THE CALCULATION OF ⁹Be(d,n)¹⁰B NEUTRON SOURCE CHARACTERISTICS AT E_d < 2,5 МEV

V.A. Tsymbal, N.D.Masalitin, S.A. Pismenetskiy, V.G. Rudychev, Y.V. Rudychev, A.F.Stoyanov

Full Text :   (402 kB, Rus.) 

Abstract
There are summarized some relevant nuclear data and weighted means have been obtained for the cross-section of the ⁹Be(d,n)¹⁰B reaction at (0.5-3)MeV. With some model bringing in the expressions have been obtained for the neutron spectra from the thick target up to 2.5MeV deuteron energy. The dependence is calculated of the total reaction yield, which is similar to known earlier, but decreases the expected value of yield to (7..11) times in the energy region Е_d =1.5-2 MeV. These spectra and angular distributions of outgoing neutrons so as a total reaction yield can be used to design the compact neutron irradiator, in particular, for producing of short-live radioactive nuclides for therapy directly near the places of their application.

KEY WORDS: Neutron, deuteron, beryllium, neutron generator, neutron spectra.

ON THE THEORY OF A NON-LINEAR NEUTRAL SCALAR FIELD WITH SPONTANEOUSLY BROKEN SYMMETRY

Yu.M. Poluektov

Full Text :   (510 kB, Rus.) 

Abstract
An approach to quantization of the non-linear model for the real scalar field with spontaneously broken symmetry and construction of perturbation theory is suggested. The method is based on approximation of the model Hamiltonian by a self-consistent field Hamiltonian in which vacuum fluctuations are taken into account in construction of the one-particle states. The solutions of the self-consistent equations determine possible states which also include the state with the broken symmetry. The mass of the particles is determined by parameters of the Lagrangian and vacuum fluctuations. The density of the vacuum energy in these states is calculated. It is shown that the concept of Bogolubov's quasi-average can naturally be applied in definition of exact Green functions in the states with broken symmetries. Equations for the exact one- and two-point Green functions are obtained.

KEY WORDS: scalar field, broken symmetry, self-consistent field, perturbation theory, quasi-average

THE INVESTIGATION OF INTERACTION OF SUPERCONDUCTING OBJECTS WITH LOW MAGNETIC FIELDS

V.G. Kirichenko, V.I. Tkachenko, T.A. Kovalenko, P.L. Rudenko, M.S. Vasylenko

Full Text :   (650 kB, Rus.) 

Abstract
The paper is devoted to investigation of high-temperature superconductors (HTSC) and the superconducting casings interaction with low magnetic fields including those of nature origin. We investigate the interaction of superconducting objects of small average density until 3×10^-4 g/cm³ which was ideal diamagnetic. The results of investigations of HTSC interactions with low magnetic fields were included the experimental data in 3D-diagrams in F- P/V - H coordinates, which described the spreading regions of effective interaction observation in the direction of reduction of magnetic fields intensity.

KEY WORDS: high-temperature superconductors, Meissner effect, interaction, low magnetic fields, 3D-diagrams

ON THE RELATIVE ROLE OF THE PHONON SPECTRUM AND THE COLLISIONAL RELAXATION IN PROCESSES OF GENERATION AND SCATTERING

O.V. Kuklina, V.M. Kuklin

Full Text :   (313 kB, Rus.) 

Abstract
It is shown that the relaxation processes and processes with phonons participation are able to influence on the efficiency of HF generation and scattering in multilevel systems. In three- level system, where operating level inversion formed by large phonon intensity, the efficiency excitation of HF oscillation and photon spectrum are inversely proportional dissipation or energy emission outside. The low-energy scattering simultaneously up (anti-Stokes satellite) and down (Stokes satellite) with phonon excitation in transparent media is determined by spontaneous radiation effect. In cases of emission and absorption of high-energy quantum by nucleus when the kinetic energy recoil exceeds the value of potential barrier, which is holding the atom in lattice, the absorption and emission lines are separated as large as redoubled energy of recoil. If afterwards emission and absorption of high-energy quantum by nucleus, atom localization don't change, the motion of atom turn into oscillatory one. The quantum energy of such oscillator is equal an energy of recoil. Emission of such oscillator with excited nucleus is line spectrum of HF oscillation. The probability of radiation of spectral line with nuclear transition energy considerably exceed radiation probability of another lines. The intensity of radiation is found on conditions that the quantum with the same energy is absorbed also efficiently.

