GENERAL ANALYSIS OF POLARIZATION OBSERVABLES IN THE REACTION  e⁻ + d → e⁻ + π⁰ + d

A.G. Gakh

Full Text :   (155 kB, Eng.) 

Abstract
A general analysis of expressions for polarization observables in the reaction of coherent pseudoscalar meson electroproduction on deuteron has been derived. This analysis does not depend on details of reaction mechanisms since it based on general symmetry properties of the electromagnetic interaction with hadrons. Expressions for the following polarization observables have been obtained: the asymmetries caused by the vector or tensor polarized deuteron target, the spin correlation coefficients which describe the dependence of the cross section on deuteron target polarization and longitudinal polarization of the electron beam and the asymmetry due to the longitudinal polarization of the electron beam. The experimental situation, when final deuteron and scattered electron are detected in coincidence, has been considered.

KEY WORDS: polarization observables, cross section, asymmetry, electron, deuteron, meson electroproduction.

FORMING OF THE DIFFERENT SPECTRAL CHARACTERISTICS OF BREMSSTRAHLUNG RADIATION FROM 10 MEV ELECTRONS

V.T. Lazurik, S.A. Pismenetskiy, V.G. Rudychev, D.V. Rudychev

Full Text :   (292 kB, Rus.) 

Abstract
Approach is proposed for the comparison of characteristics of bremsstrahlung radiation (BR) in the energy range, where Compton scattering is dominant. Parameters of the converter, which provides maximum of BR in the 3-5 MeV electron energy range, are determined. Some particularities were investigated of BR under the different coincidence angle of electrons and different converter material at E=10 MeV. It was shown the average energy of BR depends sufficiently both a coincidence angle of electrons and the material of the converter. Both the angles and converter material have been found when the BR spectrum from 10 MeV electrons is the similar as 4 MeV spectrum under normal coincidence of electrons. The use of the particularities investigated of BR makes it possible an achievement of dual energy method of radiography on one electron accelerator to 8-10 MeV energy.

KEY WORDS: bremsstrahlung radiation, spectra, converter material, coincidence angles of electrons, criteria of adequateness, dual energy.

ACOUSTIC RESPONSE OF PLATE AT DIFFERENT INPUT MODES OF RADIATION BEAM ENERGY

A.I. Kalinichenko

Full Text :   (284 kB, Rus.) 

Abstract
Generation of acoustic oscillations in plate at pulsed irradiation by penetrating particle beam in regimes of single pulse or periodic sequence of radiation pulses is theoretically investigated. Absorption or dissipation of generated oscillations is taken into account. Possibility of increase of generation efficiency of oscillations due to use of radiation sources with resonant frequency of pulse sequence is analyzed. Features and threshold of brittle fracture of the plate are determined depending on plate thickness and radiation pulse characteristics.

KEY WORDS: radiation beam, thermoacoustic oscillations, sound absorbtion, resonance, fracture

THE INFLUENSE OF RADIFTION AND TEMPERATURE ON DIFFUSION OF RADIONUCLIDES ²²NA FROM TUFF AND CLINOPTILOLITE

N.P. Dikiy, A.N. Dovbnya, E.P. Medvedeva, I.D. Fedorets, N.P. Khlapova, N.S. Lutsay, Yu.V. Lyashko, D.V. Medvedev, D.S. Bakay

Full Text :   (237 kB, Rus.) 

Abstract
The complex approach of studying of migration radioactive nuclides in conditions which model behaviour of the spent fuel at a burial place in geological structures is developed. Properties of tuff and clinoptilolite - the inorganic materials having sorption opportunities are investigated. The influence of radiation and temperature on leaching and level transformation of structure in researched samples were studied by photon activation analysis and IR-spectrometry. It is shown, that in the modified samples the high level crystallinity and phases composition is kept. Intensity of leaching of radionuclides Na for tuf, irradiated tuf and clinoptilolite in depending of time are investigated. Distinction in character leaching sodium from natural and irradiated tuff, and also distinction in speed leaching radioactive nuclide from tuff and clinoptilolite is revealed depending on time.

KEY WORDS: tuff, klinoptilolite, gamma - activation analysis, leaching of radionuclides, IR-spectroscopy, crystallinity.

