GENERAL ANALYSIS OF POLARIZATION EFFECTS IN THE REACTION γ+d→d+π+π. I. SINGLE-SPIN ASYMMETRIES

G.I. Gakh, A.P. Rekalo, A.G. Gakh

Full Text :   (157 kB, Eng.) 

Abstract
A general analysis of expressions for polarization observables in the reaction of coherent photoproduction of pair pseudoscalar mesons on deuteron target, γ+d→d+π+π, has been performed. This analysis does not depend on the details of the reaction mechanism since it based on general symmetry properties of the electromagnetic interaction with hadrons. Expressions for the following polarization observables have been obtained: the asymmetries due to the linear or circular polarization of photon beam, the asymmetries caused by the vector or tensor polarized deuteron target. The experimental situation when scattered deuteron and one of the produced pions are detected in coincidence has been considered. The expressions for the single-spin asymmetries in the reaction γ+d→d+π+π have been also derived.

KEY WORDS: polarization, cross section, photoproduction, asymmetry, electron, deuteron.

ENERGY DISTRIBUTION OF THE DIPOLE TRANSITION STRENGTHS IN ⁹⁰ZR

I.D. Fedorets, S.S. Ratkevich

Full Text :   (480 kB, Rus.) 

Abstract
Absolute values and the energy dependence of the radiative strength functions for dipole transitions from the compound-nucleus states to ⁹⁰Zr final levels are determined from the resonance-averaged partial cross sections for the (р, γ)-reaction on ⁸⁹Y, measured in the proton energy range of 2.17 – 5.0 MeV. The data so obtained are compared with predictions of various models. The best description for E1- transitions is achieved on the base of the models accounting for the dependence of the strength function on the γ-ray energy, temperature, and nuclear shell structure. The Lorentzian form leads to total-cross-section values for the (р, γ)-reaction on ⁸⁹Y markedly in excess of not only experimental data but also the result of calculations within other theoretical models.

KEY WORDS: proton capture, partial cross section, compound nucleus, radiative strength function, statistical theory, nuclear structure, dipole transition strengths, giant dipole resonance, reaction mechanism

A NEW HAMILTONIAN FORMALISM FOR SINGULAR LAGRANGIAN THEORIES

S.A. Duplij

Full Text :   (120 kB, Eng.) 

Abstract
We introduce a version of the Hamiltonian formalism based on the Clairaut equation theory which allows us a selfconsistent description of systems with degenerate (orsingular) Lagrangian. A generalization of the Legendre transform to the case when the Hessianis zero is done using the mixed (envelope/general) solutions of the multidimensional Clairaut equation. The corresponding system of equations of motion is equivalent to the initial Lagrange equations, but contains "nondynamical" momenta and unresolved velocities. This system is reduced to the physical phase space and presented in the Hamiltonian form by introducing a new (non-Lie) bracket.

KEY WORDS: Legendre transform, Hessian, multidimensional Clairaut equation,non-Li ealgebra, Poisson brackets

LAVRENTJEV’S ELECTROMATGNETIC TRAPS

S.A. Vdovin

Full Text :   (282 kB, Rus.) 

Abstract
Experimental results of electromagnetic plasma confinements are summarized in this article. Electromagnetic traps are distinguish from other plasma confined systems in principle. In these traps electrons are confined by sharp-angle magnetic field, and ions - by electrical field of volumetric electrons charge. Electromagnetic plasma confinements have been studied in the main by the author's of idea O.A. Lavremt'ev, and co-workers. Early experiments used simple model of electromagnetic traps - spindle cusps. Experiments confirmed main principles of electromagnetic plasma confinement. Later more compound systems were constructed: toroidal quadrupole at Kurchatov institute, Moscow and linear set of ring cusps at KIPT. Many years standing electromagnetic plasma confinement show that under certain conditions in the boundary region of electromagnetic traps where the density is low drift instabilities may occur. According to the theory of anomalous transport plasma in electromagnetic traps that instabilities cause anomalous electrons energy transport across magnetic field. But those instabilities do not bring to catastrophe and at larger volumes of field-free plasma influence of instabilities on transport electrons across magnetic field become unimportant. In the linear set of ring cusps transport rate of electrons something like the classical rate. Computation builds on near- classical transport of electrons found that electromagnetic trap - reactor has acceptable engineering requirements. Electromagnetic traps could be used for neutron generator and heavy ion sources.

KEY WORDS: plasma, magnetic field, electric potential, electromagnetic trap, thermonuclear reactor.

EFFECT OF GAS MOLECULES DISSOCIATION ON BURNING RF DISCHARGE IN LOW-PRESSURE AMMONIA

V.A. Lisovskiy

Full Text :   (250 kB, Rus.) 

Abstract
This work is devoted to the experimental study of the effect of the dissociation of ammonia on burning RF capacitive discharge. It is shown that for each ammonia pressure there is a certain threshold RF voltage below which the degree of dissociation is less than 3%, while at higher RF voltages dissociation degree increases up to 30%. Increased dissociation of NH₃ accelerates the growth of discharge current with radiofrequency voltage. RF discharge at both low and high degree of dissociation is in the low-current α-mode, as all the dissociation products of ammonia have higher ionization potentials than NH₃.