KEY WORDS: induced and spontaneous radiation, relaxation process, generation, scattering, phonons.

ANALYZING POWER OF THE HIGH ENERGY PHOTON POLARIMETERS BASED ON PROCESSES PAIR AND TRIPLET PHOTOPRODUCTION

D.D. Burdeinyi, V.B. Ganenko, Yu.P. Peresunko, I.M. Shapoval, G.A. Vashchenko

Full Text :   (1195 kB, Rus.) 

Abstract
In the work it is considered influence of experimental factors on analyzing power processes of e⁺e^—-pairs photoproduction in the field of nuclei and atomic electrons (triplet photoproduction), which can be used for measurement the linearly polarizations of photon beams in the energy range 30-3000 МeV. Modeling has shown that analyzing power of both processes does not practically depend on initial photon energy in the interval under study and can reach Λ~0.11 when there is no applied any selection of the events. The analyzing power of the processes can be increased up to Λ~0.2 at the e⁺e^—-pairs selection with close energies of electron and positron, or in the case of triplet photoproduction, if the recoil electron selection near the border of kinematically permitted region is used.

KEY WORDS: analyzing power, photon polarimeter, linear polarization, photoproduction e⁺e^—-pair, triplet photoproduction, recoil electrons, δ-electrons, symmetric pairs.

CONSTRUCTION MATERIALS FOR THE ELEMENTS OF EQUIPMENT OF NUCLEAR-POWER PLANTS

М. М. Pylypenko

Full Text :   (646 kB, Rus.) 

Abstract
The results of investigations of production of construction materials for the elements of equipment of nuclear-power plants are described. It was demonstrated that development of nuclear power engineering largely relies on developments of new perspective construction materials for new generation reactors and improvement of materials of the exploited nuclear-power plants. Results of researches of chemical composition, structure, and mechanical properties of Zr1Nb alloy ingots produced by double vacuum-arc melting (VAM) method are presented. Experimental-industrial batch of trex-pipes and pipes for fuel assemblies for VVER-type reactors was produced from ingots of Zr1Nb VAM-alloy. Data about the level of purity of metals of got different physical methods are resulted, on the basis of the conducted developments and realization of high-performance methods of refining. Using of high-pure metals as initial components of the construction materials of nuclear-power plants largely determines further development of nuclear energy: high-purity zirconium alloys and hafnium are needed for the improvement of the fuel assemblies and reactor control and safety system of operating nuclear-power plants; new high temperature, corrosion- and radiation-proof construction materials - basis of elements of constructions of new generation reactors, providing its high operating properties.

KEY WORDS: construction materials, zirconium alloy, hafnium, high-pure metals, alloys.

NUMERICAL STUDY OF FIRST ORBIT LOSSES OF TRAPPED PARTICLES IN TOKAMAKS

N.A. Azarenkov, Zh.S. Kononenko

Full Text :   (1130 kB, Rus.) 

Abstract
The analytical model of the 2D tokamak magnetic field for the test particle simulations is proposed. It is shown how to vary the model parameters to obtain the plasma shape with the different ellipticity and triangularity. The problems of the particle direct losses in tokamak are discussed. The loss cones of the particles are calculated for the different initial radial locations. The minimum trapped particle energy required to escape from the plasma due to the first orbit losses is found numerically for the different ion species.

KEY WORDS: rotational transform, Poincare plot, trapped and passing particles, direct losses, loss cone.

SOUND MODES IN ISOTROPIC MAGNETIC HYDRODYNAMICS

A.A. Stupka

Full Text :   (142 kB, Rus.) 

Abstract
Hydrodynamics of plasma in а magnetic field that has in equilibrium first moment of magnetic induction equal to the zero and second moment different from a zero is considered. Equations of ideal magnetic hydrodynamics in such field for adiabatic process are received. It is shown that a new variable - second moment of magnetic induction is included in the Euler equation, for which time equation is received on the basis of Maxwell equalizations in the hydromagnetic approach. One-dimension plane waves in this system are studied. The values of phase velocities of two transversal and one longitudinal sound waves are received.

KEY WORDS: isotropic magnetic hydrodynamics, second moment of the magnetic induction, one-dimension plane waves, sound modes, transversal sound velocity.

THE COMPUTER PROCESSING OF THE PLASMA ULTRAVIOLET SOURCE CHARACTERISTICS OF THE MEASUREMENTS RESULTS

A.V. Pochynok, V.T. Lazurik, A.F. Tseluyko, E.V. Borgun

Full Text :   (245 kB, Rus.) 

