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 EPAS'98
Elementary Processes in Atomic Systems
 
  On the14-15th October 1998 in the
Institute of Electron Physics ,
Ukr. Nat. Acad. Sci. a scientific conference
  dedicated to the 80th anniversary of the Ukrainian National Academy of Sciences, was held.
At the conference the original reports on the following issues were presented:
 

·   elementary processes and phenomena, stimulated by interaction of electron, ion, atomic and molecular beams of low and medium energy with each other and with condensed matter;

·   elementary processes and mechanisms of lasing excitation in gas lasers;

·   photo nuclear reactions, radiation strength of materials and devices, technologies of nuclear physics in diagnostics and curing of complicated diseases .

  The Proceedings contain the materials concerning the most up-to-date directions of scientific research:

 

 

FOUNDATION AND DEVELOPMENT OF ACADEMIC SCIENCE

IN THE FIELD OF PHYSICS IN TRANSCARPATHIA

(To the 80 th anniversary of the Ukrainian National Academy of Sciences)

A.N. Zavilopulo, V.A. Kelman

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

An attempt is made to trace the foundation and development of academic science in the field of physics in Transcarpathia from the foundation of Uzhgorod State University to the present time. The role of the first founders of the academic science in Transcarpathia (V.O. Shkoda-Ulyanov, I.P. Zapesochny, Yu.M. Lomsadze, D.V. Chepur) is emphasized. The process of formation of the first independent academic institute – the Institute of Electron Physics, Ukr. Nat. Acad.Sci. – is described.

FORMATION AND ANNEALING OF RADIATION DEFECTS

IN PARATELLURITE SINGLE CRYSTALS

Yu.M. Azhniuk

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

The results of optical absorption studies of TeO 2 crystals, irradiated at room temperature by up to 10 18 cm -2 10-MeV electrons and subsequently annealed to 575 K, are discussed. The dependence of exciton-phonon interaction parameter in TeO 2 on the electron beam fluence is obtained. The irradiation-induced near-edge broad (2.5—3.5 eV) absorption band is shown to be related to oxygen vacancies, annealing at 475–525 K.

THE STUDY OF SERUM OF BLOOD PHOTOLUMINESCENCE

SPECTRA FOR DIAGNOSTIC OF LIVER DISEASES

O.Yu. Bandurin

Uzhgorod State University,

46 Pidhirna St., Uzhgorod 294000, Ukraine

The technique is developed and the photoluminescence spectra of serum of blood of practically healthy people as well as of those ill with hepatitis, cirrhosis and cancer of liver are studied. This method is shown to enable the liver pathologies to be determined differentially, the disease degree to be revealed and the nominated treatment effectiveness to be monitored.

RESONANCE PROCESSES IN THE EXCITATION OF METAL IONS

BY SLOW ELECTRONS

A.N. Gomonai

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

On the basis of the results of experimental investigation of mono energetic electron interaction with metal ions the role of resonance phenomena due to the formation and decay of autoionizing states in excitation and dielectronic processes has been analyzed. The influence of the relativistic and correlation effects on the resonance processes has been found. The substantial effect of subvalence 3d 10 shell on the valence electrons excitation has been revealed.

MULTIPHOTON SPECTROSCOPY OF NEUTRAL YTTERBIUM

O.I. Gomonai

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

Three-photon ionization spectrum of ytterbium has been studied in the 440-448 nm wavelength range. The wavelength dependence for Yb + ions reveals seven maxima resulting from two- and three-photon excitation of bound and autoionizing states of ytterbium atom, the corresponding data being not yet available from the references.

ABSORPTION SPECTRA OF OXIDE GLASSES IRRADIATED
WITH HIGH-ENERGY ELECTRONS

A.V.Gomonnai

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

The effects of high-energy (5–10 MeV) electron irradiation upon optical absorption and photoluminescence spectra (300–800 nm) of optical oxide glasses (KU-1, F-1, K-8) are reported. The obtained results have shown the introduction of modifiers in SiO 2 to decrease the glass radiation strength, the dependences of the optical parameters on the irradiation dose, energy and temperature being determined by the defects, formed by non-bridge oxygen atoms.