KEY WORDS: radiofrequency capacitive discharge, low-current mode of the discharge, dissociation, ammonia, low pressure.

IN SITU GAMMA -SPECTROMETRY OF RADIOACTIVE MATERIALS

D.V. Kutniy, S.A. Vanzha, G.V. Zyma, V.A. Mykhailov, A.V. Mazilov, I.G. Goncharov

Full Text :   (380 kB, Rus.) 

Abstract
The basic advantages and technical opportunities of gamma -spectrometry in "real- time" mode with software ISOCS are viewed. Experimental researches on measuring activity of radioactive sources using gamma-spectrometer on the basis of scintillation detector NaI (Tl) and software ISOCS are carried out. It is shown, that gamma-spectrometer system with software ISOCS is the best alternative existing for today in Ukraine to similar equipment for solving the key problems of an express quantitative analysis of radioactive materials.

KEY WORDS: gamma -spectrometry, software ISOCS, scintillation detector, radionuclide, activity.

FIRST CONCEPT OF COMPACT INSTRUMENT SIDRA FOR MEASUREMENTS OF PARTICLE FLUXES IN THE SPACE

O.V. Dudnik, M. Prieto, E.V. Kurbatov, S. Sanchez, T.G. Timakova, V.N. Dubina, P. Parra

Full Text :   (710 kB, Eng.) 

Abstract
The concept of the compact instrument SIDRA for measurements of energetic charge particle fluxes and the first results of laboratory tests of the separate units are presented. The SIDRA instrument consists of one detector unit based on the high purity silicon PIN (ΔE, E) and rapid scintillation detectors, of analogue & digital signal processing units, and of one secondary power supply module. Different objectives - scientific and also applied ones such as measurements of absorbed dose rates can be achieved in the outer space with the help of the SIDRA device. Main features and parameters of the device such as weight, dimensions, power consumption as well as some electrical characteristics are presented.

KEY WORDS: silicon detector, charge particle, scintillator, Digital Processing Unit, data base, spacecraft, computer simulation

STRUCTURAL INHOMOGENEITY OF A GARNET’S THIN FILMS

V.G. Kirichenko, O.V. Kovalenko

Full Text :   (710 kB, Eng.) 

Abstract
Тhe results of study of yttrium - iron garnet (YIG) thin films structure after ion-beam deposition on gadolinium gallium garnet substrate are presented. According to the data of Rutherford backscattering spectrometry of the gadolinium gallium garnet substrate structure and films layer-by-layer analysis leads us to the conclusion about variable elemental composition of substrate and YIG films. The amorphous paramagnetic films of YIG are formed on substrate surface. The iron and yttrium content is increased on the depth of films.

KEY WORDS: iron-yttrium garnet, thin films, element and phase composition, amorphization, crystallization, magnetically phase.

REPRESENTATIONS, QUIVERS AND THEIR SUPERSYMMETRIC GENERALIZATIONS

S.A. Duplij, G.Ch. Kurinnoj

Full Text :   (280 kB, Rus.) 

Abstract
The paper deals with properties and some applications of quivers in mathematical physics. Initially, we study the graph sand for them the adjacency matrix and incidence matrix are defined. Then the path semigroup and free semigroup algebra of this semigroup are considered. The possible treatment of quiver in category theory is given, and the path algebra over a number field is constructed. The importance of quiver to visualize different relationships between the studying modern models of elementary particles is emphasized. Further the quiver over the rings and quiver representations are defined, initially asadiagram over a finiteset, then asa representation of congruences. Next, specify the application of quivers in computer science, and also superquivers are briefly considered.

KEY WORDS: graph, path semigroup, cycle, congruence, ring, module, homomorphism, exactsequence, Dynkin diagram

DIELECTRIC PROPERTIES OF WATER ELECTROLYTE SYSTEMS. IV. FREQUENCY 75.5 GHZ

A.A. Asheko, S.A. Batulin

Full Text :   (480 kB, Rus.) 

Abstract
Researches of complex permittivity on the frequency 75.5GHz in the temperature range 271-353K of mono- and polyelectrolyte water systems were made. The studies were conducted with the help of original computer-based experimental stand reflective type. Systematic errors in determining the values of complex permittivity do not exceed 0.5% for the real part of the complex permittivity and 0.8% for the imaginary part. Character of the obtained temperature and concentration dependence of the relaxation indicates the nature of the interaction of electromagnetic waves from these systems.

KEY WORDS: dielectric spectroscopy, the complex dielectric constant, dipole relaxation, water, electrolyte.

STUDY OF QUARK-GLUON PLASMA AT LOW ENERGIES

V.S. Trubnikov

Full Text :   (480 kB, Rus.) 

Abstract
This overview paper deals with several aspects of Quark-Gluon Plasma study (QGP). We discuss some experimental effects considered to be the QGP signatures, in particular strangeness enhancement, suppression of J/ψ meson production, suppression of high Pt particle production and jet quenching. Special attention is paid to the two modern experiments dedicated to QGP formation at low energies.

KEY WORDS: high-energy physics, QCD, quark-gluon plasma