Abstract
The technique of the analysis of the primary scientific data to the results of measurements of plasma ultraviolet sources characteristics is applied to reveal the latent physical laws. The set of information parameters for empirical dependences obtained in the process of measurements is determined. Calculation of values of information parameters is carried out using the software "PSData2". Results of the carried out correlation analysis of the information parameters of the empirical dependences obtained in the experimental of investigation of high-current plasma diode radiation characteristics are presented. Physical laws observable in a series of experiments are revealed that to show a correctness of used numerical methods of the results measurement processing realized in the software "PSData2".

KEY WORDS: plasma discharge, ultraviolet source, results measurement processing, empirical dependences, software.

SIMULATION OF VENTILATED CONTAINER OF STORAGE BY LINAC BREMSSTRAHLUNG

A.V. Lisitsky, S.A. Pismenesky, V.G. Rudychev

Full Text :   (264 kB, Rus.) 

Abstract
Methods of calculation of tungsten and iron e-γ-converter optimal characteristics are considered. These converters have been recommended to use for simulation γ-radiation near storage container of by means of linac bremsstrahlung. Right reconstruction of the irradiation is important problem. The problem solution will give a possibility to study of the irradiation influence to equipment and personnel of nuclear waste dry storage. Carried out calculations was based on the container radiation field characteristics. Simulation of the fields is necessary for testing shields, detectors and for other problems of the storage using. For simulation of radiation transport processes in matter PENELOPE program was used.

KEY WORDS: simulation, γ-radiation, converter, bremsstrahlung, linac, PENELOPE

GENERALIZATION OF THE KOLMOGOROV-JOHNSON-MEHL-AVRAMI THEORY TO THE CASE OF GROWTH LAW OF DIFFUSIONAL TYPE

N.V. Alekseechkin

Full Text :   (365 kB, Rus.) 

Abstract
The problem of calculating volume fraction of a phase with growth law of diffusional type is solved. Consideration is carried out in the framework of the Johnson-Mehl-Avrami approach which uses the concept of fictitious nuclei (phantoms). With the use of probabilistic reasoning, the application of fictitious mechanism of nucleation and growth is grounded and the works excluding phantoms are critically analyzed. The volume fraction of a phase with diffusion-controlled growth law is evaluated numerically. It is shown that effect of phantoms in this case is negligible.

KEY WORDS: phase, volume fraction, growth law, Kolmogorov-Johnson-Mehl-Avrami theory, phantom

ELEMENTAL AND PHASE COMPOSITION OF TITANIUM ALLOYS VT-22 IMPLANTED BY IONS W+ AND MO+

А.D. Pogrebnjak, V.M. Beresnev, S.N. Bratushka, L.V. Malikov

Full Text :   (475 kB, Rus.) 

Abstract
With the help of methods of back-scattering (RBS) of helium ions and protons, scanning electron microscopy (SEM) with a microanalysis EDS, WDS, X-ray phase analysis (XRD) in geometry of sliding beam (0.5°), Möossbauer spectroscopy (MS), nanoindentation were investigated samples of titanium alloys VT-22. The increase of hardness almost in 2 times, decreasing of wearing and increase of fatigue resistance is revealed due to formation of fine-dyspersated (nanodimension) intermetallide phases.

KEY WORDS: double implantion, nanohardness, types of distributing of elements, phase composition.

APPLICATION OF X-RAY PATTERN OF DIFDACTION ON DISLOCATION IN ANALYSIS OF STRAINS IN POLYCRYSTALLINE MATERIALS

D.G. Malykhin, V.V. Kornyeyeva

Full Text :   (290 kB, Rus.) 

Abstract
A brief analysis of problems of X-ray studies of microstructure characteristics, in particular microscopic strains of polycrystalline materials is carried out. A place in this area of X-ray investigations of developing dislocation conception of abnormal strains distribution is defined. A conformity of the dislocation pattern of diffraction on strains with the formalism of Voigt function techniques namely with using of Cauchy function is found. The physical sense of Cauchy function describing of strains distributions is explaining. Taking in account of arbitrary orientations of Burgers vectors of edge dislocations is made. The formula of dislocation density determination is corrected with taking into account of Burgers vectors disorientations.

