TARGET FRAGMENTATION OF ¹⁸¹Ta AND ²⁰⁹Bi BY RELATIVISTIC HEAVY IONS

I.D. Fedorets, S.S. Ratkevich

Full Text :   (1220 kB, Rus.) 

Abstract
Cross sections for the production of target fragments in the interaction of ¹⁸¹Ta and ²⁰⁹Bi with 43.80 GeV ¹²C, 58.40 GeV ¹⁶O, and 69.35 GeV ¹⁹F have been determined and used to deduce the isobaric and mass yield distributions. Comparisons between these data for relativistic heavy ions and those for relativistic protons have been used to test the hypotheses of factorization and limiting fragmentation. By combining cross sections from this experiment with data from literature, the empirical parameterization of the mass and charge yields of fragmentation products for arbitrary target-projectile combinations have been derived. The results are compared with Monte Carlo cascade-evaporation calculations and with the abrasion-ablation model. In addition the fragment mass distributions from the interactions of high energy ¹²C, ¹⁶O, and ¹⁹F ions and protons with ⁸⁹Y, ^natAg, ¹⁸¹Ta, and ²⁰⁹Bi are analyzed in terms of the universal finite size scaling low. The realization of this idea clears the way to a model independent classification of the various fragmentation mechanisms in terms of the scaling properties.

KEY WORDS: target fragmentation, heavy nuclei, mass and charge distributions, relativistic heavy ions, intranuclear cascade and abrasion-ablation model, scaling properties.

OBTAINING THE HIGH - PURITY CADMIUM FOR MICROELECTRONICS

G.P. Kovtun, A.P. Shcherban’

Full Text :   (500 kB, Rus.) 

Abstract
In the present work analysis of different purification methods of cadmium are carried out. The calculation of effectiveness the distillation and crystallization purification methods are made. The calculation data of the equilibrium k_0В and the limiting k_{0 limB} limB segregation coefficients of admixtures in cadmium under direction crystallization from the melt have been proposed. The experimental results obtaining high-purity cadmium combining the distillation in vacuum and the crystallization from the melt by Czochralski method are presented. It has shown the opportunity of use combination these methods for getting from primary cadmium cleanliness 3N the cadmium of classification more then 6N with high (80…90) % yield such purity.

KEY WORDS: high-purity cadmium, purification effectiveness, seperation coefficients, vacuum distillation, distribution coefficients, directional crystallization, Chochralski method, element analysis.

STUDY BY THE METHOD OF LAZER MASS- SPECTROMERY OF PROCESS REFINEMENT OF BERYLLIUM AT VACUUM DISTILLATION

V.M. Azhazha, V.D. Virich , K.V. Kovtun, N.S. Pugachov, I.V. Shpagin

Full Text :   (800 kB, Rus.) 

Abstract
The method of a vacuum distillation with application of an expedient refinement by condensation of steams beryllium on a surface heated to particular temperatures, receives beryllium by cleanliness more than 99,999 % of masses. Some features of erosion of impurities are discussed during a distillation beryllium, and also opportunity of severe clearing beryllium by a nonsingle distillation. The deduction is made that the rising of efficiency of processes refinement beryllium by a method of a vacuum distillation is caused by detailed selection of optimum regimens of realization of a distillation in checked requirements.

KEY WORDS: beryllium, refinement, vacuum distillation, distillation device, particular temperatures, optimization, mass - spectrometer ultimate analysis.

THE DYNAMICS OF DROP PHASE IN PLASMA OF LOW PRESSURE ARC DISCHARGE

А.А. Bizyukov, Е.V. Romashchenko, К.N. Sereda, А.D. Chibisov, А.Y. Кashaba

Full Text :   (420 kB, Rus.) 

Abstract
The possibility of evaporation or decrease in size of particular part of drops from cathode material in a plasma stream of vacuum arc due to their evaporation by charged particle streams in the mass transfer space was shown. It was shown that depending on initial sizes of the drops they can be cooled, heated to defined temperature or evaporated. The efficiency of drop phase evaporation grows with increasing plasma density. It was shown that the evaporation of drops in nonisothermal low pressure arc discharge plasma occurs mainly under effect of ion bombardment of drops.

KEY WORDS: arc discharge, drop phase, evaporation of drops, coating quality.

STABILITY OF THE HOMOGENEOUS ELECTRON PLASMA IN CYLINDRICAL SUPERCONDUCTIVE WAVEGUIDE

V.I. Lapshyn, V.I. Tkachenko, I.V. Tkachenko

Full Text :   (570 kB, Rus.) 