ENERGY STRUCTURE AND LUMINESCENT PROPERTIES

OF Cu-DOPED Li 2 B 4 O 7 CRYSTALS

B.M. Hunda

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

An automated setup and the corresponding software for performing complex studies of deep local levels by TSL technique is elaborated. Luminescent properties and energy position of trapping levels of copper-doped lithium tetraborate poly- and single crystals are investigated. A new model of Li 2 B 4 O 7 energy structure is suggested.

ONE-PHOTON EMISSION COMPUTER TOMOGRAPHY:

THEORETICAL FUNDAMENTALS AND APPLICATIONS IN ONCOLOGY

S.S.Zamyatin, O.V.Shcherbina*

Kyiv Municipal Oncological Hospital, 69 Verkhovynna St., Kyiv 252115, Ukraine

*P.L.Shupyk Kyiv Medical Academy of Postgraduate Studies

The fundamentals and principles of operating og a highly effcient technique for oncological diseases diagnostics – one-photon emission computer tomography – are described. Its characteristics are compared to those of other methods of early diagnostics and the examples of practical applications are presented.

ON THE POSSIBILITY OF OBSERVATION OF INDUCED

GAMMA-EMISSION ON 178m2Hf(16+) ISOMER

T.M. Zayats

Department of Nuclear Physics, Uzhgorod State University,

46 Pidhirna St., Uzhgorod 294000, Ukraine

e-mail: ztm@gaser.uzhgorod.ua

The mechanism of 180m Ta( g , g ‘) 180 Ta and 178m2 Hf(16 + )( g , g ‘) 178 Hf reactions in the energy range below 3 MeV is discussed. The induced gamma-emission is considered as a specific form of inelastic scattering of g -quanta from the spontaneous decay of 178m2 Hf(16 + ) isomer. An experiment scheme is proposed to testify the conclusions made.

ASYMPTOTIC BEHAVIOUR OFTHE NEAR-TO-MAGIC NUCLEI TERMS AT HIGH R
IN THE ADIABATIC HYPERSPHERICAL APPROACH

M.M. Kapustei

Department of Nuclear Physics, Uzhgorod State University,

46 Pidhirna St., Uzhgorod 294000, Ukraine

The asymptotic behaviour at R ® ¥ of terms as solutions of the equation on a is considered. Parameters of potentials of interaction of nucleons with the core and one with another, asymptotic values of terms and energies of 0 + states of 18 O and 42 Ca nuclei are found. The obtained results are compared with the experimental data.

LASERS ON SELFTERMINATING TRANSITIONS:

CURRENT STATE AND RESEARCH DIRECTIONS

V.A.Kelman

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

A chart of excitation of lasing on selfterminating transitions, the criteria for the effective active media for such lasers, a short historical essay are presentes. New media for lasers on selfterminating transitions (Ti, Ni, V) and methods to obtain the vapours of these elements in discharge are proposed. The examples of practical applications of these lasers are given.

SOME METHODS OF INCREASE OF SENSITIVITY AND SELECTIVITY

AT THE DETERMINATION OF W(VI) AND Re(VII)

WITH ALKALINE CYANINE DYES

Zs.O.Kormos

Chemical Faculty, Uzhgorod State University,

46 Pidhirna St., Uzhgorod 294000, Ukraine

The ion-pair extraction of rhenium with cyanine dyes has been studied. It has been shown that the ion-pair extraction increases on addition of large amounts of salting-out agents. Interaction and precipitation of tungsten with cyanine dyes in aqueous solution were studied spectrophotometrically and the optimal conditions were found. The composition and spectrophotometric characteristics of the ion pairs formed were estimated.

EXPERIMENTAL INVESTIGATION OF NEAR-THRESHOLD EXCITATION
OF AUTOIONIZING STATES IN LITHIUM ATOMS

IN ELECTRON-ATOM COLLISIONS

V.N. Krasilinec

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

Using the electron spectroscopy method and crossed-beam technique the ejected-electron excitation functions of the (1s2s 2 ) 2 S, (1s2s2p) 4 P 1/2,3/2 , 1s(2s2p 3 P) 2 P and 1s(2s2p 1 P) 2 P autoionizing states in lithium atoms have been obtained in the impact energy region from the excitation thresholds to 600 eV, at the 54.7 0 observation angle and at the energy resolution of 0.4 eV. The resonance structure revealed in all excitation functions has been related to the electron decay of negative-ion levels and to the radiative cascades from the upper levels. The results obtained show the dominant role of resonance processes in the near-threshold excitation of autoionizing states in lithium atoms.

