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Dubovichenko S.B.,Institute of Space Technology | Dubovichenko S.B.,Institute of Nuclear Physics of Kazakhstan
Russian Physics Journal | Year: 2012

Possibility of description of experimental data on total cross sections of radiative n 2H capture is considered within the framework of the potential cluster models with forbidden states. It is demonstrated that the employed model can describe correctly the behavior of the experimental data at energies from 10 meV (10 -2 eV) to 15 MeV. © 2012 Springer Science+Business Media, Inc.


Dubovichenko S.B.,National Institute for Space Research | Dubovichenko S.B.,Institute of Nuclear Physics of Kazakhstan
Russian Physics Journal | Year: 2011

The experimental data on the astrophysical S-factor of the p2H radiative capture are well described for energies from 1 keV to 10 MeV using the potential cluster model and the Young schemes of orbital cluster state classification with allowance for the E1 and M1 transitions. © 2011 Springer Science+Business Media, Inc.


Dubovichenko S.B.,V G Fessenkov Astrophysical Institute Ncsrt Nsa Rk | Dzhazairov-Kakhramanov A.V.,Institute of Nuclear Physics of Kazakhstan
Annalen der Physik | Year: 2012

The possibility to construct intercluster interaction potentials in continuous and discrete spectra is shown in one-channel cluster model based on the classification of orbital states according to Young schemes. These potentials usually contain Pauli forbidden states, and correctly describe elastic scattering phase shifts taking into account resonance behavior and main characteristics of the bound states of nuclei in the considering cluster channel. The versions of intercluster interaction potentials describing the resonance nature of some phase shifts of the n7Li elastic scattering at low energies and the P2 ground state of 8Li in the n7Li cluster channel have been constructed for the demonstration of this approach. The possibility of describing the total cross sections of 7Li (n,γ)8Li within the energies from 5 meV (5·10-3 eV) to 1 MeV, including resonance at 0.25 MeV, has been demonstrated for the potentials obtained in the potential cluster model with forbidden states. The possibility to construct intercluster interaction potentials in continuous and discrete spectra is shown in one-channel cluster model based on the classification of orbital states according to Young schemes. These potentials usually contain Pauli forbidden states, and correctly describe elastic scattering phase shifts taking into account resonance behavior and main characteristic Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Dubovichenko S.B.,Vg Fessenkov Astrophysical Institute | Dubovichenko S.B.,Institute of Nuclear Physics of Kazakhstan
Physics of Atomic Nuclei | Year: 2012

A standard partial-wave analysis was performed on the basis of known measurements of differential cross sections for elastic p13C scattering at energies in the range 250-750 keV. This analysis revealed that, in the energy range being considered, it is sufficient to take into account the 3S1 wave alone. A potential for the triplet 3S1-wave state of the p13C system in the region of the JpT = 1-1 resonance at 0. 55 MeV was constructed on the basis of the phase shifts obtained from the aforementioned partial-wave analysis. © 2012 Pleiades Publishing, Ltd.


Dubovichenko S.B.,Vg Fessenkov Astrophysical Institute | Dubovichenko S.B.,Institute of Nuclear Physics of Kazakhstan
Physics of Atomic Nuclei | Year: 2012

The possibility of describing experimental data on the astrophysical S factor for radiative proton capture on a 13C nucleus at energies in the range 0.03-0.8 MeV is considered within the potential cluster model involving forbidden states. It is shown that the energy dependence of this astrophysical S factor can be reasonably explained on the basis of the E1 transition to the 3P1-wave bound state of the 14N nucleus in the p13C channel from the 3S1 wave of p13C scattering in the resonance energy region around 0.55 MeV in the laboratory frame. © 2012 Pleiades Publishing, Ltd.


Silachyov I.,Institute of Nuclear Physics of Kazakhstan
Journal of Radioanalytical and Nuclear Chemistry | Year: 2016

The application of instrumental neutron activation analysis for the determination of long-lived rare earth elements (REE) in rock samples is considered in this work. Two different methods are statistically compared: the well established external standard method carried out using standard reference materials, and the internal standard method (ISM), using Fe, determined through X-ray fluorescence analysis, as an element-comparator. The ISM proved to be the more precise method for a wide range of REE contents and can be recommended for routine practice. © 2016 Akadémiai Kiadó, Budapest, Hungary


Krassovitskiy P.M.,Institute of Nuclear Physics of Kazakhstan | Pen'kov F.M.,Institute of Nuclear Physics of Kazakhstan
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2014

Probabilities of resonant tunneling through a potential barrier are compared for a rigid molecule and an excited molecule. It is shown that the resonance spectrum is mainly governed by the transmission resonance spectrum of the rigid molecule. Analytical expressions for the probability for the tunneling of the rigid molecule through a barrier allow resonance-spectrum-averaged observables, including quantum diffusion, to be estimated. © 2014 IOP Publishing Ltd.


Yakushev E.,Institute of Nuclear Physics of Kazakhstan
Advances in Imaging and Electron Physics | Year: 2013

The central particle method significantly expands our capability to analyze the time-of-flight structure of electron and ion beams, particularly in situations when the classical conditions of paraxial approximation fall apart and the beams are non-stationary. A generalized mathematical framework is presented that allows the analysis of the focusing properties of electron particle beams in electron and ion mirrors, as well as in cathode lenses, including computations of coeffcients of spatial and time-of-flight aberrations. Conditions are defined under which ion mirrors with a non-stationary electrostatic field can be used to provide spatial focusing and time-of-flight energy focusing of ion packets in a time-of-flifht mass-spectrometer. New theoretical possibilities of utilization of electron mirrors as correctors of the main aberrations of electron lenses in electron microscopy are also discussed. © 2013 Elsevier Inc.


Dubovichenko S.B.,Fessenkov Astrophysical Institute | Dubovichenko S.B.,Institute of Nuclear Physics of Kazakhstan
Physics of Atomic Nuclei | Year: 2011

Within the potential cluster model where orbital states are classified according to Young diagrams and isospin, astrophysical S factors are considered for radiative proton capture by 3H and 7Li nuclei at energies of up to 1 and 10 keV, respectively. It is shown that the approach used, which takes into account only the E1 transition for the p3H capture process, makes it possible to describe well the most recent experimental data at c. m. energies in the range from 50 keV to 5MeV. In the case of proton capture by 7Li nuclei, an M1 processwas taken into account in addition to the E1 transition, and a general behavior and the magnitude of the experimental S factor could be correctly reproduced owing to this at astrophysical energies, including the region around the resonance at 0.441 MeV (in the laboratory frame). © 2011 Pleiades Publishing, Ltd.


Dubovichenko S.B.,Institute of Nuclear Physics of Kazakhstan
Physics of Particles and Nuclei | Year: 2013

Results obtained in the studies of radiative neutron capture on light nuclei at thermal and astrophysical energies are reviewed. The capture reactions in question are part of the primordial nucleosynthesis reaction chain underlying formation and development of the Universe. The reactions are treated within the potential cluster model with orbital states of clusters classified by Young diagrams. It is demonstrated that the intercluster potentials obtained from the phase shift analysis and description of the main characteristics of bound nuclear states in cluster channels can be used for the analysis of radiative capture characteristics. © 2013 Pleiades Publishing, Ltd.

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