CLOSED SUPERCONDUCTING COSMIC STRINGS IN THE CYLINDRICAL-SYMMETRIC FIELDS OF EINSTEIN-MAXWELL

A.V. Zhovtan, S.N. Roshchupkin

Full Text :   (360 kB, Rus.) 

Abstract
Dynamics of closed superconducting cosmic string is considered in the axisymmetric gravitational fields induced by either the axial current or by the azimuthal current or by the axially distributed electrical charges. It is shown that the dynamics of the closed superconducting string in all three cases can be described by effective particle-like Hamiltonian. The investigation of the effective potentials has been carried out and the numerical solutions of the classical motion equations of the closed superconducting string have been obtained. It is shown that the string dynamics has nontrivial character and depends substantially both upon background metric parameters as well as and string's parameters.

KEY WORDS: superconducting cosmic string, Einstein-Maxwell fields, effective potentials, numerical solutions.

SRTUCTURE OF TENSOR REPRESENTATION FOR THREE–NUCLEON BOUND–STATE WAVE FUNCTION

V.V. Kotlyar, A.O. Shcheglova

Full Text :   (1110 kB, Rus.) 

Abstract
Symmetry properties of tensor wave function (WF) for three-nucleon bound state are discussed. The nucleons are treated as identical particles. The tensor WF is expressed in terms of space, spin and isospin functions that belong to irreducible representations of the symmetrical group. Relations between the WFs in tensor and operator forms are analyzed. The scalar functions that determine the WF in the operator form are calculated for the Reid soft core potential.

KEY WORDS: tensor wave function, Gerjuoy-Schwinger operator representation, few-nucleon systems, nuclei ³Не and ³Н

VECTOR ANALYZING POWER FOR ⁹ВЕ(d,a)⁷LI REACTION AT THE LOW DEUTERON ENERGIES AND CONTRIBUTION OF THE DIRECT TWO-NUCLEON TRANSFER MECHANISM

V.D. Sarana, N.A. Shlyahov

Full Text :   (880 kB, Rus.) 

Abstract
The possibility of the description of the previously obtained experimental data for angular distributions of differential cross section and VAP and energy dependence VAP of the reactions ⁹Ве(d,a)⁷Li, induced by vector-polarized deuterons with energies from 1,4 to 3,0 MeV, in the framework of DWBA is considered. The satisfactory fitting of the zero range DWBA calculations to date for angular distributions of the cross section and VAP for reaction ⁹Ве(d,a₁)⁷Li (0,48 МэВ ½^-) is obtained. The particular angular distribution properties of the measured observables for transition to ground state of the ⁷Li_o.c. only with cut-off of the radial integrals, what may to point importance of the finite range interaction, is reproduced. However, calculation with FRDWBA to be unable reproduced second peak in the angular distribution of the cross section for this transition. The basic tendency of the energy dependencies of VAP for both transitions were described on average using parameterizations obtained by analysis of the angular distributions. At the same time the presence of sharp anomalies from mentioned tendency points to strong interference effects concerned with possible contribution of the states of the compound nucleus, although direct process is predominant both at forward and backward angle regions.

KEY WORDS: nuclear reaction, beryllium, two-nucleon pick-up, cross section, VAP, angular distribution, energy dependence, DWBA, zero and finite rang.

THE GENERALIZED EQUATION OF GRAVITATION IN TYPE MODELS  f (R_abgd )

A.T. Kotvitskiy, D.V. Kryuchkov

Full Text :   (200 kB, Rus.) 

Abstract
In the work equations of gravitational field for action with any dependency of Lagrange's density from different scalars of curvature are researched. The main purpose of the research is the creation of generalising equation for gravitational models of type. There is familiarization with the square-law and polynomial actions and the corresponding gravitational equations at first. Hereinafter most general action with any dependency of Lagrange's density from different scalars of the curvature is considered and the generalising equation of gravitational field is created. At the end of the work the gravitational equation for action with Lagrange's density in form of third degree of curvature is built as example of using of the created generalization.

KEY WORDS: action, square-law gravitation, Lagrangian, polinomial model, Einstein's tensor

MODELLING OF SPECTRA AND YIELD OF PROTONS OF FEEDBACK FROM HYDROGENOUS FILM AT THEIR IRRADIATION FAST NEUTRONS

S.K. Andruhovich, V.P. Bozhko, A.N. Vodin, S.N. Olejnik, S.A. Soldatov, E.A. Rudak, O.I. Jachnik

Full Text :   (250 kB, Rus.) 

Abstract
The mathematical model of fast neutron interaction with hydrogen nuclei containing in thin films is developed. The computer code "NP-Recoil" is created to calculate the recoil proton spectra and yields by the Monte-Carlo method. The algorithm is based on the (n,p)-reaction kinematics and recoil proton energy losses in the film without taking into account the multiple proton scattering. The calculations of recoil proton spectra and yields from the polyethylene films are carried out for the neutron energy 1 - 15 MeV at angles 0 - 90°. It is found that the received results are satisfactorily conformed to the calculations by the MCNPX code.

