High accuracy isachieved by representing the operators and wavefunctions using the technique of basis-splines. Thedetailed representation of the HFB equations in cylindrical coordinates is discussed. Calculationsof observables for nuclei near the neutron drip line are presented to demonstrate the reliability ofthe method.

Dissipative dynamics in quasifission

Background: Couplings between relative motion and internal structures are known to affect fusion barriers by dynamically modifying the densities of the colliding nuclei. The effect is expected to be stronger at energies near the barrier top, where changes in density have longer time to develop than at higher energies. This gives rise to an energy dependence of the barriers as predicted by modern time-dependent Hartree-Fock (TDHF) calculations [K. Washiyama and D. Lacroix, Phys. Rev. C 78, 024610 (2008)]. Quantitatively, modern TDHF calculations are able to predict realistic fusion thresholds. However, the evolution of the potential barrier with bombarding energy remains to be confronted with the experimental data.

Time-dependent response calculations of nuclear resonances

We investigate the entrance channel dynamics for the reactions {sup 70}Zn+{sup 208}Pb and {sup 48}Ca+{sup 238}U by using the fully microscopic time-dependent Hartree-Fock theory coupled with a density constraint. 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 {sup 48}Ca+{sup 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 experiments and other theories.

Coordinate space Hartree-Fock-Bogoliubov calculations for the zirconium isotope chain up to the two-neutron drip line

Quasifission is the primary reaction mechanism that prevents the formation of superheavy elements in heavy-ion fusion experiments. Employing the time-dependent density functional theory approach, we study quasifission in the systems

Microscopic study of Ca + Ca fusion

^{40,48}\mathrm{Ca}+^{238}\mathrm{U}