58 research outputs found
Friction Coefficient for Deep-Inelastic Heavy-Ion Collisions
Based on the microscopic model, the friction coefficient for the relative
motion of nuclei in deep-inelastic heavy-ion collisions is calculated. The
radial dependence of the friction coefficient is studied and the results are
compared with those found by other methods. Based on this result, it was
demonstrated that the kinetic energy dissipation in deep-inelastic heavy-ion
collisions is a gradual process which takes up a significant part of a reaction
time. An advantage of the suggested method is that it allows one to consider
the relative motion of nuclei and the intrinsic motion self-consistently.Comment: 15 pages, RevTex, 7 Postscript figures, submitted to Phys. Rev.
On stability of the neutron rich Oxygen isotopes
Stability with respect to neutron emission is studied for highly
neutron-excessive Oxygen isotopes in the framework of Hartree-Fock-Bogoliubov
approach with Skyrme forces Sly4 and Ska. Our calculations show increase of
stability around 40O.Comment: 5 pages, 3 figure
Mechanism of Lattice-Distortion-Induced Electric-Polarization Flop in the Multiferroic Perovskite Manganites
Magnetoelectric phase diagrams of the perovskite manganites, Eu1-xYxMnO3 and
Gd1-xTbxMnO3, are theoretically studied. We first construct a microscopic
model, and then analyze the model using the Monte-Carlo method. We reproduce
the diagrams, which contain two different multiferroic states, i.e., the
ab-plane spin cycloid with electric polarization P//a and the bc-plane spin
cycloid with P//c. We reveal that their competition originates from a conflict
between the single-ion anisotropy and the Dzyaloshinsky-Moriya interaction,
which is controlled by the second-neighbor spin exchanges enhanced by the
GdFeO3-type distortion. This leads to a P flop from a to c with increasing x in
agreement with the experiments.Comment: 5 pages, 5 figures. Recalculated results after correcting errors in
the assignment of DM vectors. The conclusion is not affecte
Nuclear Fission: : A Review of Experimental Advances and Phenomenology
In the last two decades, through technological, experimental and theoretical advances, the situation in experimental fission studies has changed dramatically. With the use of advanced production and detection techniques both much more detailed and precise information can now be obtained for the traditional regions of fission research and, crucially, new regions of nuclei have become routinely accessible for fission studies. This work first of all reviews the recent developments in experimental fission techniques, in particular the resurgence of transfer-induced fission reactions with light and heavy ions, the emerging use of inverse-kinematic approaches, both at Coulomb and relativistic energies, and of fission studies with radioactive beams. The emphasis on the fission-fragment mass and charge distributions will be made in this work, though some of the other fission observables, such as prompt neutron and γ-ray emission will also be reviewed. A particular attention will be given to the low-energy fission in the so far scarcely explored nuclei in the very neutron-deficient lead region. They recently became the focus for several complementary experimental studies, such as β-delayed fission with radioactive beams at ISOLDE(CERN), Coulex-induced fission of relativistic secondary beams at FRS(GSI), and several prompt fusion-fission studies. The synergy of these approaches allows a unique insight in the new region of asymmetric fission around <sup>180</sup>Hg, recently discovered at ISOLDE. Recent extensive theoretical efforts in this region will also be outlined. The unprecedented high-quality data for fission fragments, completely identified in <i>Z</i> and <i>A</i>, by means of reactions in inverse kinematics at FRS(GSI) and VAMOS(GANIL) will be also reviewed. These experiments explored an extended range of mercury-to-californium elements, spanning from the neutron-deficient to neutron-rich nuclides, and covering both asymmetric, symmetric and transitional fission regions. Some aspects of heavy-ion induced fusion-fission and quasifission reactions will be also discussed, which reveal their dynamical features, such as the fission time scale. The crucial role of the multi-chance fission, probed by means of multinucleon-transfer induced fission reactions, will be highlighted. The review will conclude with the discussion of the new experimental fission facilities which are presently being brought into operation, along with promising 'next-generation' fission approaches, which might become available within the next decade
DFMSPH19: A C-code for the double folding interaction potential of two spherical nuclei
This is a new version of the DFMSPH (DFMSPH14) code published earlier. The new version is designed to obtain the nucleus–nucleus potential between two spherical nuclei by using the double folding model (DFM). In particular, the code enables to find the Coulomb barrier. Using the new version one can employ two types of the nucleon–nucleon interaction: the M3Y and Migdal interactions. The main functionalities of the original code (the nucleus–nucleus potential as a function of the distance between the centers of mass of colliding nuclei and the Coulomb barrier characteristics) have been extended: in the new version the curvature and skewness of the barrier (in addition to its height and radius) are evaluated
DFMSPH22: A C-code for the double folding interaction potential of two spherical nuclei
This is a new version of the DFMSPH (DFMSPH14, DFMSPH19) code published earlier. The new version is designed to obtain the nucleus–nucleus potential between two spherical nuclei using the double folding model (DFM). In particular, the code enables one to find the Coulomb barrier. Using the new version, one can employ three types of effective nucleon–nucleon interaction: the M3Y, Migdal, and relativistic mean-field interactions. The main functionalities of the original code (the nucleus–nucleus potential as a function of the distance between the centers of mass of colliding nuclei and the characteristics of the Coulomb barrier) are retained. The new version enables using proton or neutron as the projectile particle for all nucleon–nucleon interactions but the Migdal one
Damping coefficient of the fission mode analysis of experimental data with a combination of a dynamical and statistical model
Combining a dynamical and statistical approach to the competition between fission and particle emission
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