KEY WORDS: fast neutrons, recoil protons, proton spectra and yields, hydrogenous film, mathematical model.

ELECTROMAGNETIC PULSE GENERATION AT CYCLIC REVERSAL MAGNETIZATION OF WROUGHT FERROMAGNETIC ALLOYS

N.A. Azarenkov, A.I. Velikodniy, V.G. Kirichenko, Т.А. Коvalenko, M.G. Kompaniets, S.Yu. Kochetova

Full Text :   (730 kB, Rus.) 

Abstract
Research results of Co-Fe-Nb alloy system with huge Barkgauzen jumps of Vigand type are presented. Physical mechanisms of magnetic and mechanical properties formation of Co-Fe-Nb alloys are investigated. To produce a bistable magnetic wire used composite cylindrical materials based on magnetic semi-rigid Co-Fe-Nb alloys with the high contents of cobalt (> 70 %) used as a sheath and with an m-permalloy core. Magnetopulse elements based on these alloys were obtained. The parameters of the element were as follows: amplitude of reversal magnetization pulse was 10 V at pulse-repetition frequency of up to 20 kHz, and pulse duration of 10 mcs with resistance of the reading coil of 30 Ohm in the working temperature range of 80 - 600 K, and working pressure range of up to 300 MPa.

KEY WORDS: ferromagnetic, Barkgauzen jumps, cobalt alloys, magnetopulse elements

STRUCTURAL AND TEXTURAL ANALYSIS ROLLED SHEETS OF BERYLLIUM

I.I. Papirov, A.A. Nikolaenko , V.A. Shkuropatenko, G.S. Koshkarev

Full Text :   (2900 kB, Rus.) 

Abstract
Influence of rolling temperature, metal purity, total and unite strain level, temperatures and duration of annealing on dislocation structure, texture and mechanical properties of beryllium sheets is studied. It is established, that the optimum combination strength and plastic properties is reached in a material with generated low-dislocation subgrain structure. Realizations of such substructure promote high temperatures of deformation (above temperature of recrystallization) and purity of material. Optimum condition of rolling beryllium sheets are defined: temperature 850-900°С at unite strain level up to 30%.

KEY WORDS: beryllium, rolling of beryllium, beryllium sheet, structure, texture, mechanical properties.

MULTISCALE STRUCTURES FORMING ON THE GRAPHITE SURFACE

V.G. Kirichenko, E.S. Melnikova

Full Text :   (1200 kB, Rus.) 

Abstract
The results of experimental investigation of graphite surface by scanning tunneling microscopy are presented. The periodic modulation of surface electron density is founded. The character of this modulation is similar to the fine-scale modulation of electron density in crystal cell on graphite surface. There is various directions and scalability's overfall of height in carbon atoms' placement even in the terms of pure graphite surface. In case there are neighboring C atoms there is possibility to use this overfall's increase for explanation of the first stag of the process of carbon graphite sheet's roll.

KEY WORDS: graphite, surface, largescale structures, modulation, elementary cell, fluctuations.

SIMULATION OF RESPONSE FUNCTION OF CDZNTE DETECTORS FOR GAMMA-RADIATION DOSIMETRY

A.A. Zakharchenko, A.A. Veryovkin, V.E. Kutny, A.V. Rybka, M.A. Khazhmuradov

Full Text :   (300 kB, Rus.) 

Abstract
A procedure allowing to obtain a response function of CdZnTe planar detector used for gamma-ray dosimetry is developed based on the Monte-Carlo method. For reliable reconstruction of the detector response function the experimental spectra only from three sources: ²⁴¹Am, ¹⁵²Eu and ¹³⁷Cs will suffice. The proposed method was used for the calculation of the discrete sensitivity of CdZnTe dosimeter detector module.

KEY WORDS: response function, CdZnTe, detector, gamma-radiation, dosimetry, Monte-Carlo method, EGSnrc.

INTEGRATION OF COMPUTATION METHODS IN RADIATION STERILIZATION PROCESS

V.T. Lazurik, V.M. Lazurik, G. Popov, Yu. Rogov, Z. Zimek

Full Text :   (290 kB, Eng.) 

Abstract
Authors have developed the computer technology for simulation of practical tasks in radiation sterilization process in accordance with Method 1, Standard ISO 11137 and IAEA Code of Practice. The technology was realized on the base of the RT-Office modules for modeling by Monte Carlo method of an absorbed dose in an irradiated heterogeneous targets with electron beam (EB), X-ray and gamma-ray and specialized software ModeSAL. The software ModeSAL was used for simulation and comparative analysis of a sterility assurance level (SAL) and a sterilizing dose for bioburden to achieve a required SAL in an irradiated product. The mathematical approach of the technology is based on the detailed and precise consideration of a self- consistent physical and geometrical models of calculation an EB, X-ray and gamma-ray dose maps in an irradiated product, a SAL, a sterilizing dose and the spatial and time uncertainties for dose provided to an irradiated product. The analysis of interrelations between parameters of EB radiation facility and values of a SAL and a sterilizing dose are considered.