Abstract
Questions of stability of electron plasma in a cylindrical waveguide with ideally conductive walls are considered. The dispersion equation of an electron plasma ring is received and the surfaces determining areas of existence of stable solutions, for various parameters of the system and various values of an azimuth wavenumber l are constructed. It is shown, that with growth of l the relative part of stable oscillations of an electron plasma ring decreases. Also it was shown, that at small densities quasi-stable oscillations can exist.

KEY WORDS: non-neutral plasma, electron plasma ring, diocotron (slipping) instability.

COMPUTER SIMULATION OF ION DENSIFICATION OF NIOBIUM FILMS

Marchenko I.G., Chishkala A.V., Neklyudov I.M.

Full Text :   (850 kB, Rus.) 

Abstract
The paper is about the mathematical simulation of atomic-ion deposition of niobium films performed by the method of molecular dynamics. The ion flux was 10% of the total flux of deposited atoms, the ion energy was 200 eV. After thermal deposition of the film at a temperature of 300°K, to the thickness with which a stationary density is reached, the atomic-ion deposition of the film was followed. Ion action resulted in decreasing the density of the growing film and decreasing its roughness. The investigation shows that the ion densification occurs due to two physical mechanisms. The first mechanism is related with the film smoothing under ion bombarding. It leads to decreasing the quantity of "microcracks" below which pores take place. The second mechanism is the ion densification of films at the expense of knoking-in of proper interstitial atoms.

KEY WORDS: vacuum deposition, ions, computer simulation, niobium

FINE STRUCTURE OF THE M1 RESONANCE IN 23NA

A.S. Kachan, I.V. Kurguz, I.S. Kovtunenko, V.M. Mischenko

Full Text :   (370 kB, Rus.) 

Abstract
Gamma-decay of the resonance-like structure observed in the ²²Ne(p,g)²³Na reaction in the energy range E_p=0.8-2.5 MeV of accelerated protons was studied. Excitation function, g- ray spectra were measured for resonances at E_p = 851, 948, 1278, 1593, 1721, 1835 keV, wich composed this resonance-like structure. The M1 resonance built on the ground state and on the excited state 440 keV of ²³Na is identified. The position and total strength of the M1 resonance on the ground state is explained by taking into account pairing forces.

KEY WORDS: the ²²Ne(p,g)²³Na reaction, M1 resonance, M1-transition, pairing-energy, giant resonance.

INFLUEHCE OF ION IRRADIATION ON THE INCLUSIONS OF INTERMETALLIDES STABILITY IN Zr-V-Fe⁵⁷ ALLOYS

V.G. Kirichenkо, A.I. Kirdin, A.L. Pris, A.O. Harchenko

Full Text :   (370 kB, Rus.) 

Abstract
By using Conversion Electron Mossbauer Spectroscopy the investigation of subsurface layers of alloy Zr-V-Fe⁵⁷ on the base of zirconium at the initial annealing state and under heavy ion irradiation is carried out. At the initial state the compositional and structural homogeneity of alloy subsurface layers is observed. It's due to the migration absence of nanocrystalline particles of the iron containing intermetalic inclusions in subsurface layers of alloys under thermal annealing at temperature range 570° -1070°K. The phase composition of intermetallides in subsurface layers change occurs under irradiation of Zr-0,31%Fe-0,28%V at 300 K by Fe⁴⁺ ions with 2·10¹⁷ сm^-2 fluence. Irradiation leads to iron atom transition to crystalline phase Zr₃Fe. It's appear under follow-on isochronous annealing above 900°К.

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

INVESTIGATION OF ELECTRON BEAM AZIMUTH HOMOGENEITY IN A MAGNETRON GUN WITH A SECONDARY-EMISSION CATHODE

A.N. Dovbnya, V.V. Zakutin, N.G. Reshetnyak, N.A. Dovbnya, T.A. Kovalenko

Full Text :   (1000 kB, Rus.) 

Abstract
Azimuth homogeneity, electron beam parameters and dimensions in a magnetron gun with cold metallic secondary-emission cathode depending on magnetic field value and its distribution was studied. Azimuth homogeneity is an important beam parameter for generation of SHF-oscillations. Additional frequencies appear in the oscillation spectrum, and generation efficiency is increased when the azimuth homogeneity is disturbed. Such source is shown to form an electron beam with azimuth homogeneity of ±4%.

