FORMATION OF RESIDUAL NUCLEI WITH MEDIUM MASS NUMBERS IN THE REACTION OF RELATIVISTIC ¹²C IONS WITH YTTRIUM AND SILVER

I.D. Fedorets, S.S. Ratkevich

Full Text :   (3000 kB, Rus.) 

Abstract
Target residues from the reaction of 43.8 GeV ¹²C ions with yttrium and silver nuclei have been studied with activation techniques. By combining cross sections from this experiment with data from literature, the empirical parametrization of the mass and charge yields of fragmentation products for arbitrary target-projectile combinations have been derived. The results of this study and the empirical description are compared with Monte Carlo cascade-evaporation calculations and with the abrasion-ablation and unified multifragmentation-evaporation nuclear reactions models. The electromagnetic dissociation of ⁸⁹Y target nucleus was inferred from measurements of cross section for the one-neutron removal reaction. The experimental cross section in excess of the estimated nuclear contribution is generally well described by use of the Weizsacker-Williams method for calculating the electromagnetic dissociation contribution.

KEY WORDS: target fragmentation, mass and charge yields, relativistic heavy ions, factorization, electromagnetic dissociation.

POSSIBILITY TO DETECT COSMIC PARTICLES AND NEUTRINO OF SUPER-HIGH ENERGIES IN ATMOSPHERIC AIR AND CONDENSED MEDIA USING MAGNETOINDUCTIVE METHOD

V.M. Kartashev, V.E. Kovtun, O.K. Minko, Yu.P. Poltoratskaya, E.S. Shmatko, I.I. Zaliubovskii

Full Text :   (1900 kB, Eng.) 

Abstract
A possibility was considered to detect cosmic particles and neutrinos of super-high energies using the electromagnetic induction of the excess electrons in an extensive air shower (EAS) as well as in showers occurring in condensed media (ice, halite). Electromagnetic induction caused by the showers occurring in the mentioned media was calculated. The structure of a detector based on this principle has been offered. The detector response was calculated for different distances from the shower axis. The detector energy threshold was estimated to be ~10¹² eV for the showers in condensed media, and ~10¹⁶ for the EAS.

KEY WORDS: extensive air shower, excess electrons, electromagnetic induction shower, induction detector.

BORN AND EIKONAL APPROXIMATIONS IN THE TRANSITION RADIATION THEORY

N.F. Shul’ga, V.V. Syshchenko, V.G. Syshchenko

Full Text :   (1600 kB, Rus.) 

Abstract
The process of transition radiation of relativistic electrons in non-uniform media is considered. The method of description of this process based on the equivalent photons method and the eikonal approximation of the wave mechanics is proposed. The formulae for the spectral-angular density of the transition radiation that permit to examine the radiation in the case when the dielectric permittivity depends on more than one coordinate are obtained in this approximation. The comparison of the basic results obtained in Born and eikonal approximations of the transition radiation theory is carried out. The ranges of validity of these results are determined. The formulae obtained are applied to the analysis of the transition radiation process on the uniform plate and on the fiber-like target.

KEY WORDS: transition radiation, Born approximation, eikonal approximation, equivalent photons, inhomogeneous media.

SIGNATURES OF QUANTUM CHAOS IN QUADRUPOLE SURFACE OSCILLATIONS OF NUCLEI

V.P. Berezovoj, Yu.L.Bolotin, V.A. Cherkaskiy

Full Text :   (3000 kB, Rus.) 

Abstract
Quadrupole surface oscillations of atomic nuclei in liquid drop model represent a paradigm for quantum chaos. Depending on parameters of the nucleus corresponding potential can have one or several local minima. In the latter case the mixed case is observed, which is general situation for multi-well two-dimensional potentials. We investigate the quantum manifestations of classical stochasticity in the energy levels statistics, wave functions structure and wave packets dynamics in the mixed state.

KEY WORDS: quantum chaos, mixed state, spectral method, quadrupole oscillations of nuclei.

COMMON PROPERTIES OF THE CHARGING FORM FACTOR HARD COUPLED SYSTEM IN CONSERVATION STRUCTURAL CURRENT APPROACH

Yu.A. Kasatkin, I.К. Kirichenko, A.P. Korzh, О.D. Ptashniy

Full Text :   (1200 kB, Rus.) 

