87 research outputs found
Microscopic study of CaCa fusion
We investigate the fusion barriers for reactions involving Ca isotopes
, , and
using the microscopic time-dependent
Hartree-Fock theory coupled with a density constraint. In this formalism the
fusion barriers are directly obtained from TDHF dynamics. We also study the
excitation of the pre-equilibrium GDR for the
system and the associated -ray
emission spectrum. Fusion cross-sections are calculated using the incoming-wave
boundary condition approach. We examine the dependence of fusion barriers on
collision energy as well as on the different parametrizations of the Skyrme
interaction.Comment: 11 pages, 13 figure
Heavy-ion interaction potential deduced from density-constrained TDHF calculation
We present a new method for calculating the heavy-ion interaction potential
from a density-constrained time-dependent Hartree-Fock calculation.Comment: 4 pages, 3 figure
Microscopic Description of Nuclear Fission Dynamics
We discuss possible avenues to study fission dynamics starting from a
time-dependent mean-field approach. Previous attempts to study fission dynamics
using the time-dependent Hartree-Fock (TDHF) theory are analyzed. We argue that
different initial conditions may be needed to describe fission dynamics
depending on the specifics of the fission phenomenon and propose various
approaches towards this goal. In particular, we provide preliminary
calculations for studying fission following a heavy-ion reaction using TDHF
with a density contraint. Regarding prompt muon-induced fission, we also
suggest a new approach for combining the time-evolution of the muonic wave
function with a microscopic treatment of fission dynamics via TDHF
Microscopic Calculation of Fusion: Light to Heavy Systems
The density-constrained time-dependent Hartree-Fock (DC-TDHF) theory is a
fully microscopic approach for calculating heavy-ion interaction potentials and
fusion cross sections below and above the fusion barrier. We discuss recent
applications of DC-TDHF method to fusion of light and heavy neutron-rich
systems.Comment: 8 pages, 8 figure
Fusion using time-dependent density-constrained DFT
We present results for calculating fusion cross-sections using a new
microscopic 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
constraint on the density for DFT calculations.Comment: 4 Pages, 6 Figures Proceedings of INPC 2013, to be published in EPJ
Web of Conference
Microscopic DC-TDHF study of heavy-ion potentials and fusion cross sections
We study heavy-ion fusion reactions at energies near the Coulomb barrier, in
particular with neutron-rich radioactive ion beams. Dynamic microscopic
calculations are carried out on a three-dimensional lattice using the
Density-Constrained Time-Dependent Hartree-Fock (DC-TDHF) method. New results
are presented for the Sn+Ca system which are compared to
Sn+Ca studied earlier. Our theoretical fusion cross-sections
agree surprisingly well with recent data measured at HRIBF. We also study the
near- and sub-barrier fusion of O on C which is important to
determine the composition and heating of the crust of accreting neutron stars.Comment: Talk given by . Volker E. Oberacker at the 11th International
Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA,
May 27-June 1, 2012. To appear in the NN2012 Proceedings in Journal of
Physics: Conference Series (JPCS
Microscopic sub-barrier fusion calculations for the neutron star crust
Fusion of very neutron rich nuclei may be important to determine the
composition and heating of the crust of accreting neutron stars. Fusion cross
sections are calculated using time-dependent Hartree-Fock theory coupled with
density-constrained Hartree-Fock calculations to deduce an effective potential.
Systems studied include 16O+16O, 16O+24O, 24O+24O, 12C+16O, and 12C+24O. We
find remarkable agreement with experimental cross sections for the fusion of
stable nuclei. Our simulations use the SLy4 Skyrme force that has been
previously fit to the properties of stable nuclei, and no parameters have been
fit to fusion data. We compare our results to the simple S\~{a}o Paulo static
barrier penetration model. For the asymmetric systems 12C+24O or 16O+24O we
predict an order of magnitude larger cross section than those predicted by the
S\~{a}o Paulo model. This is likely due to the transfer of neutrons from the
very neutron rich nucleus to the stable nucleus and dynamical rearrangements of
the nuclear densities during the collision process. These effects are not
included in potential models. This enhancement of fusion cross sections, for
very neutron rich nuclei, can be tested in the laboratory with radioactive
beams.Comment: 9 pages, 11 figures, corrected small errors in Figs 10, 11, Phys.
Rev. C in pres
3-D unrestricted TDHF 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 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.Comment: 7 pages, 10 figure
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