FORMATION OF SPATIALLY PERIODIC ELECTRON BEAMS IN A MULTI-BEAM MAGNETRON GUN WITH SECONDARY-EMISSION CATHODES

A.N. Dovbnya, V.V. Zakutin, N.G. Reshetnyak, N.I. Ayzatsky, T.A. Kovalenko, V.P. Romas’ko, I.A. Chertishchev, G.I. Churyumov, N.A. Dovbnya

Full Text :   (531 kB, Rus.) 

Abstract
Experimental studies have been made into formation of a four-beam electron flow in the electron-optical system comprising magnetron guns with cold metal secondary-emission cathodes. The beam formation spread time was investigated as a function of magnetic field amplitude and distribution. The mode of electron-current bunches formation has also been studied. The results of investigations suggest the conclusion on a possibility of creating rectangular cathode matrices based on magnetron guns with secondary-emission cathodes and rod anodes.

KEY WORDS: magnetron gun, secondary-emission cathode, electron beams, multi-beam flow, cathode matrix

ANALYSIS OF THE FEATURES OF DIFFERENT METHODS OF RADIOACTIVE WASTE TRANSMUTATION

R.P. Slabospitskij

Full Text :   (275 kB, Rus.) 

Abstract
Using the results of our earlier studies of the transmutation of radioactive waste main elements irradiated with fast and epithermal neutron effectiveness of different transmutation methods is analyzed. It is studied the features of radioactive waste transmutation in the fast reactors, the accelerator driven systems (ADS), consisting from the fast reactor and charged particles (protons or electrons) accelerator and facilities with D-T fusion for neutron energy 14 MeV. Possible using of these facilities for transmutation of both transuranic elements and fission products is analyzed. The advantages and disadvantages of these facilities for transmutation of transuranic elements and fission products in the cases of their simultaneous and separate irradiation are discussed. Hybrid systems consisting of ADS with hard neutron spectrum and thermal reactors with soft neutron spectrum are the most promising systems, as they can be used for transmutation of both the transuranic elements and fission products, i.e. the entire spectrum of nuclear waste.

KEY WORDS: transmutation, radioactive wastes, fast reactor, electro-nuclear system

STRUCTURE AND PROPERTIES OF NI-CR COATINGS

А.А. Drobyshevskaya, V.М. Beresnev, D.L. Alontseva

Full Text :   (271 kB, Rus.) 

Abstract
The results of investigation of structure and properties of coatings on the basis Ni-Cr obtained by a method of plasma detonation with the subsequent melting by a plasma jet are presented. The differences in a phase composition and in mechanical properties before and after duplex treatment are established. After melting by a plasma jet the coatings have high hardness, wear resistance and stability to corrosion in seawater. The improvement of properties of coatings as a result of duplex treatmentis reached both due to of phase transformations, and due to of smoothing of a surface roughness and homogenization of surface layer at melting.

KEY WORDS: duplex treatment, coating, phase analysis, nanoparticles, hardness.

EFFECT OF REDISTRIBUTION OF LABILE OXYGEN ON THE PSEUDOGAP STATE IN UNTWINED YВА₂СU₃О_7-δ SINGLE CRYSTALS

Z.F. Nazyrov, R.V. Vovk, M.A. Obolenskii, A.A. Zavgorodniy, K.A. Kotvitskaya

Full Text :   (173 kB, Ukr.) 

Abstract
Effect of annealing at room temperatures on excess conductivity of untwined YВa₂Сu₃О_7-δ single crystal with small deviation from oxygen stehiometry are investigated. It is shown, that in the process of annealing at room temperatures about four days are results to the significant expansion of the temperature interval of pseudogap anomaly existence in ab-plane. The excess conductivity submits exponential temperature dependence in the wide temperature interval. The temperature dependence of pseudogap satisfactorily described by BCSh-BEK theoretical model

KEY WORDS: annealing, labile oxygen, redistribution, YВa₂Сu₃О_7-δ single crystals, pseudogap states.

FORMATION OF MULTYSCALE STRUCTURES IN ZIRCONIUM ALLOYS

V.G. Kirichenko, A.B. Shevtsov

Full Text :   (310 kB, Ukr.) 

Abstract
The investigation by nuclear gamma-resonance of zirconium-based alloys with transition metal additions after thermo mechanical treatment was carried out. The influence of additions and their size factors on the c/a relation of Zr matrix was founded. Under increasing of ageing temperature the coagulation of second phases and segregation of phase particles on the surface have taken place. The building 3D-diagrams in С (at %Fe57) - Т (K) - t (h) coordinates allowed to carry out the analysis of phase particle migration and boundary grain migration processes. In alloys of Zr - Fe -Та systems the development of inclusions segregation is beginning from 870-900 K and this process developed on various size multiscales - nanometrical and micrometrical. The initial base of multiscale structures, which formed under polymorphic, deformation and corrosion processes on various hierarchical scaling levels - nanometrical, micrometrical and macroscopic scales was created.