Abstract
Gauge invariant objects of type gauge strings and gauge invariant "star" in which translations in charging space are coordinated with requirements of transmitting invariance in configuration space, allow to enter into consideration of vertex and the amplitudes of processes adequate to interaction gauge of a field with compound fields of a matter without attraction лагранжева of a formalism. The correct account of redistribution of a charge between fragments in the field of interaction is solved on a background of the requirement covariance. The received amplitudes of processes take into account not only the contribution from topmost functions of strong interaction, but also their derivatives. It results in the balanced account in amplitude as one-partial mechanisms brought by function of pulse distribution of components, and to the account of multiparty mechanisms through a derivative from it, that corresponds to the effective account mesons exchange currents. The opportunity of suppression in amplitude charging forms of the factor of the contribution of multiparty mechanisms in relation to the contribution one-partial is shown due to a choice of a kind of a relative 4-pulse.

KEY WORDS: covariance, gauge invariance, vertex function, charge form factor.

TWISTORIAL SPINNING PARTICLE

 V.G. Zima , S. Fedoruk

Full Text :   (1600 kB, Rus.) 

Abstract
It is established a correspondence of twistor formulation and formulation in real space-time for massive and massless particles of arbitrary spins (helicities). It is obtained the equations of twistor transformations realizing the correspondence of twistor description and description of spinning particle in terms of the real space-time variables. It is constructed integral transformation of the twistor field obtained in prime quantization of a spinning particle in the twistor formulation. Space-time spin-tensor fields obtained after the transformations reproduce descriptions of massive spinning particle in terms of - and -component fields and Fierz-Pauli, Bargman-Wigner and Rarita-Schwinger fields.

KEY WORDS: Penrose's twistors, spinning particle, conformal symmetry, twistor transformation.

ATMOSPHERIC PRESSURE PULSED PLASMA POLYMER SURFACE MODIFICATION

S.A. Goloviatinski

Full Text :   (1500 kB, Rus.) 

Abstract
Dielectric surface plasma activation is carried out by using of pulsed high voltage RF-discharge at atmospheric pressure. This gas discharge creates the non-equilibrium plasma on the treated surface. Process times are in 0,01-0,1 sec range. Developed device generates the gas discharge in the form of long plasma "string" and can be used for an uniform and high effective treatment of large dielectric surfaces. The results of polymer surface activation by wettability modification and surface chemical analyses are discussed.

KEY WORDS: activation, surface energy, dielectric, atmospheric pressure plasma, RF, high voltage gas discharge, pulsed treatment.

MODES OF ELECTROMAGNETIC FIELD IN EQUILIBRIUM PLASMA

A.I. Sokolovsky, A.A. Stupka

Full Text :   (900 kB, Ukr.) 

Abstract
On the basis of the Bogolyubov reduced description method and quasirelativistic quantum electrodynamics statistical operator of the system of electromagnetic field and equilibrium plasma has been found. Calculations were conducted in the Hamilton gauge up to the second order of a perturbation theory in interaction. Hamilton-Maxwell equations were obtained and their wave solutions were investigated. A method of construction of an effective Hamiltonian of electromagnetic field in the medium was proposed. On the basis of this Hamiltonian quasiparticles of electromagnetic field in equilibrium plasma (dressed photons and plasmons) were introduced.

KEY WORDS: the Bogolyubov reduced description method, the Hamilton gauge, the Peletminsky -Yatsenko model, equilibrium plasma, effective Hamiltonian, quasiparticles.

COMPUTER SIMULATION OF VACUUM DEPOSITION OF NIOBIUM FILMS

I.G. Marchenko, I.I. Marchenko, I.M. Neklyudov

Full Text :   (1500 kB, Rus.) 

Abstract
The paper presents the study of the process of Nb film deposition at room temperatures. The dynamics of changing in the surface relief of growing films was investigated by the method of molecular dynamics. It has been found, that in the process of film growth on the flat surface there forming are "microgullies" which lie along the crystallographic directions <100>. It is shown that these surface structures can relax with formation of an edge dislocation of a ½<111> type in the bulk of a material. The change of the atomic film density with relation to the bulk density is determined. It is established that the decrease of the density is caused by the formation of micropores lying in correlation along the directions <100> in the planes {110}.

KEY WORDS: films, vacuum deposition, computer simulation, niobium.

A GENERALIZED CHAPMAN-ENSKOG METHOD IN THEORY OF ELECTRON DIFFUSION IN CRYSTAL

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

Full Text :   (780 kB, Rus.) 

Abstract
Diffusion of an electron in crystal was studied on the base of a kinetic equation obtained without assumption about a weak non-uniformity of state of the system. A generalized Navier- Stockes approximation was developed and a correction for diffusion coefficient was calculated. It was emphasized that weak consistency of the Burnett approximation results in standard approaches with experiment can be related with neglecting by influence of non-uniformity of the system on interaction of its particles. For enough small gradients of parameters, which describe state of the system, contributions of the generalized Navier-Stockes approximation can have a bigger order then the Burnett terms.

KEY WORDS: strong non-uniform states, generalized Chapman-Enskog method, non-classical polynomials.