KEY WORDS: secondary emission, electron beam, azimuth homogeneity.

THE INVESTIGATION OF ANGULAR CHARACTERISTICS OF QUARTZ IONLUMINESCENCE RADIATION

Yu.K. Moskvitina, O.V. Kalantaryan, S.I. Kononenko, L.A.Marchenko, V.E.Filippenko

Full Text :   (330 kB, Rus.) 

Abstract
Experimental studies of the angular dependencies of quartz luminescence under hydrogen and helium ions bombardment are presented. The influence of different beam parameters on quartz indicatrix was studied. It is shown that nonirradiated quartz radiation indicatrix depends on incidence angle, species and energy of the bombardment ions. The quartz indicatrix form in the beginning of irradiation depends on absorbed dose amount and then it becomes unchanging. The possibility of using the obtained results for distant monitoring in construction elements of thermonuclear facilities was shown.

KEY WORDS: quartz, ionoluminescence, ion beam, hydrogen, helium, indicatrix, spectral method.

SECOND SOUND WAVE EXCITATION IN HE II BY PERIODIC ELECTRIC FIELD

V.D. Khodusov

Full Text :   (303 kB, Rus.) 

Abstract
The explanation of the experiments concerned the second sound wave excitation by the periodic electric field in superfluid helium is given. Due to the electrical induction, which appears in the case of the relative motion of the normal and superfluid components of the fluid and leads to the piroelectric effect, this electric filed causes an adiabatic modulation of the quasiparticle (phonon, roton) energy. It is shown when the frequencies of the electric field and the second sound wave are equal the resonance excitation of the waves take a place. The value of the piroelectric coefficient has been obtained.

KEY WORDS: second sound wave, superfluid Helium, phonons, rotons, forced oscillations, piroelectric effect.

RELAXATION PHENOMENA FOR ELECTRON IN CRYSTAL AND A GENERALIZATION OF CHAPMAN-ENSKOG METHOD

S.A. Sokolovsky, A.I. Sokolovsky, I.M. Chernenko

Full Text :   (350 kB, Rus.) 

Abstract
Relaxation of velocity and temperature of electron in crystal has been investigated. The problem was analyzed on the basis of kinetic equation for electron in equilibrium phonon bath with the help of the reduced description method that lead to a generalization of standard Chapman-Enskog method. It was shown that proposed by Landau method of investigation of relaxation phenomena in plasma corresponds to the simplest approximation in the framework of theory developed in the present paper.

KEY WORDS: relaxation phenomena in two component systems, generalized Chapman-Enskog method, Landau approximation.

COULOMB SUMS OF ⁴He FOR THE 3-MOMENTUM TRANSFERS NEAR 1 Fm^-1

A.Yu. Buki, I.A. Nen'ko, N.G. Shevchenko, I.S. Timchenko

Full Text :   (360 kB, Rus.) 

Abstract
The 8 spectra of electrons scattered by ⁴Не have been measured with the use of the electron linear accelerator LEA-300. The spectra have been measured in the wide energy transfers region at different incident energies (91 ? E₀ ? 262 MeV) and different scattering angles (55°? q ? 65°; q = 160°). The longitudinal and transverse response functions of ⁴He have been separated for effective 3-momentum transfers q = 0.9, 1.0, 1.2 fm^-1 from the received data. The experimental longitudinal response functions have been used to determine their zero moment values (the Coulomb sum). The received moment values have been compared with theoretical calculations.

KEY WORDS: electron scattering, lightest nuclei, response functions, Coulomb sum, nuclear forces.

STATIONARY REGIME OF EXCITATION OF ELECTROMAGNETIC WAVES IN PLASMA FILLED GYROTRON

S.Yu. Puzyrkov

Full Text :   (370 kB, Rus.) 

Abstract
The interaction of electron beam with eigenmodes of gyrotron and other similar devices is described by selfconsistent system of equations in particular derivatives. Usually this system is solved by step-by-step integration, starting from zero time. But in the most cases the subject of interest can be only stationary stage of system in the regime of saturation. The method of numerical solution witch is developed, allows to find this stationary solution directly with the minimum computation cost. The method is developed for the plasmafilled gyrotron, but can be applied for the vacuum gyrotron and other similar gyrodevices

KEY WORDS: gyrotron, plasmafilling, TE-mode, numerical methods, iterations.

DESCRIPTION OF ELECTROMAGNETIC FIELD IN MEDIUM BY INTENSITIES AND ONE-PHOTON DENSITY MATRIX

A.I. Sokolovsky, A.A.Stupka

Full Text :   (360 kB, Ukr.) 