ANION SUBLATTICE MODIFICATION

OF YBa 2 Cu 3 O 7- d HTSC-CERAMICS

R.T.Mariychuk

Institute of Physics and Chemistry of Solids

Uzhgorod State University, 46 Pidhirna St., Uzhgorod 294000, Ukraine

The analysis of earlier studies on attempts of YBa 2 Cu 3 O 7- d compound anionic sublattice modification is presented. YBa 2 Cu 3 O 7- d Fluoration is concluded to be promising in order to increase the critical parameters. The results of studying the properties of fluorine- and chlorine-doped YBa 2 Cu 3 O 7- d compound prepared by solid state reaction are presented. The properties of YBa 2 Cu 3 O 7- d are investigated by methods of X-ray diffraction, microstructure analysis and temperature dependences of electric conductivity.

OBTAINING AND PROPERTIES OF LEAD ANTIMONATES

P.M.Milyan

Chemical Faculty, Uzhgorod State University,

46 Pidhirna St., Uzhgorod 294000, Ukraine

PbSb 2 O 4 , PbSb 2 O 5 and Pb 2 Sb 2 O 7 ternary compounds were produced by solid state reaction of PbO and Sb 2 O 3 , Sb 2 O 4 , Sb 2 O 5 stoichiometric mixture. For the latter the measurements of dielectric permeability and calculation of tangent of dielectric losses were performed.

THE ELECTRICAL CIRCULATION SYSTEM OF RF * -EMITTER

WORKING MEDIA

A.J. Minya

Institute of Physics and Chemistry of Solids

Uzhgorod State University,

46 Pidhirna St., Uzhgorod 294000, Ukraine

In the given work we present the results of investigation of the multielectrode corona discharge characteristics in the mixture He/Kr/SF 6 under the pressure of 100-300 kPa, which is used as working in pulse-periodic excimer lasers or lamps on l =249 nm KrF. We investigated the conditions of obtaining a stable negative corona discharge of the “needle-grid” type; which is uniformly distributed on the length of the excimer emitter active medium. It is shown that in the given media the corona discharge current is transferred mainly in the form of a stable component, through which the frequency of 20-250 kHz were observed. Optimization of the emitter operating was performed for the purpose of obtaining maximal average current and the speed of electrical wind in the external range of a multielectrode corona discharge. Hot zone of the given discharge was formed as separate point zones (distributed near the needle points) and was a source of selective emission on l =249 nm KrF and separate lines KrI (5s-5p,6p). The circulation system can be used in compact excimer lasers or lamps on f £ 100 Hz and the length of emitter active medium £ 10cm.

SPECTROSCOPIC STUDIES OF TRANSVERSE DISCHARGE PLASMA

ON AR/XE/HCL(CCl 4 ) MIXTURE

Yu.Yu. Neimet

Uzhgorod State University,

46 Pidhirna St., Uzhgorod 294000, Ukraine

The results of studies of pulse transverse discharge plasma emission in Ar and Xe mixtures with HCl and CCl 4 molecules, being used in electric discharge XeCl* lasers or lamps, are reported. The discharge was studied in 18 ´ 2.2 ´ 0.7 cm 3 volume at gas mixture pressures from 5 to 100 kPa. The emitter operating mode at l =308 nm XeCl* with CCl 4 molecule-based active medium is studied, a number of its parameters overcoming those of typical HCl molecule-based emitters. The transformation of such media with time is investigated.

INVESTIGATION OF DIELECTRONIC RECOMBINATION

AND EXCITATION OF RESONANCE LINES OF Zn + IONS

AT ELECTRON-ION COLLISIONS

A.N. Nemeth

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

The radiation, resulting from the dielectronic recombination (DR) at radiative transitions from the 3d 10 4p( 2 P 3/2,1/2 )nl autoionizing states (AIS) to the bound 3d 10 4snl states of Zn atom has been found below the excitation threshold of the resonance doublet of Zn + ions was detected using the ultraviolet spectroscopy and crossed-beam technique. The energy dependence of DR and excitation cross section was studied for the resonance doublet components in the energy range 4 - 120 eV. The distinct features due to the formation and decay of AIS of Zn atoms have been observed. The results are compared with those taken from the experimental and theoretical reference data.

