PROSPECTS OF TUNGSTEN APPLICATION FOR THERMONUCLEAR FACILITY

O.A. Datsenko, A.I. Kondrik

Full Text :   (800 kB, Rus.) 

Abstract
The last achievements on elaborating production technology of tungsten alloys for their possible use as structural materials for divertor of fusion reactors (FR) have been reviewed. Different modeling designs of industrial FR and experimental reactor ITER have been considered. Thermomechanical and radiation-resistant properties of initial W and improved tungsten alloys were studied under influence of high temperatures, mechanical stresses as well as ionizing radiations being appropriated for divertor environment. A special consideration was given to the problem of induced activity of developing materials irradiated with high energy neutrons. Operating conditions for reprocessing of used materials were clarified. There were concluded about advantages and drawbacks of developed tungsten alloys, and the ways of their further upgrading have been outlined.

KEY WORDS: tungsten alloys, fusion reactors, divertor, induced activity, thermomechanical properties, ionizing radiations

SPECTRAL METHOD IN THEORY OF FAST CHARGED PARTICLES CHANNELING PHENOMENA IN A CRYSTAL

A.V. Kozlov, N.F. Shul’ga, V.A. Cherkaskiy

Full Text :   (430 kB, Rus.) 

Abstract
Quantum effects in interaction of particle and field can be essential attached to the channeling of fast charged particles in a crystal. There was shown possibility of using spectral method for defining quantum characteristics of interaction of particle with crystal in the presence of channeling process. On the base of this method there was developed procedure for defining eigenlevels of transversal motion in the presence of flat channeling and there was considered the problem of interaction between the wave packet and potential barrier, made up by potential of crystalline plane.

KEY WORDS: channeling, spectral method, tunneling, quantum effects in the presence of channeling.

ELECTRON MAGNETIC MOMENT AND THOMAS PRECESSION

Y.Y. Zanimonskiy, Yu.P. Stepanovsky

Full Text :   (360 kB, Rus.) 

Abstract
The spin precession of relativistic electron in the constant electromagnetic field is considered. The experimental investigation of this precession permits to measure electron magnetic moment with great accuracy. It confirms the correctness of Thomas and Moller approach to the study of Thomas precession. On this reason it is stated that recently suggested new formula for description of Thomas precession is wrong. The mathematical expression for Thomas rotation as the result of the sequence of some specifical three Lorentz transformations is obtained. Thomas rotation is different from Wigner rotation that is the sequence of three Lorentz boosts. Thomas rotation in contrast to Wigner rotation corresponds to correct Thomas and Moller formula for Thomas spin precession of relativistic electron. In calculation of Thomas rotation the notion of little Lorentz group is used.

KEY WORDS: Lorentz group, spin, magnetic moment, gyromagnetic ratio, precession.

TWO-PARAMETER MODEL FOR IRRADIATED POLYMER CONDUCTANCE VS ION BEAM FLUENCE

V.N. Bondarenko

Full Text :   (250 kB, Rus.) 

Abstract
General expressions describing the irradiated polymer layer specific electrical conductivity σ as a function of the ion beam fluence Ф are derived. Those expressions account for the radiation effect non-uniformity along ion path. The model predicts an increase of the irradiated polymer film general conductance with the ion energy enhancement, which agrees with previously published experimental data. Grounding on the experimental data analysis, a parameterization of σ(Ф) dependence at initial irradiation stage is proposed in form of power law σ(Ф)=CФ^b, where C is defined by ion energy and polymer sort.

KEY WORDS: polymers, electrical conductivity, irradiation, fluence, ions.

ELASTIC WAVE GENERATION IN SOLID BY PULSED BEAM OF NONRELATIVISTIC IONS

A.I. Kalinichenko, V.E. Strel’nitskij

Full Text :   (410 kB, Rus.) 