KEY WORDS: M?ssbauer spectroscopy, conversion electrons, surface. multiscale structures

THE FATIGUE OF POLYCRYSTALLINE HAFNIUM IN TEMPERATURE REGION 77-650 K

K.V. Kovtun

Full Text :   (415 kB, Rus.) 

Abstract
In this research we studied the dependency of fatigue strength of hafnium on the temperature. It was found out that at the temperature range from 77 to 650 K the fatigue strength increases with a temperature decrease. Moreover, it was shown that the fatigue cracks originate on the stable sliding bands inside the grains. The further development of the cracks occurs on the borders of adjacent grains as well as due to transcrystallite grain separation. However, in hafnium, in contrast to zirconium, no twins were found under the alternate deformation and the main deformation mechanism during the fatigue test was a dislocation sliding.

KEY WORDS: hafnium, fatigue strength, destruction mechanisms

PECULIARITIES RECRYSTALLIZATION COPPER OF HIGH PURITY

V.E. Semenenko, D.V. Lysan, T.O. Kovalenko

Full Text :   (823 kB, Rus.) 

Abstract
The kinetics of recrystallization of high purity copper doped trace. Samples were subjected to cold plastic deformation with subsequent controlled annealing. Define the texture of the samples, the mechanism of microstructure formation and the activation energy of recrystallization. The analysis of influence of sulfur on collective recrystallization is carried out. The interrelation collective recrystallization and activation energy is established. The results obtained allow us to estimate the influence of grain boundaries on the temperature of the output of copper from a state of abnormal plasticity.

KEY WORDS: copper, texture, migration of grains, recrystallization, microimpurity, dislocations.

THE LIMITING DISTRIBUTION COEFFICIENTS OF LOW-SOLUBLE IMPURITIES IN METALS

A.P. Shcherban’

Full Text :   (196 kB, Rus.) 

Abstract
The characteristic of effective - кВ, equilibrium - к0В and limiting impurity distribution coefficients (CD) in metals and theirs determination methods are given. The description of proposed determination method of the limiting CD impurities к0 limВ which have trace solubility in metals are presented. A new determination approach of the limiting CD impurities is consist in combination of theoretical calculations of к0 limВ with respect to thermodynamic parameters and mathematical analysis only of state diagrams liquidus curve. The application results of suggested determination method к0 limВ in such metals like Cd, Zn and Te are reduced.

KEY WORDS: metals, impurities, refining, distribution coefficients, oriented crystallization, state diagrams, solubility

STATIONARY STATES AND SELF-SIMILAR DYNAMICS OF GAS BUBBLES IN LIQUID MEDIA AT REDUCING THE EXTERNAL PRESSURE

B.V. Borts, S.F. Skoromnaya, V.I. Tkachenko

Full Text :   (182 kB, Rus.) 

Abstract
A system of equations describing the first-order phase transitions in various media with the formation of gas bubbles is obtained. The convective terms in the space of bubble size, which convert the kinetic equation for the bubbles in a divergence form, with the addition of term proportional to the bubbles distribution function in a liquid is taken into account in the proposed system of equations. The steady state of the gas bubbles in the liquid and its self-similar dynamics at a time-decreasing external pressure under the power law is investigated.

KEY WORDS: phase transition, gas bubbles, convection terms, the equilibrium state of gas bubbles, self-similar dynamics.

THE QUANTUM TUNNEL EFFECT FROM THE POINT OF VIEW OF QUANTUM MECHANICS AND CLASSICAL PHYSICS

A.М. Kondratenko, V.V. Kostenko, V.V. Shkoda

Full Text :   (126 kB, Eng.) 

Abstract
Parallel analyses of matter penetrating a barrier are analyzed, one using electrodynamics, the other using quantum mechanics. Mathematical operations are performed to show the identical nature of the phenomena of reflection above the barrier and of penetration of the barrier in quantum mechanics and in classical electrodynamics. It is shown that, in reality, the tunneling effect is not a "purely quantum phenomenon".

KEY WORDS: quantum mechanics, barrier, penetration, reflection, tunnel effect.