MASS DISTRIBUTIONS OF ACTINIDE NUCLEI

PHOTOFISSION FRAGMENTS

O.O.Parlag

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

Mass spectra of 232 Th, 234 U, 235 U, 238 U, 237 Np, 239 Pu and 240 Pu actinide nuclei photofission fragments, obtained by semiconductor gamma-spectrometry, are analyzed in the framework of the mass-channel model of fission. The dependence of the inverse rigidity value of the mass-asymmetric deformation for the components of a0 and a1 mass-spectrometric modes on the nuclei fission ability parameter z 2 /A for the same temperature of the nucleus ~13 MeV is obtained. 

EXPERIMENTAL INVESTIGATION OF ISOMERIC FRAGMENT PAIRS EXCITATION
IN 232 TH NUCLEUS PHOTOFISSION REACTION

Yu.V. Pilipchenko

Uzhgorod State University,

46 Pidhirna St., Uzhgorod 294000, Ukraine

The isomeric ratios of Xe and Te fragment yields in 232 Th photofission reaction with the endpoints of bremsstrahlung 7.2, 7.5 and 8.2 MeV were measured. The isomeric ratio experimental values were corrected on the contribution of predecessor b -decay.

THE STUDIES OF THE ENERGY STRUCTURE OF SI–P(100) AT THE

SLOW ELECTRON INELASTIC SCATTERING BY 180 °
T.Yu. Popik

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

Using the hypocycloidal electron spectrometer the energy-loss and the constant-residual energy spectra of slow (0–10 eV) monoenergetic ( D E 1/2 ~14 meV) electrons scattering by -p Si (100) have been studied by means of a “Crystal” experimental set-up. It has been shown that the combination of such studies in one experiment possesses large advantages as compared with the known methods due to obtaining much more information on the possible electron transitions in solids from upper filled (valence) band to the higher-energy (empty) bands, intraband transitions and surface electronic states.

BLUE-GREEN LASER ON TITANIUM VAPOUR

A.S. Rybak

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

Preliminary results of a pilot study on obtaining lasing from titanium atom self-terminated transitions are reported. Titanium tetraiodide and cathode evaporation in a discharge with a hollow titanium cathode are intended to be used for obtaining titanium vapour.

FORMING OF ELECTROMAGNETIC FIELD CONCEPT

AT THE LESSONS OF PHYSICS AND GENERAL

ELECTRIC ENGINEERING

N.M.Syhydenko

Svalyava Technical College, Ministry of Education of Ukraine,

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

Based on the long-term teaching experience, the peculiarities of the students' mastering program topics concerning electromagnetic field concept, being a rather complicated one, are considered. The problem consists in the fact this concept being one of the first in the physics lectural course when the students have not yet formed the meaning of abstract concept as a form of didactic perception. The teaching charts for the best acquiring knowledge of electrodynamics are given, the fundamental character of such physical concepts as electric charge, electromagnetic interaction and electromagnetic field is shown.

DESCRIPTION OF ATOMIC ELECTRON

IN CLASSICAL ELECTRODYNAMICS

V.M. Simulik

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

Unitary relationship and one-to-one correspondence between the solutions of stationary Dirac (with nonzero mass and nonzero interaction with external field) and Maxwell equations (in specific medium and containing the gradient-type electric and magnetic currents and charges) is found. Atomic electron is described on this basis in the framework of classical microscopic electrodynamics. A new method of solution of the atomic and nuclear physics problems, using generalized Maxwell equations in medium, is suggested. The Bohr’s postulates are derived on the basis of Maxwell equations.