Abstract
Elastic wave generation in solid target is investigated in case of normal incidence of a uniform pulsed beam of nonrelativistic ions on flat surface of the target. It is shown that generated acoustic stress is the result of co-operative action of three mechanisms, i.e. the thermoelastic mechanism, the dynamic mechanism caused by momentum transfer, and the deformational one connected with nonthermal expansion of a target material. The equations characterizing elastic pulses generated in the framework of each of above-listed mechanisms are derived and their solutions for typical parameters of the ion beam are obtained. The terms of domination of one or another mechanism are formulated.

KEY WORDS: pulsed ion beam, solid target, acoustic waves, sound generation mechanisms, ion beam dosimetry

EQUATION OF TWO-FLUID HYDRODYNAMICS OF SUPERFLUID HELIUM WITH THE ACCOUNT OF ELECTRIC FIELDS

V.D. Khodusov, A.S. Naumovets

Full Text :   (270 kB, Rus.) 

Abstract
System of two-fluid hydrodynamics of superfluid helium with the account of electric field is obtained. These equations are obtained in kinetic approach using quasi-equilibrium distribution function of quasi-particles, which makes collision integral of quasi-particles vanish, and contains dependence on electric field by means of phenomenological parameter α. Using experimental data at temperature range of 1,4 - 2 K, where basic role plays roton hydrodynamics, the value of phenomenological parameter α, is obtained.

KEY WORDS: superfluid Helium, equations of two-fluid hydrodynamics, second sound, rotons, electric field

POSSIBILITY OF ^60M,GСО PRODUCTION AT THE NEUTRON GENERATOR

А.N. Dovbnya, E.L. Kuplennikov, V.A. Tsymbal, S.S. Kandybei

Full Text :   (190 kB, Rus.) 

Abstract
The work has been carried out in the framework of investigating the feasibility of medical isotope production at the NSC KIPT neutron generator. Detailed calculations of ^60m,gСо yield in the ⁵⁹Со(nγ)^60m,gСо nuclear reaction were made for the thermal neutron flux of 10¹² n×см^-2×c^-1. It has been shown that gamma-radiation activities ^60m,gСо in given target are higher than maximal dozes, which usually put into practice for number of diagnostic and therapeutic procedures in nuclear medicine.

KEY WORDS: neutron generator, thermal neutrons, cobalt, nuclear reaction, radioisotope, isomer, gamma-radiation, nuclear medicine.

INFLUENCE OF UNIDEALITY OF MAGNETIC FIELD OF SALO RECIRCULATOR BENDING MAGNETS ON PARAMETERS OF THE BEAM WITH TAKING INTO ACCOUNT HIGHER ORDERS OF CALCULATIONS

I.S. Guk, S.G. Kononenko, A.S. Tarasenko

Full Text :   (1560 kB, Rus.) 

Abstract
With using the results of measuring the parameters of EUTERPE bending magnets, the expected parameters of designed for recirculator SALO bending magnets are calculated. By the mathematical simulation method with taking into account the expected parameters of dipole magnets the influence of geometrical aberrations on parameters of beam in recirculator SALO in the point of its extraction with maximum energy was explored. The comparison of the results obtained with TRANSPORT code for various orders of calculations, with ones obtained by tracking with MAD-X code for an ideal and unideal magnetooptical system is carried out.

KEY WORDS: recirculator, electron accelerator, aberration, calculations order.

MOBILE POST OF PRELIMINARY OIL - FREE PUMPING FOR THE SOURCE OF X - RAY RADIATION NESTOR

A.N. Gordienko, V.G. Grevtsev, B.A. Lishenko, I.I. Karnaukhov,N.I. Mocheshnikov

Full Text :   (270 kB, Rus.) 

Abstract
The post of preliminary oil - free pumping has been designed and constructed for the generator of X - ray radiation NESTOR based on turbomolecular TPS - bеnch and forvacuum spiral SH - 110 pumps that will allow to provide the necessary pressure of start of the magnetic discharge pump. in the channel of the transportation and electron storage ring.

