PROBLEMS OF RADIATION STABILITY STRUCTURAL MATERIALS IN NUCLEAR POWER

V.N. Voyevodin, I.M. Neklyudov

Full Text :  (2400 kB, Rus.)

Abstract
Mechanisms of radiation damage of structural materials for nuclear power and problems of radiation-resistant materials development for operating and prospective reactors of new generations are examined. Analysis of state and of prospective of this problem solution shows that despite the considerable efforts of scientists round the world economically necessary levels of operation of existing nuclear reactors are not attained. This is defined to a considerable extent by insufficient radiation resistance of the main structural materials of operating nuclear plants - of different classes stainless steels and of zirconium alloys. The key problem for material science security of modern nuclear power and of future power engineering is the study of micro structure evolution and of its influence on degradation of initial physical-mechanical characteristics of materials.

KEY WORDS: nuclear energy, structural materials, radiation-strength materials, radiation defects, thermal reactors, fast nuclear reactors, effect of transmutation, spallation systems.

WAVELET ANALYSIS OF SMALL ENERGY-RELEASED EVENTS IN IONIZATION DETECTORS

S.S.Ratkevich

Full Text :  (1100 kB, Rus.)

Abstract
A method based on wavelet techniques has been developed and applied to identification of the rare events initiated by a weak interaction in low-background ionization detectors. The method is presented and described in some detail to show how it efficiently rejects events coming from noise and microphonism through a mathematical inspection of their recorded pulse shape. Advantages of two-parameter analyzing function of the one-dimensional wavelet transformation localized both in time, and on the frequency well adapted to study of structure of the nonuniform processes, as against transformation of Fourier are shown. Algorithms of fast discrete wavelet transformation of discrete signals are described on the basis of the multiresolution analysis. Possibilities of transformation are shown by the example of the analysis of model signals with well-known properties and the data of large low-background proportional counter filled with an enriched in 78Kr designed to search for 2K-capture of ⁷⁸Kr.

KEY WORDS: low-background detectors, wavelets, wavelet transformation, multiresolution wavelet analysis, nonparametric regression, noise rejection.

CONTROL OF ELECTRON AND ION ENTRAPPING/DETRAPPING IN HELICAL MAGNETIC FIELD WITH USE OF AC FIELD EFFECT

A.A. Shishkin, A.Yu. Antufyev, S. Morimoto, B. Weyssow

Full Text :  (900 kB, Eng.)

Abstract
Here it is shown that AC field can be used for the effect on the electron entrapping/ de-trapping process to improve the penetration of injected particles in the core of the confinement volume of the heliotron type device. Slowly changing in time a helical magnetic field transform the resonant passing ion (an ion that forms the drift island) into the helically trapped particle and causes the escape of the helically trapped ion from the confinement volume. Slowly varied in time AC field, which effects the entrapping / de-trapping process of the particle, can be produced with the helical conductor current varied in time.

KEY WORDS: helical magnetic field, particle transition processes, magnetic field perturbation, AC field.

PRODUCTION AND MEDICAL APPLICATION OF SHORT-LIVED AND ULTRA-SHORT-LIVED RADIOISOTOPES

A.A. Veryovkin, N.G. Stervoedov, G.P. Kovtun

Full Text :  (510 kB, Rus.)

Abstract
In this paper production methods and medical application of short-lived and ultra-short-lived radioisotopes are reviewed, radioisotope classification is given. Perspectives of photonuclear methods for isotope preparation on charged particle accelerators are noted. Specifications on target design and isotopic purity of target material are given. Data on isotopes (initial isotope, radioisotope impurity, mode of production, a half-life period, decay energy, radiopharmaceutical, field of use) commonly used in medicine, are listed. The main methods of radionuclide diagnostics are reviewed.

KEY WORDS: isotopes, production methods, nuclear medicine, radionuclide diagnostics.

ASYMPTOTIC PROPERTIES OF CURRENTS FOR HIGH-SPIN BOSON INTERACTION WITH TWO SPINLESS PARTICLES IN CONSISTENT MODEL

E.V. Rybachuk

Full Text :  (400 kB, Rus.)

Abstract
The scalar function in the current for the interaction of high-spin boson (HSB) with two spinless particles is derived in a consistent model. This scalar function provides the convergence of the double infinite integrals of the module for these currents times the HSB momentum with respect to p₀ and p₃ (where HSB momentum p=(p₀,0,0,p₃)).The function is found for any HSB spin J (J ³ 1) at one exception. This exception is related to some spinless particle moments. In last case the integrals diverge logarithmically. This divergence must be compared with the quadratic divergence of similar integral for the current in the superrenormalizable λφ³- theory. Using the found scalar function the asymptotic behaviour of the HSB interaction currents is derived. These currents for any spin J must decrease at least as |p_ν|^-4J-16 when |p_ν| → ∞. In such a way, these currents must decrease with J. Therefore in our approach the amplitudes for HSB interactions must have better asymptotic behaviour (better convergence) than the amplitudes for the spinless particle interactions in λφ³ - theory.

KEY WORDS: higher spin, boson, integral, convergence, interaction, current, consistency.

