Chushnyakova M.V.,Omsk State Technical University |
Bhattacharya R.,University of Calcutta |
Gontchar I.I.,Omsk State Transport University
Physical Review C - Nuclear Physics | Year: 2014
Background: In our previous paper [Gontchar, Phys. Rev. C 89, 034601 (2014)PRVCAN0556-281310.1103/PhysRevC.89.034601] we have calculated the capture (fusion) excitation functions for several reactions with O16,Si28, and S32 nuclei as the projectiles and Zr92,Sm144, and Pb208 nuclei as the targets. These calculations were performed by using our fluctuation-dissipation trajectory model based on the double-folding approach with the density-dependent M3Y NN forces that include the finite range exchange part. For the nuclear matter density the Hartree-Fock approach with the SKP coefficient set that includes the tensor interaction was applied. It was found that for most of the reactions induced by O16 the calculated cross sections cannot be brought into agreement with the data. This suggested that the deviation in the calculated nuclear density for O16 from the experimental one was crucial. Method: The SKX parameter set is used to obtain the nuclear densities. Reactions with C12 and S36 as the projectiles and Pb204 as the target are included in the analysis in addition to those of the previous paper. Only data that correspond to the collision energy Ec.m.>1.1UB0 (UB0 is the s-wave fusion barrier height) are included in the analysis. The radial friction strength KR is used as the individual adjustable parameter for each reaction. Results: For all 13 reactions (91 points) it is possible to reach an agreement with the experimental fusion cross sections within 10%. Only at ten points does the deviation exceed 5%. The value of KR, which provides the best agreement with the data in general, decreases as the system gets heavier in accord with the previous paper [Gontchar, Phys. Rev. C 89, 034601 (2014)PRVCAN0556-281310.1103/PhysRevC.89.034601]. A universal analytical approximation for the dependence of KR upon the Coulomb barrier height is found. Conclusions: The developed model is able to reproduce the above-barrier portion of the fusion excitation function within 5% with a probability of 90%. Only one fitting parameter per excitation function KR is used. The model can be used to predict the results of relevant measurements. The universal analytical approximation of the KR dependence upon the Coulomb barrier height helps to find the starting value of KR for a more accurate description. © 2014 American Physical Society.
Chushnyakova M.V.,Omsk State Transport University |
Gontchar I.I.,Tomsk Polytechnic University
Pramana - Journal of Physics | Year: 2015
Evolution of the fusion cross-section in the 16O+16O reaction has been analysed. It is shown, both analytically and numerically, that in this excitation function some oscillations can be observed. These oscillations are related to the quantum character of the orbital angular momentum increase as well as to the distinct features of the 16O+16O reaction. In order to perform the numerical calculations, the fluctuation-dissipation model and the single barrier penetration model are used. It turns out that the experimental data available in the literature do not have any definite proof about the presence or absence of the oscillations. We stress, that the question still remains unanswered for more than three decades whereas during this time lapse the experimental errors for other reactions are reduced to 1-2%. © Indian Academy of Sciences.
Agency: Cordis | Branch: FP7 | Program: CSA-SA | Phase: SST-2007-6.0-01;SST-2007-6.0-02 | Award Amount: 506.34K | Year: 2008
Contributing to the European Research Area in surface transport to strengthen the competitiveness of the European surface transport sector. This will be achieved by using the excellent EURNEX competence to provide research excellence capabilities to European Small and Medium Size Enterprises (SMEs). Furthermore the cooperation with research excellencies from non EU countries will stimulate research that is of mutual interest and strengthen the European as well as non European research excellencies. EURNEX, the European Rail Research Network of Excellence, started on 01 January 2004 and has been granted for 4 years with 6 Mio within the 6th Framework Programme of EC. It involves 66 research institutes from 20 European countries and the associations of industry and operators UNIFE, UIC and UITP. More than 80 % of the members cover not only the rail research domain but surface transport. EURNEX supports the aims of the EC to see an interoperable and harmonised European rail system contributing to co-modality and a strong internationally competitive European railway industry by integrating the fragmented research, sharing knowledge and coordinating current research. The main benefits for the integration of non EU researchers in EURNEX are the scientific exchange on an international level, the training of junior scientists and researchers using the EURNEX assets, the identification of research areas that are of mutual interest, and the solving of problems in the international railway sector with European know how. The main benefits, that SMEs contributing as associated partners in EURNEX can gain, are an overview of the state of the art of the surface transport sector as a whole as well as specific topics, an insight in current research trends, an evaluation of their individual know how (respecting sensitive information), and an access to excellent research capabilities and test facilities.
Aktaev N.E.,Omsk State Transport University |
Gonchar I.I.,Omsk State Transport University
Bulletin of the Russian Academy of Sciences: Physics | Year: 2011
We present a detailed comparison of the analytical Kramers fission rate (KFR) and the dynamic quasi-stationary rate (QSFR) obtained by numerical simulation. It turns out that for the polynomial poten- tial, the KFR regularly exceeds the QSFR by more than 5%. We obtain KFR corrections that allow us to reduce this disparity to 1%. © 2011 Allerton Press, Inc.
Gontchar I.I.,Omsk State Transport University |
Chushnyakova M.V.,Omsk State Transport University
Computer Physics Communications | Year: 2013
We present a C-code designed to obtain the interaction potential between a spherical projectile nucleus and an axial-symmetrical deformed target nucleus and in particular to find the Coulomb barrier, by using the double folding model (DFM). The program calculates the nucleus-nucleus potential as a function of the distance between the centers of mass of colliding nuclei as well as of the angle between the axis of symmetry of the target nucleus and the beam direction. The most important output parameters are the Coulomb barrier energy and the radius. Since many researchers use a Woods-Saxon profile for the nuclear term of the potential we provide an option in our code for fitting the DFM potential by such a profile near the barrier. © 2012 Elsevier B.V. All rights reserved.