KEY WORDS: electron storage ring, ultrahigh vacuum, oil - free vacuum pumps, magnetic discharge pump, generator γ - quantum, back Compton effect.

IMPEDANCE OF ASYMMETRIC CAPACITOR FILLED BY RF INDUCTIVELY COUPLED PLASMA

D.V. Rafalskyi, S.V. Dudin

Full Text :   (350 kB, Rus.) 

Abstract
In this paper simple analytic model of RF impedance of asymmetric capacitor filled by low-pressure RF inductively coupled plasma is developed. Results of experimental measurements of the asymmetric capacitor impedance in the system with 250 mm diameter gas-discharge chamber are present. Comparison of the experimental data with the results of theoretical modeling shows possibility of not only estimations but for exact prediction of the plasma capacitor impedance using the developed model. The proposed model of the plasma capacitor impedance may be useful for RF circuit's design of plasma technological systems with combined RF inductive-capacitive discharge.

KEY WORDS: RF ICP, RF plasma impedance, plasma capacitor.

NORMAL MODE OF THE LONGITUDINAL COMBINED DISCHARGE IN LOW PRESSURE NITROGEN

V.A. Lisovskiy, N.D. Kharchenko

Full Text :   (650 kB, Rus.) 

Abstract
This work is devoted to investigation of a normal longitudinal combined discharge when DC and RF voltages are applied to the same electrodes. Previously it was shown that longitudinal combined discharge can burn in three possible modes. In this work it is shown that when we apply the RF voltage to the combined discharge burning in the third mode (DC discharge perturbed by the RF electric field) there is almost no influence on the DC current magnitude and the area occupied by the discharge spot at the "cathode". However after transition to the second mode with the RF voltage growth, a fast increase of the DC current and broadening of the discharge spot is observed. It is shown that in the normal combined discharge as well as in the DC discharge, a transition pressure range exists, where j/p² is not the constant value but decreases with the discharge current increase. The radial profiles of the discharge current density in normal and abnormal modes of longitudinal combined discharge and the axial profiles of the discharge were experimentally investigated, and modeling of the combined discharge using program Oopic Pro was made. It is shown that both normal and abnormal combined discharges can burn in three modes, and have two peaks of the glow intensity near the "anode" which are formed in the second mode.

KEY WORDS: normal mode, radio-frequency capacitively coupled discharges, DC discharges, combined dischardes, low pressure, nitrogen.

INFLUENCE OF ANNEALING ON PROPERTIES AND STRUCTURE OF THE DEFORMED HAFNIUM

M.P. Starolat, A.A. Vasilyev, S.P. Stetsenko, R.V. Azhazha, K.V. Kovtun

Full Text :   (1420 kB, Rus.) 

Abstract
The hafnium deformed rolling on 30 % at a room temperature, at the subsequent annealing at temperatures to 1123К softens, and its plasticity increases. Return of mechanical properties, proceeding from change of electro resistance and dislocation structure, proceeds in two stages. At annealing lower 800К return is related to annihilation and a leaving of dot flaws to sinks, and above 800К with redistribution of dislocations and recrystallization.

KEY WORDS: hafnium, deformation, annealing, properties, structure

INFLUENCE OF IONIC AND LASER TREATMENT ON STEELS SURFACE

V.G. Kirichenko, V.N. Leonov

Full Text :   (1420 kB, Rus.) 

Abstract
The results of research of structure - phase transformations in alpha-iron and steels after impulsive laser and ion influence on surface are presented. The irradiating by ions of nitrogen and the titan of ferritic steel 20 causes creation in surface layer (up to 0,3 mkm) nitride of iron and phase iron - titanium. Pulsing laser effect on a surface of an alpha-iron causes formation in a near- surface layer of the initial ferromagnetic material of a significant amount of an austenitic paramagnetic phase (up to 30 %). At an irradiation on a surface of iron along with creation of a paramagnetic phase the stepped structures of wavy type caused by processes of melting-down and superfast refrigerating of surface layer have been created.

