CALCULATION METHODS OF SPECTRAL AND SPECTRAL-ANGULAR DISTRIBUTIONS OF RADIATION OF HIGH ENERGY ELECTRONS IN EXTERNAL NONUNIFORM FIELDS

V.P. Lapko, N.F. Shul'ga

Full Text :   (255 kB, Rus.) 

Abstract
The quasi-classical formulae for spectral and spectral-angular radiation densities by relativistic electrons in an external nonuniform field taking into account a recoil and nondipolity of radiation were investigated. The method of numerical calculations under these formulae is expounded. Their limiting cases such as dipole approximation, radiation from a corner trajectory and a constant field approximation is considered. The comparison of exact and approximate calculations under these formulae on an example of radiation of high energy electrons in a field of a single atomic string of crystal is carried out.

KEY WORDS: quasi-classical approximation, constant field approximation, numerical calculation, approximation of corner trajectory, coherent radiation in crystal.

GUIDING CENTER DISTRIBUTION FUNCTION IN TOROIDAL MAGNETIC FIELD WITH ONE RESONANT STRUCTURE

N.A. Azarenkov, O.A. Shyshkin, R. Schneider, Yu.L. Igitkhanov

Full Text :   (3195 kB, Eng.) 

Abstract
Analytical expression for the guiding center distribution function in the toroidal magnetic field of HELIAS stellarator with the one resonant structure was obtained as a solution of the drift kinetic equation. This expression gives possibility to treat analytically the critical task for the modern fusion devices, e.g. to estimate the particle transport in 3D plasma edge configurations. One resonant structure means that in a vertical cross-section of the magnetic field configuration we observe one island chain, which possesses the pure separatrix. Additional perturbations that cause additional magnetic islands and stochastic layers are not taken into account. Analytical treatment of the problem is done for the model in which the electric field is neglected. The solution of the drift kinetic equation is assumed to be the sum of sinc₁ and cosc₁ harmonics, where c₁ represents the dependences on toroidal and poloidal angle variables, "wave" numbers of perturbation, perturbation frequency and time. It is shown, that in accordance with the model, the cosc₁ harmonic vanishes and the solution, which consists of only the one sinc₁ - harmonic, is enough to present changes in distribution function caused by a resonant structure of the magnetic filed. As a numerical example the tungsten ion guiding center distribution function is considered.

KEY WORDS: HELIAS, stellarator, guiding center equations, guiding center distribution function, magnetic field resonance, electric field potential.

THERMOMECHANICAL ACTION OF SLOW NEUTRONS ON BIOGENIC MATERIALS

A.I. Kalinichenko, V.V. Tovstiak

Full Text :   (274 kB, Rus.) 

Abstract
Formation of small overheated regions - thermoelastic peaks (TEPs) - near to points of scattering of neutrons with energy from 0.5 to 5 keV in biogenic materials, due to energy loss of recoils is theoretically investigated. On basis of computer simulation of process of the energy transfer from the recoil to atoms of the material and the relaxation processes account, the origin time and the lifetime, the size and the shape of TEPs formed by different recoils are determined. The possibility of thermodynamic description of the matter state in TEP is considered. Overheat temperature and thermoelastic pressure in TEP are determined. Classification of TEPs by geometrical characteristics, overheat and overpressure in them is carried out. An impact mechanism of pulsed pressure generation caused by recoil momentum transfer to TEP material is investigated. Characteristics of a zone of biological action around TEP where the material undergoes irreversible changes are considered.

KEY WORDS: neutron, elastic scattering, recoil, ion range, thermoelastic peak, destruction.

BASIC LAWS OF BOUNDARIES EFFECTS FOR THE ABSORBED DOSE DISTRIBUTION OF ELECTRONS IN THE HETEROGENEOUS MATERIALS

I. Kaluska, V.T. Lazurik, V.M. Lazurik, G.F. Popov, Yu.V. Rogov, Z. Zimek

Full Text :   (1330 kB, Eng.) 

Abstract
The anomalies of the absorbed dose distribution of electrons near the boundary of contacting materials at orientation in parallel with incident electron beam were predicted by computer simulation with use the ModeRTL software. Dosimetric experiments were performed on radiation-technological line to validate the theoretical predictions. Heterogeneous targets were irradiated by scanning electron beam with electron energy 10 MeV on moving conveyer. The basic laws predicted by simulation methods on curves of depth-dose distribution of electrons near the boundary of contacting materials with different densities and/or atomic numbers were experimentally confirmed. The physical models for explanation of observed boundaries effects are considered in the report.

KEY WORDS: absorbed dose, electron beam, boundary effects, simulation, experimental validation.

PROPERTIES OF HIGH-SPIN FERMION INTERACTION CURRENTS

Yu.V. Kulish, E.V. Rybachuk

Full Text :   (177 kB, Ukr.) 