THE ROLE OF SIMPLE SHELL CONFIGURATIONS

IN THE REACTION OF g -QUANTA INELASTIC SCATTERING

AT THE EXCITATION OF ATOMIC NUCLEI METASTABLE STATES

I.V.Sokolyuk

Department of Nuclear Physics,

Uzhgorod State University,

46 Pidhirna str., Uzhgorod 294000, Ukraine

e-mail: siv@gaser.uzhgorod.ua

The results on the activation levels of 107,109 Ag, 113 In nuclei observed in ( g , g ') m reaction along with the data concerning one-nucleon transfer reaction, are analyzed. The shell configurations of transitions from the 107 Ag, 109 Ag, 113 In nuclei ground state to the activation levels, corresponding to one-nucleon transitions between the subshells within the upper unfilled 2p1f1g-shell, are determined. The mechanism of resonance scattering of low energy g -quanta on nuclei is discused.

SPECIFIC FEATURES OF Tl 6 SeI 4 SINGLE CRYSTALS ABSORPTION

IN THE FUDAMENTAL BAND RANGE

L.P.Trachuk

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

The absorption edge of Tl 6 SeI 4 has been studied within a wide temperature range (77-293 K) in the fundamental band region. It has been found that within the given temperature range the direct “allowed”, direct “forbidden” and indirect “allowed” optical transitions occur for Tl 6 SeI 4 . The energy gap for various-type optical transitions has been determined, the dependence E g =f(T) has been plotted, and the temperature coefficient of energy gap variation has been calculated.

PECULIARITIES OF SLOW ELECTRON ELASTIC SCATTERING

BY THE SI-P (100) SURFACE

V. M. Feyer

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universytetska St., Uzhgorod 294016, Ukraine

e-mail: iep@iep.uzhgorod.ua

Using the hypocycloidal electron spectrometer the elastic scattering (180 ° ) of slow (0–10 eV) monoenergetic ( D E 1/2 ~14 meV) electrons by polished and dull Si–p(100) surfaces has been studied by means of the technique proposed. The specific feature of the energy dependence of elastic backscattering coefficient is broadening of maximum for the dull surface as compared with the polished one. The singularities in the separate areas of curves within the (0.5–2.0) eV energy range in a form of violation of smooth decrease have been revealed. The elastic backscattering coefficients were found to be extremely sensitive to the surface roughness degree.

APPLICATION OF SUCCESSIVE ANALYSIS OF VARIANTS

ALGORITHM FOR CONSTRUCTION OF SCHEDULES COMPLYING

WITH THE DIRECTIVE TERMS OF THE WORK EXECUTION

T.B. Shpenik

Uzhgorod State University,

46 Pidhirna str., Uzhgorod 294000, Ukraine

A problem, where the set of N requirements fits into the system of M identical parallel devices, is considered. Each requirement i is entered on the queue to be operated at d i =0 moment of time and is served during t i >0 time units by any device without interruption. A directive period D i is given to each requirement i. The algorithm of search for the minimal amount of devices based on the method of successive analysis of variants, is proposed.

 

Ion Beam Surface Diagnostics

International Workshop, Uzhgorod, August 25-29, 1998

 

The proceedings of the Eighth International Workshop on Ion Beam Surface Diagnostics, are devoted to the ion beam methods of surface analysis, their applications and apparatus; fundamental investigations of ion-surface interactions (physical principles of analytical methods): mechanisms of sputtering, scattering, desorption, surface modification, ion and excited particle formation, effects of chemical environment etc.

 


Chemistry, Physics and Technology of Chalcogenides
 and Chalcohalogenides

9th scientific and engineering conference, October 7-10, 1998, Uzhgorod

The conference was organized by Uzhhorod State University, Department of Inorganic Chemistry, Institute of Solid-State Physics and Chemistry, Institute of Electron Physics, Ukr. Nat. Acad. Sci., Institute of General and Inorganic Chemistry, Ukr. Nat. Acad. Sci., Institute of Material Science, Ukr. Nat. Acad. Sci. etc.


 

Science, Technology, Progress
International regional workshop,

May 29-30, 1998, Uzhgorod

 

The workshop was organized by Transcarpathian Union of Sicentific and Engineering Societies, the Regional Council of Scientific and Engineering Society  of Device Producers and Metrologists, Scientific Department of Hungarian Academy of Sicences in Szabolcs-Szatmar-Bereg Province, The World Union of Hungarian Engineers and Architects, Uzhhorod Agency of Business Development, Uzhhorod State University, Institute of Electron Physics, Ukr. Nat. Acad. Sci.


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