4,227 research outputs found
Superheavy element production, nucleus-nucleus potential and mu-catalysis
The semi-microscopic potential between heavy nuclei is evaluated for various
colliding ions in the approach of frozen densities in the framework of the
extended Thomas-Fermi approximation with hbar^2 correction terms in the kinetic
energy density functional. The proton and neutron densities of each nucleus are
obtained in the Hartree-Fock-BCS approximation with SkM* parameter set of the
Skyrme force. A simple expression for the nuclear interaction potential between
spherical nuclei is presented. It is shown that muon bound with light
projectile induces the superheavy elements production in nucleus-nucleus
collisions.Comment: 9 pages, 4 figures, RevTex, Tours 5 Symposium on Nuclear Physics,
Tours, August 200
Model for compound nucleus formation in various heavy-ion systems
The statistical model for the calculation of the compound nucleus formation
cross section and the probability of compound nucleus formation in heavy-ion
collisions is discussed in detail. The light, heavy, and super-heavy
nucleus-nucleus systems are considered in this model in the framework of one
approach. It is shown that the compound nucleus is formed in competition
between passing through the compound-nucleus formation barrier and the
quasi-elastic barrier. The compound-nucleus formation barrier is the barrier
separating the system of contacting incident nuclei and the spherical or
near-spherical ground state of the compound nucleus. The quasi-elastic barrier
is the barrier between the contacting and well-separated deformed ions. It is
shown that the compound nucleus formation cross-section is suppressed when the
quasi-elastic barrier is lower than the compound nucleus formation barrier. The
critical value of angular momentum, which limits the compound nucleus formation
cross-section values for light and medium ion-ion systems at over-barrier
collision energies, is discussed in the model. The suppression of the compound
nucleus formation cross-section even at small partial waves for very heavy
ion-ion systems is obtained in the model. The values of the capture and
compound nucleus formation cross-sections calculated for various light, heavy,
and super-heavy nucleus-nucleus systems as well as the probability of the
compound nucleus formation for super-heavy nuclei are well agreed with the
available experimental data.Comment: 17 pages, 6 figures, 2 table
Large-scale Ferrofluid Simulations on Graphics Processing Units
We present an approach to molecular-dynamics simulations of ferrofluids on
graphics processing units (GPUs). Our numerical scheme is based on a
GPU-oriented modification of the Barnes-Hut (BH) algorithm designed to increase
the parallelism of computations. For an ensemble consisting of one million of
ferromagnetic particles, the performance of the proposed algorithm on a Tesla
M2050 GPU demonstrated a computational-time speed-up of four order of magnitude
compared to the performance of the sequential All-Pairs (AP) algorithm on a
single-core CPU, and two order of magnitude compared to the performance of the
optimized AP algorithm on the GPU. The accuracy of the scheme is corroborated
by comparing the results of numerical simulations with theoretical predictions
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