Abstract
The problem of power divergences in theory of high-spin massive fermion (J>1/2) interactions is investigated. The conventional approaches have two sources of the power divergences: 1) the factors like to p_m / M in the propagators of the high-spin fermions (p_m and M are the momentum and the mass of the high-spin fermion, respectively); 2) the products of the p_m and some constants in the components of the spin-tensor for interaction current j_m1...ml. It is shown that in consistent theory the spin-tensors for the interaction current j_m1...ml must be traceless and their convolutions with the momentum p and g - matrixes must vanish. Therefore the contributions of the factors of p_m / M -type to the high-spin fermion propagators must vanish. As the equations for the high-spin fermion interactions are the system of heterogeneous differential equations, the field and current spin-tensors must have the continuous partial derivatives of 2J+2 and 2J+1, respectively. In result, the current components must include the form factors, which provide the decreasing of these components at least as |p_m| ^- (2J+1) with |p_m| ® ¥.

KEY WORDS: high spin, fermions, divergences, differential equations.

THE PRESENT STATE OF THE ART OF PRODUCING VARIOUS-PURPOSE RADIONUCLIDES AT ACCELERATORS AND REACTORS

A.N. Dovbnya, N.P. Dikiy, O.V. Nemashkalo, A.I. Tutubalin, B.L. Uvarov, A.G. Shepelev, B.I. Shramenko, L.D. Yurchenko

Full Text :   (230 kB, Rus.) 

Abstract
The review presents scientific analysis of the current status of radionuclide (RN) production and application. A particular attention was paid to the problem of RN production at charged particle accelerators in comparison with RN production at reactors. The data on the use of RN for nuclear medicine, agriculture and engineering are compared. In addition to the evidence found in the surveys devoted to the topic, we have used the information contained in the IAEA International DataBase "International Nuclear Information System" (INIS) for the period from 1970 to 2003. Analysis was performed with the data files include more than 16000 sources of information, about 30 key words and notions were used. The paper contains the information about RN production by different methods - at reactors, accelerators of heavy particles (ions, protons), and electron accelerators, RN separation and refining, as well as, the information about distribution of publications in the fields of application, by years, countries and kinds of publications. The conclusions about trends of research on the problem under consideration are drawn.

KEY WORDS: radioisotopes, accelerators, reactors, nuclear medicine, science of science.

INFLUENCE OF DEFORMATION ON THE g-DECAY OF FINE STRUCTURE OF THE ANALOGUE d_5/2 RESONANCE IN THE ²²Ne(p,g)²³Na REACTION

A.N. Vodin, V.Yu. Korda, L.P. Korda, O.A. Lepyoshkina, S.A. Trotsenko, I.V. Ushakov

Full Text :   (160 kB, Rus.) 

Abstract
Experimental studies of the g-decay of four components of fine structure of the analogue d_5/2 resonance in ²³Na (a parent level with E* = 2,517 МeV in ²³Ne) observed in the ²²Ne(p,g)²³Na reaction were carried out at Е_p = 1623, 1721, 1803 and 1835 keV. The decay schemes of the given resonances were constructed, mixing ratios were found for primary g-transitions and their partial g-widths Г_gi were determined. The rates of analogue-antianalogue M1 transitions are found to be slow in comparison with estimations on the shell model with surface d-forces. It is connected with deformation of ²³Na nucleus. It is shown that collective effects connected with the excitation of core polarisation states and the giant M1 resonance take part in the g-decay of the analogue resonance.

KEY WORDS: ²²Ne(p,g)²³Na reaction, analogue resonance, g-decay, probability of M1 transition, core polarization state, giant M1 resonance.

INFLUENCE OF THE LAW OF REFLECTION OF PARTICLES ON EFFECT OF A PLASMA ECHO FROM BOUNDARY

A.A. Vodyanitskii

Full Text :   (156 kB, Rus.) 

Abstract
In paper the nonlinear spatial echo is considered from the external current flowing on playing role of the grid antenna and placed on some distance from boundary of plasma, smaller than length of free run of the charged particles. Expressions for a field of the echo are received, allowing to judge about dependence of intensity of this field from velocity of a share of particles which are reflected from boundary aptly by mirror. Results can find application in development of ways of communication through dense layers of plasma and are interesting as an illustration of a nonlinear echo from one source of a extern current.

KEY WORDS: reflection of particles from boundary, spatial nonlinear echo in plasma, resonance.

E1 DECAY OF ISOBAR ANALOG 1f_7/2 AND 2p_3/2 STATES IN ²⁷Al NUCLEUS

A.N. Vodin, V.Yu. Korda, L.P. Korda, O.A. Lepyoshkina, S.A. Trotsenko, I.V. Ushakov

Full Text :   (140 kB, Rus.) 