KEY WORDS: X-ray analysis, diffraction, strains, dislocations, pattern, calculation, approximation, Voigt function, Cauchy function, anisotropy

STRUCTURE AND MAGNETIC PROPERTIES OF GAMMA ACTIVATED NANOPARTICLES OF MAGNETITE

N.P. Dikiy, E.P. Medvedeva, I.D. Fedorets, N.P. Khlapova, N.S. Lutsay

Full Text :   (265 kB, Rus.) 

Abstract
Activation of nanoparticles of magnetite is carried out by slowing-down γ - radiation on high-current electronic accelerator in NSC KIPT at energy of electrons 22 MeV and a current 500 μА. The comparative analysis of component-phase structure and state of crystal structure of activated and initial nanomagnetite was carried out by X-ray diffractometry and IR - spectroscopy methods. The magnetic properties of samples were investigated by magnetometric method. Radiative transformations have been analysed and it was shown that there were no essential changes in structure and properties of nanomagnetite. Activated nanoparticles of magnetite keep monophase state and crystallinity of initial state and have high level of saturation magnetization (M_s ~ 74 А×m²/kg), so they predetermine possibility of their usage as a magnetically operated radiopharmpreparation.

KEY WORDS: nanomagnetite, electron accelerator, gamma-activation, X-ray diffractometry, IR- spectroscopy, magnetometry, radiopharmpreparation

THE FEATURES OF FORMATION AND SIMULATION OF GRAPHITE MONOATOMIC LAYERS

V.G. Kirichenko, E.S. Melnikova

Full Text :   (1910 kB, Rus.) 

Abstract
The results of experimental investigation of simulation of graphite's monatomic layer formation process by data of scanning tunneling microscopy are presented. The periodic modulation of monatomic layer electron density on modeling cells is founded. Distribution to electronic density on both sides monatomic layer differs and correlates with smaller importance of the parameter hexagonal lattices. The observed differences on direction and scaling monatomic layer on atomic clean surface of the graphite are necessary to take into account at analysis of the processes of the graphane's and graphane's formation and receptions.

KEY WORDS: graphite, surface, graphene, structures, monatomic layer, modulation.

LOW PRESSURE GAS BREAKDOWN IN COMBINED ELECTRIC FIELDS

N.D. Kharchenko, V.A. Lisovskiy

Full Text :   (776 kB, Rus.) 

Abstract
In this work by analogy to the three modes of the combined (RF+DC) discharges existence, we distinguish the ignition of the combined discharges also in three modes: 1) RF breakdown perturbed by the DC electric field, 2) breakdown in the combined field, 3) DC breakdown perturbed by the RF electric field. It is shown that application of the DC voltage combined with the RF first increases the RF breakdown voltage compared to the breakdown voltage of self-sustained RF discharge. However at sufficiently high DC voltages the DC field starts to contribute to the ionization of gas molecules, RF breakdown voltage goes down with the increasing of the DC voltage applied to the combined discharge and equals to zero, when the self- sustained DC discharge ignites. The DC breakdown curve, influenced by the RF voltages higher than the minimum RF breakdown voltage Urf.min, consists of two parts.

KEY WORDS: combined discharge, RF capacitively coupled discharge, DC discharge, gas breakdown, low pressure discharge, nitrogen, argon.

EFFECT OF HIGH PRESSURE ON TEMPERATURE DEPENDENCE OF THE PSEUDOGAP IN SLIGHTLY OXYGEN DOPED YBa₂Cu₃O_7-δ   SINGLE CRYSTALS

A.A. Zavgorodniy, R.V. Vovk, M.A. Obolenskii, A.V. Samoylov

Full Text :   (300 kB, Rus.) 

Abstract
In present work the effect of high pressure on conductivity in the base plane of oxygen deficient YBa₂Cu₃O_7-δ single crystals was investigated. The excess conductivity Δσ(Т) for the YBa₂Cu₃O_7-δ single crystals shows exponential dependence in the wide temperature range Tf<Т<T*. In addition ratio Δσ~(1-Т/Т*)exp(Δ*ab/T) can be interpreted in the mean field theory, where Т* represents as mean field temperature of superconducting transition and temperature dependence of the pseudogap can be described satisfastionaraly in term of crossover BSC-BEK theory. The increase of the enclosed pressure brings narrowing over of temperature interval of realization of the PG-mode to the effect, the same, extending the region of linear dependence ρ(Т) in ab-plane.

KEY WORDS: excess conductivity, hydrostatical pressure, YВaCuO single crystals, high temperature superconductivity, crossover, pseudogap state.