KEY WORDS: radiation sterilization, Standard ISO 11137, RT-Office, software ModeSAL, dose map

OPTIMIZATION OF THE IRRADIATION PARAMETERS WITH THE AIM OF Х-RAY TREATMENT OF MAXIMAL THICKNESS ARTICKS

V.T. Lazurik, V.G. Rudychev, D.V. Rudychev

Full Text :   (670 kB, Rus.) 

Abstract
Some particularities of dose distribution forming in radiation-technological lines (RTL) have been investigated, which correspond to X-rays from 5 MeV electrons, extensive converter and running objects. It is shown, in the low density irradiated objects the heterogeneity of absorbed dose field is determined by the next geometrical parameters: converter to object distance and length of irradiated area along the converter. It is found, that a maximum thickness of such irradiated objects Z_max is well-proportioned to the converter length under DUR<1.5 condition. It is shown, that in high density objects the converter extension does not lead to Z_max growth. The analysis of the converter modification with the aim of obtaining the maximal processed thickness showed the way of increase of X-ray mean energy.

KEY WORDS: radiation technology, X-ray, bremsstrahlung, extensive converter, electron

REDISTRIBUTION OF LABILE OXYGEN AND PHASE STRATIFICATION IN STRONGLY UNDERDOPED BY OXYGEN ReBa₂Cu₃O_7-d (Re=Y, Ho) SINGLE CRYSTALS

R.V. Vovk, I.L. Gulatis, M.A. Obolenskii, A.A. Zavgorodny, A.V. Samoilov

Full Text :   (360 kB, Ukr.) 

Abstract
In present work, effect of annealing at room temperatures on conductivity in the base plane of oxygen deficient ReBa₂Cu₃O_7-d (Re=Y, Ho) single crystals hard-tempered from the temperatures 600-650°C are investigated. It is shown that in the process of annealing takes place considerable to transformation of form of superconductivity transitions. It is explained the got results by the equipment modern with amenities of labile oxygen without the change of his concentration in a bulk. The results can be explained by the ordering of the labile oxygen without changing its concentration in the sample. The estimation of the cluster sizes is characterized by the differences in oxygen content. We perform a comparative analysis between the experimental data with the estimations, within the frame of the high temperature superconductivity cluster theory.

KEY WORDS: HTSC, annealing, labile oxygen, ReBa₂Cu₃O_7-d (Re=Y, Ho) single crystals, pseudo-gap state, superconducting clusters

TEMPERATURE DEPENDENSES OF PSEDOGAP IN ReBa₂Cu₃O_7-d (Re=Y, Ho) SINGLE CRYSTALS WITH DIFFERENT OXYGEN CONTENTS

R.V. Vovk, A.A. Zavgorodniy, M.A. Obolenskii, K.A. Kotvitskaya, A.V. Samoylov

Full Text :   (640 kB, Ukr.) 

Abstract
In present work the temperature dependence of the ab-plane conductivity of ReBa₂Cu₃O_7-d (Re=Y, Ho) single crystals with the system of the unidirectional twin boundaries was investigated. The excess conductivity Δσ(Т) for the ReBa₂Cu₃O_7-d (Re=Y, Ho) single crystals shows exponential dependence in the wide temperature range T_f < Т < T*. In addition ratio Δσ~(1-Т/Т*)exp(Δ*ab/T) can be interpreted in the mean field theory, where Т* represents as mean field temperature of superconducting transition and temperature dependence of the pseudogap can be described satisfastionaraly in term of crossover BSC-BEK theory. Decrease of oxygen show the wider temperature range of PA realization but linear part of ρ(Т) in ab - plane becomes narrower.

KEY WORDS: excess conductivity, doping, YВaCuO single crystals, high temperature superconductivity, crossover, pseudogap state.

WELDING TITANIUM AND STAINLESS STEEL CRYOGENIC SECTIONS OF THE ELECTRON COLLIDER ILC

V.Е. Kovtun, N.I. Naval’nev

Full Text :   (190 kB, Rus.) 

Abstract
We suggest to use the joint of the two heterogeneous materials - titanium and austenitic stainless steel (Ti - SS) in the cryogenic (helium guide in accelerator's technique) structures of the electron collider ILC. The technological possibilities of the cryomodule's two pipe sections connection by the methods of electron-beam welding and diffusion vacuum welding, and also instrumental control of the welding process in the existed production conditions has been studied by us in the R&D framework (JINR, Dubna - KhNU, Kharkov). Such a methods has not been studied good enough for the "titanium-steel" materials, especially the possibilities for the usage of such a joints at low temperatures. Nevertheless the "titanium-titanium" and the "titanium-other materials" joints are widely used in the aerospace technique. The standard equipment and the vacuum technological stands of the Kharkov machine buidling factory "FED" has been used.

KEY WORDS: linear electron collider, cryomodule, titanium, stainless steel, electron-beam welding, diffusion welding.