Abstract
The g-decay of 1f_7/2 and 2p_3/2 analogue resonances observed in the ²⁶Mg(p,g)²⁷Al reaction are studied at Е_p = 2294 (7/2^-), 2324 (7/2^-) and 2022 (3/2^-) keV. The decay schemes of the given resonances were constructed, mixing ratios d were found for primary g-transitions and their partial g-widths Г_gi were determined. The rates of analogue-antianalogue M1 transitions are found to be slow in comparison with estimations on the shell model with surface d-forces. It is shown that polarization effects connected with virtual excitation of the giant E1 resonance take part in the g-decay of the analogue resonances.

KEY WORDS: ²⁶Mg(p,g)²⁷Al reaction, analogue resonance, g-decay, probability of E1 transition.

RELAXATION IN PHONON SYSTEMS OF SUPERFLUID HELIUM CAUSED BY THREE-PARTICLE PROCCESES

Yu.A. Kitsenko, V.A. Slipko

Full Text :   (186 kB, Rus.) 

Abstract
Starting from hydrodynamic Landau Hamiltonian we obtained an expression for typical rates of three-phonon relaxations in isotropic phonon system of superfluid He II at saturated vapor pressure. This expression is correct for all energies where three-phonon processes are allowed by conservation laws. The obtained expression has been generalized on a case of any pressure up to 19 bar. Limit cases have been analyzed and they were compared with results of previous researches. The rates of phonon interaction with anisotropic phonon system have been calculated at saturated vapor pressure and in case of high pressures.

KEY WORDS: phonon, isotropic system, anisotropic system, relaxation rate, three-particle process.

THE DEVELOPMENT OF ALLOY FOR FUEL CONTOUR OF MOLTEN-SALT REACTORS

V.M. Azhazha, Yu.P. Bobrov, O.F. Vanzha, P.N. V’yugov, T.G. Yemlyaninova, K.V. Kovtun, S.D. Lavrinenko, M.M. Pylypenko, V.I. Savchenko, A.D. Solopikhin, S.P. Stetsenko

Full Text :   (1415 kB, Ukr.) 

Abstract
The results of choice, developments and alloys making for to circulation contour of fuel salt of molten-salt reactors, and also researches of structure, chemical composition and some properties of obtaining alloys are given. Analysis of basic physical properties of construction materials gave advantage to nickel alloys. The optimum admission of alloying elements was picked up. Employing the physical methods of refining (electron beam melting, distillation, annealing in high vacuum et al.) were got the high pure initial alloy components. Using method of induction melting in inert atmosphere were made alloys of two compositions. The alloy straps were obtaining by rolling at high temperature. The properties of obtaining alloys were got. The influence of deformation and heat treatment on mechanical properties and structure of alloys were learned. The researches results can recommend the obtaining alloys as material for fuel contour of molten-salt reactors.

KEY WORDS: alloy, nickel, molybdenum, chromium, molten-salt reactor, structure, heat treatment, mechanical properties.

OBTAINING HIGH - PURITY ZINC COMBINING THE DISTILLATION AND CRYSTALLIZATION PURIFICATION METHODS

G.P. Kovtun, A.P. Shcherban, V.D. Virich

Full Text :   (182 kB, Rus.) 

Abstract
In the present work the analysis and comparison of different purification methods of zinc have been made. The calculation the distil-lation process of zinc has been made. The calculation results of the equilibrium k_0B and the limiting k_{0 limB} segregation coefficients of admixtures in zinc under direction crystallization from the melt have been proposed. On the basis of these calculations and analysis of binary constitutional diagrams the behaviour classification of admixtures in zinc under directional crystallization with conformity to a periodic elements system has been made. The experimental results obtaining high-purity zinc combining the distillation in vac-uum and the crystallization from the melt by Czochralski method have been presented. It has shown the opportunity of use combina-tion these methods for getting from primary zinc cleanliness 4N the zinc of classification 6N with high (85…90) % yield such purity.

KEY WORDS: high-purity zinc, segregation coefficients, vacuum distillation, directional crystallization, classification of admix-tures, mass - spectrometry, element analysis.

AMORPHIZATION OF THE NANOCRYSTALLINE INCLUSIONS OF INTERMETALLIDES IN Zr-Fe⁵⁷ ALLOYS UNDER ION IRRADIATION

V.G. Kirichenkо, A.L. Pris

Full Text :   (1205 kB, Rus.) 