Abstract
Description of transversal electromagnetic field in equilibrium medium by one-particle density matrix and intensities of the field has been proposed. The consideration was conducted in the framework of quasirelativistic quantum electrodynamics. Statistical operator of the system, Maxwell equations and kinetic equation for one-photon density matrix containing intensities of the field have been obtained. Relation between dispersion law, attenuation constant of electromagnetic waves and described by the kinetic equation characteristics of photons in the medium was established.

KEY WORDS: electromagnetic field, one-photon density matrix, the Bogolyubov reduced description method, the Peletminsky-Yatsenko model, characteristic frequencies and attenuation constants.

INVESTIGATION OF Na(Tl) SCINTILLATORS FOR POSITRON-EMISSION TOMOGRAPH AT HIGH GAMMA-QUANTUM INTENSITIES

 O.G. Konovalov,, S.T. Lukyanenko, A.A. Zybalov

Full Text :   (370 kB) 

Abstract
The characteristics of NaI(Tl) scintillators for positron-emission tomograph (PET) were investigated at high photon intensities and different photomultiplier tube (PMT) pulse durations in the single-channel mode as well as in the coincidence mode. Comparative analysis has shown that main characteristics of NaI(Tl) crystals are not inferior to those of Bi₄Ge₃O₁₂ crystals (BGO). The results of investigations evidence on the possibility for manufacturing a cost-effective PET on the basis of NaI(Tl) scintillators with the performances at a level of advanced PETs with BGO crystals.

KEY WORDS: photon, scintillator, positron-emission tomograph (PET), energy discrimination, energy and spatial resolution, random and true coincidences, counting rate, clipped pulse.

STRUCTURE OF SUPERMATRIX MODELS

S.A. Duplij, O.I. Kotulska

Full Text :   (90 kB, Rus.) 

Abstract
The main directions of supermatrix models theory are presented. The orthogonal polynomial method is described. Supermatrix models for various types of supermatrices are described. The statement about shape of model for triangle and antitriangle supermatrices forming semigroup are formulated.

KEY WORDS: matrix model, orthogonal polynomial, supermatrix, semigroup.

QUANTUM LINEAR SEMIGROUP STRUCTURE WITH REGULAR QUANTIZATION PARAMETER

S.A. Duplij, A.S. Sadovnikov

Full Text :   (350 kB, Rus.) 

Abstract
The possibility of construction of quantum plane with regular quantization parameter is considered. Two ways of generalization of quantum plane to ternary case are investigated. The first one is the simplest, whereas the second one uses the Ludde relation which do not disturb the quasitriangular bialgebra structure. The equations for generators of universal coacting for these quantum planes are derived, some special cases are discussed.

KEY WORDS: quantum plane, universal coacting, quasitriangular bialgebra, regularity, Hopf algebra, semigroup.

DECAYS OF B MESON, SUPERSYMMETRY AND POLARIZATION

S.A. Duplij, I.I. Shapoval

Full Text :   (350 kB) 

Abstract
In present work we discuss the usage of the set of B meson decays for testing Standard Model and its supersymmetric extensions. We select here the group of B decay modes, which are sensitive to new physics effects and collect some crucial data on branching ratios, showing the lack of correspondence for several orders of magnitude between supersymmetric model and Standard Model results, thus giving an undisputable evidence for supersymmetric extensions. Also the role of B meson system in confirmation of the factorization hypothesis is reflected here.

KEY WORDS: B meson, tests of Standard Model, supersymmetric extensions, branching ratios of B decays, polarization in B decays, factorization hypothesis.

LAGRANGIANS IN NONLINEAR MULTIGRAVITY MODELS

S.A. Duplij, A.T. Kotvytskiy

Full Text :   (350 kB, Rus.) 

Abstract
Nonlinear formulation of multigravity in the framework of weak coupled worlds is considered. The general form of multigravity lagrangians is analyzed. It is shown that when some paramenetrs satisfy special relations, this model tranforms into "classical" models, for indstance Pauli-Fiertz model. From general invariance principles and from requirement that interaction potential retain scalar one under metric tensor variations, the restriction of the shape of function describing universes interaction, is obtained. New shapes of invariant volume, which in case of bigravity in the limit transform into the standard Riemann geometry volume, are introduced.

KEY WORDS: multigravity, bigravity, lagrangians, nonlinear models, weakly coupled worlds.