KEY WORDS: ionic and laser irradiation, ferritic steels, phase transformations

THE STRUCTURE OF NANOMETRIC FILMS

V.G. Kirichenko, O.V. Kovalenko

Full Text :   (350 kB, Rus.) 

Abstract
The results of research of processes of forming of films of Ba - hexaferrite and Bi-Gd garnet obtained by the methods of ion-beam deposition on of gadolinium- gallium garnets are presented. As a result of an ion-beam deposition from data of Mossbauer spectroscopy of conversion electrons the amorphous paramagnetic films of Ba - hexaferrite are formed. Phase composition is inhomogeneous on the thickness of tapes. The ion-beam deposition Ba - hexaferrite films resulted to formation of amorphous paramagnetic layers which transformed into magnetic ordering state under thermal ageing. The deposition of bismuth - gadolinium garnet films also conducted with formation of amorphous paramagnetic layers and later crystallization of magnetic ordering films under thermal ageing and ion implantation. The ion implantation of Не⁺ ions with energy E=26 keV and fluence Ф=2,25×1014 см^-2 is the most effective and therefore rotated the axis of easy magnetization into film plane.

KEY WORDS: thin films, conversion electron Mossbauer spectroscopy, spectrometry of Rutherford backscattering, element and phase composition.

OPTICAL DETECTION OF MOSSBAUER α-IRON SURFACE SPECTRUM

V.G. Kirichenko, S.V. Eremin

Full Text :   (600 kB, Rus.) 

Abstract
In this work propose a method of optical detecting nuclear ? - resonant spectra of dispersion at the analysis of a surface of pure iron and DSO-iron. It is revealed that the gas category in proportional detectors is accompanied highlighting optical photons. The technique of registration of the optical spectra connected with the gas category in proportional detector MSCE is developed. Simultaneously received spectra are compared: electronic spectra of dispersion and the spectra received by means of registration of an integrated optical luminescence, accompanying the gas category. It is revealed that optical (photon) spectra of return dispersion are registered in a case when electrons, radiated of blankets deformed foils gland. It proves to be true comparison of photon spectra with the received experimental dependences of relative intensity of lines of a spectrum of dispersion on a hade γ - quanta.

KEY WORDS: M?ssbauer spectroscopy, conversion electrons, gas-discharge detector.

EFFECT OF LABILE OXYGEN REDISTRIBUTION ON TEMPERATURE DEPENDENCE OF PSEUDOGAP IN OXYGEN DEFICIENT НОВА₂СU₃О_7-δ SINGLE CRYSTALS

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

Full Text :   (240 kB, Ukr.) 

Abstract
Effect of annealing at room temperatures on excess conductivity of НoВa₂Сu₃О_7-δ single crystal with deviation from oxygen stoichiometry. It is shown that in the process of five days annealing there is substantial expansion of linear interval of dependence ρab(Т) and narrowing of temperature area of the pseugap regime. The exess 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, НoВa₂Сu₃О_7-δ single crystals, pseudogap state.

COMPUTER SIMULATION OF THE EVOLUTION OF COPPER FILMS STRUCTURE UNDER PVD

I.G. Marchenko, I.I. Marchenko

Full Text :   (4000 kB, Rus.) 

Abstract
The molecular dynamics method was used to investigate the processes of the structure evolution of FCC metal films at deposition temperature from 50 to 500K. It has been established that the change in the surface structure layer reveals a nondiffusion behavior and is caused by the collective atomic motion in clusters. The investigations were carried out on the temperature dependence of the dislocation-induced coalescence (DIC) phenomenon consisting in the fcc cluster growth as a result of fcc cluster number decreasing because of the motion of surface Shockley dislocations. It is demonstrated that the observed phenomenon takes place in the whole temperature range investigated. As the temperature decreases, the role of DIC in the structural self-organization of deposited FCC films increases. Consequently, the onset of DIC stage shifts towards the higher values of occupancy.

KEY WORDS: films, physical vacuum deposition, computer simulation, copper.