Abstract
By using X-ray spectroscopy analysis and Conversion Electron Mossbauer Spectroscopy the investigation of structure and subsurface layers of alloy Zr-Fe⁵⁷ on the base of zirconium in the initial ageing state and under heavy ion irradiation is carried. In initial state the compositional and structural heterogeneity of alloy subsurface layers is discovered. On the base of experimental data the 3-dimensional diagrams which connect the compositional and structural heterogeneity of subsurface layers with temperature and time of thermal treatment of deformed alloys are designed. The migration of nanocrystalline particles of the ferrouscontaining intermetallic inclusions in subsurface layers of alloys under thermal aging in temperature range 570-1070K is conditioned by high mobility of grain boundaries in zirconium matrix. Under irradiation of Zr-0,31%Fe and Zr-0,63%Fe alloys at 300K by Fe⁴⁺ ions with 2·10¹⁷ сm^-2 dose the phase composition of intermetallides in subsurface layers change. Irradiation leads to iron atom transition from crystalline phase Zr₃Fe to amorphous phase. Under isochronous ageing at 370-970К the crystallization of amorphous intermetallic inclusions and iron atoms transition into crystalline phase Zr₃Fe with initial structure have taken place.

KEY WORDS: zirconium alloys, surface, intermetallic inclusions, segregation, irradiation.

RECEIVING AND EXAMINATION OF COATS ON A BASIS Ti-Al-N PRECIPITABLE FROM STREAMS OF VACUUM ARC METAL PLASMA

V.M. Beresnev, V.T. Tolok, V.I. Gritsenko, A.G. Chunadra, A.I. Fedorenko, I.A. Savchenko

Full Text :   (255 kB, Rus.) 

Abstract
Coats Ti-Al-N from two independent adjustable evaporators by the method of a vacuum deposition was obtained. Changing relations between components of streams, it is possible to change a phase composition of coats. The influence of the content of aluminum in a coat Ti-Al-N on wear hardness hard alloyed of cutting plates is explored at handling doped steels. Is shown, that coats Ti-Al-N with the content of aluminum from 10 up to 20% (mass) ensures pinch of stability of cutting plates in comparison with initial in 3,8 times in explored field of handling modes. The obtained coats have high thermo stability in comparison with coats TiN.

KEY WORDS: a vacuum-arc method, Ti-Al-N coats, thermostability.

INFLUENCE OF THE SOLIDIFICATION CONDITIONS ON THE STRUCTURE OF NICKEL BORIDE ALLOYS

V.Ye. Semenenko, T.A. Kovalenko, M.V. Tretyakov

Full Text :   (710 kB, Rus.) 

Abstract
Bicrystal specimens with regular structure by unidirected solidification. are obtained The specimen is a borid single crystal with interstitial nickel phase. The analysis of cooperative growth of quasieutectic nickel-boron alloys in the nucleation process and stationary solidification is made. The morphological composite characteristics are determined by the crystallochemical nature of the base phases of the eutectic. The data obtained on growth parameters which influence on the regularity and stability of the structure up to melting temperature is given.

KEY WORDS: bicrystals, quasieutectic alloys, composite, microstructure, dispersion, heterophase systems, colonies, coagulation, particles.

ENERGY DISTRIBUTIONS OF ELECTRONS IN STAINLESS STEEL BOMBARDED BY FAST IONS

S.I. Kononenko, V.P. Zhurenko, O.V. Kalantaryan, V.T. Kolesnik, V.I. Muratov, D.N. Shevzova

Full Text :   (109 kB, Eng.) 

Abstract
The results of experimental investigations of secondary electron emission energy distributions and yields induced by 1¸2 MeV H⁺ and He⁺ ion impact on stainless steel are presented. The projectiles were obtained from Van de Graff accelerator. It is shown that for all projectiles the electron energy distribution functions measured have piecewise power-law dependences with different power indices on various electron energy intervals. The corresponding power indices and electron yields are presented.

KEY WORDS: fast ion, electron distribution function, electron emission, stainless steel, spherical analyzer, electron yield.

THE HIGHVACUUM PLANT SET FOR MANUFACTURING OF THIN METAL FILMS

A.N. Morozov, V.I. Zhurba, V.G. Kulish, V.N. Belan

Full Text :   (210 kB, Rus.) 

Abstract
You can see a highvacuum plant set for reception of thin metal films, where the basic constructional element is the cooled electronic-beam evaporator. The cryogenic system of pumping out allows to receive the background pressure in the working chamber about2×10^-7 Pa or 5×10^-6 Pa in depending on usage of liquid hydrogen or nitrogen. While evaporate films pressure in the chamber of the evaporator grows, but thus does not exceed ~5×10^-6 Pa or >2×10^-5 Pa depending in used coolant. Preliminary underpressure in the experimental chamber up to pressure ~3×10^-5 Pa is created with turbomolecular and magnetdischarge pumps. On the given installation have been received a film of a nickel, a titan and a palladium. The analysis of a chemical compound films, executed with the help of Auger-electronic spectroscopy has shown, that the suggested installation provides process evaporation thin films metals with the contents of gas impurity no more than 2×10^-4 аt.%.

KEY WORDS: highvacuum plant set, electron beam evaporation, metal films, contamination gases.