REFLECTION OF SPIN WAVES ON A DEFECT OF ANISOTROPY

A.N. Kuchko, S.V. Vasil’ev

Full Text :   (770 kB, Rus.) 

Abstract
In a continuum approximation a theoretical study is conducted of spin waves propagation process in infinite easy exes magnetic with model one-dimensional defect of constant of magnetic anisotropy. The energy transmission factor of spin waves in case of exact solvable model of defect is calculated. In the framework of theory of perturbation a the linear amendment to transmission factor was calculated. This type of defect may by used as a high-pass filter or a direction filter of spin waves.

KEY WORDS: Landau-Lifshitz equation, parameter of Spin-Density, spin waves, reflection, defect of anisotropy.

MATERIAL DENSITY MEASUREMENT WITH COMPTON SCATTERING METHOD USING

V.D. Afanasyev, S.A. Pismenetskiy, V.B. Pyshkin, V.G. Rudychev, V.I. Teslenko-Ponomarenko, I.S. Timchenko

Full Text :   (870 kB, Rus.) 

Abstract
The experimental test has been described for a possibility of determination of material density by Compton scattering method. The measurements were carried out with the scintillation detectors (dosimeters) and through the use of linac bremsstrahlung; as tested materials cellulose, plexiglass, concrete, Al and Fe were taken. Coordinate resolution was calculated of cylindrical detector equipped with long collimator, which was chosen to limit tested element of model volume. The dependence was achieved of dose rate of scattered at a scattering angle of 45° on scattering density. The difference between experimental and calculated results is less than 30%. The performed measurements have shown that such method may be used for determination of material density and revealing of light substances.

KEY WORDS: linac bremsstrahlung, element of model volume, Compton scattering, density determination.

LOCALIZATION OF CARBON ATOMS IN A CRYSTAL LATTICE OF NICKEL

V.M. Shershnev, N.A. Skakun, P.A. Svetashov

Full Text :   (660 kB, Rus.) 

Abstract
The carbon location in the monocrystal solution Ni - 0,18 at.%C enriched with the ¹³C isotope has been determined by the resonant nuclear reaction ¹³C(p,g)¹⁴N (Е_res = 1,7476 MeV, Г_g = 70 eV), excited with protons channeling along axes <110>, <100> and <111> close-packed by the nickel atoms and along the plane (100). Strong changing in the g-yield from the reaction has been observed in the narrow interval of angles (±0,4°) between the proton beam direction and the crystallographic one. It has been shown that the carbon atoms occupy the octahedral voids in the nickel at concentration 0.18 at. % and at room temperature.

KEY WORDS: channeling, nuclear reaction, nuclear resonance, location of impurity.

THE MEASUREMENT METHOD OF ANGULAR DISTRIBUTION OF ELECTRON BREMSSTRAHLUNG AT GAMMA QUANTUM ENERGY ABOVE 6 MeV

S.A. Kalenik, V.I. Kasilov,  V.V. Kirichenko , K.S. Kokhnjuk, L.A. Makhnenko, V.I. Noga,  P.M. Rjabka , A.A. Khomich

Full Text :   (760 kB, Rus.) 

Abstract
Beams of g-quantums with energy above 6 MeV (higher than a threshold of uranium photofission) are necessary for realization radioactive waste diagnostics by the photon method. For their reception on linacs of electrons it is necessary use of photon converters Bremsstrahlung is well described by Shiff formulas, but in a case with thick targets they are not applicable. The measurement method of angular distribution of bremsstrahlung submitted in this paper allows to measure angular distribution of g-quantums with energy above 6МeV. The experiment for realization of measurement method with use LINAC-300 is carried out. Similar experiment with help GEANT 3.21 has been simulated. Results of mathematical simulation and physical experiment are well coincide.

KEY WORDS: fissionable materials, bremsstrahlung, angular distribution, experiment, diagnostics, simulation, converter.

COMPUTER MODELING OF PROTON CHANNELING IN CRYSTALS

N.A. Skakun, V.M. Shershnev, N.A. Shlyakhov

Full Text :   (800 kB, Rus.) 

Abstract
The program of computer modeling of proton channeling trajectories in the line of atomic planes in a crystal has been developed. The redistribution of the proton flux density in a plane channel of the Ni - 0,18ат.%С monocrystal solution has been studied. To investigate orientation effects at channeling of positively charged particles, we offer the approach based on the use of radiation yields from resonant reactions on the nuclei of impurity atoms occupying certain positions in a crystal. It has been shown that the g-yields of the ¹³C(p,g)¹⁴N resonance nuclear reaction essentially depend on the energy of channeling protons.

KEY WORDS: channeling, nuclear reaction, nuclear resonance, location of impurity.