NEUTRON-PHYSICAL CHARACTERISTICS OF THE URANIUM-LEAD ASSEMBLY EXPOSED TO RELATIVISTIC DEUTERONS

V.А Voronko, V.V. Sotnikov, V.V Sidorenko, I.V. Zhuk, A.S. Potapenko, M.I. Krivopustov, S.R. Hashemi-Nezhad, P.S. Kizim

Full Text :  (460 kB, Rus.)

Abstract
Results are reported from the studies on the processes of neutron generation in the uranium-lead assembly with four sections of uranium blanket exposed to 2.52 GeV relativistic deuterons. The experiment described in this communication is a part of the scientific program „Investigations of physical aspects of the electronuclear method of power production and transmutation of atomic-industry radioactive waste using relativistic beams from the JINR (Dubna) Synchrophasotron/Nuclotron" included in the project „Energy plus Transmutation". The combined track-γ-spectrometric technique that provides information from one and the same sample was used to measure radial and axial distributions of fission rates, the reactions of radiative capture of ²³⁸U, and also the spectral index in the volumes of the target and blanket of the U/Pb assembly. Besides, the mentioned technique makes it possible to determine the production of ²³⁹Pu in the blanket of the U/Pb assembly. Comparison was made between the experimental data and the calculations performed with the use of the computer code MCNPX 2.5 e. Good agreement between the measurements and the calculations of spectral indices in the U/Pb assembly blanket testifies that the calculation model provides a correct description of the particle transport in the blanket substance.

KEY WORDS: electronuclear method, relativistic deuterons, neutron generation, uranium-lead assembly.

CALCULATION OF THE LIMITING DISTRIBUTION COEFFICIENTS OF ADMIXTURES IN ZIRCONIUM AND HAFNIUM

V.M. Azhazha, G.P. Kovtun, A.P. Shcherban’, O.A. Datzenko, D.A. Solopikhin

Full Text :  (300 kB, Rus.)

Abstract
In the present work the results of accounts the limiting distribution coefficients к_{0 limB} of separate impurities in zirconium and hafnium are presented. The calculations are carried out using the method mathematical analysis of liquidus and solidus curves of diagram states and graphical method of extrapolation these curves at zero concentration. It is shown coincidence of values к_{0 limB} determined by these settlement methods. The received data on values the limiting distribution coefficients of researched impurities in Zr and Hf are expanded a circle of the systems which represent interest for estimation the efficiency of purification these metals by crystallization methods. It has been determined the temperature and concentration parameters achievement of limiting values к_{0 limB} considered impurities in these metals.

KEY WORDS: zirconium, hafnium, distribution coefficients, directional crystallization, diagram states, admixtures, solvency, purification.

ION-PHOTON EMISSION OF ORGANIC SYSTEMS

V.V. Bobkov, S.P. Gokov, V.V. Gritsyna, D.E. Narushevich, А.L. Ulybkin, D.I. Shevtshenko

Full Text :  (250 kB, Rus.)

Abstract
In this work the investigation of emission spectra observed at Ar⁺ ions bombardment of organic systems inclusive an organic dye eosin (EO) were done to ascertain main characteristics of photon emission: spectral composition and quantum yields of emissions, and energy distribution of sputtered excited particles .The experiments were conducted in wavelength range: 250,0¸800,0nm. Basing on the data of quantum yields of radiation emitted by excited particles, some evaluations of a number of these particles sputtered by one incident ion were done. The analysis of spatial distribution of radiation above the target surface allowed estimating effective values of kinetic energies of sputtered excited particles. On the base of obtained data some suppositions about processes going in analyzed systems were done.

KEY WORDS: ion-photon emission, organic dye, spatial distribution of radiation, yields of radiation.

NUCLEAR PHYSICAL DIAGNOSTICS OF PROTONS IN THE COLLECTIVE ACCELERATOR OF IONS

N.P. Dikiy, D.V. Medvedev, I.N. Onishchenko, S.S. Pushkarev

Full Text :  (250 kB, Rus.)

Abstract
The procedure of the measurement of the accelerated beam parameters in the collective ion accelerator with the use of heavy current relativistic electron beams against the large background of electromagnetic interferences is developed. The accelerated hydrogen ions were registered with the aid of the nuclear reaction ¹¹В(р,α₁)⁸Ве by means of the detection of alpha particles. The intensification of the etching of the alpha particles tracks and an improvement of the "signal/background" relation was provide at the expense to the additives of methanol, hypochlorite and UV radiation. The use of reactions ¹⁴N(p,γ)¹⁵O, ¹⁹F(p,αγ)¹⁶O, ⁹Вe(р,α)⁶Li for studying the energy distribution of the accelerated protons is analyzed.

KEY WORDS: collective accelerator, ion beam, nuclear reactions, track detector.

AIMED FUNCTION OF MANUFACTURING SYSTEM WITH MASS PRODUCT OUTPUT

V.P. Demutsky, О.М. Pignasty, V.D. Khodusov, М.N. Аzаrеnкоvа

Full Text :  (370 kB, Rus.)

Abstract
The functioning industrial system with mass output is submitted in the microscopic description. Microscopic velues define trajectories of base products in considered technological space. Production technology of a base product sets the central technological trajectory. Work of technological equipment is submitted by numerical characteristics of stochastic process. The aimed funtional is introduced and aimed function of production system is constructed. The equation of the central technological trajectory is determined. Euler's equations for the central base product of industrial system are written.

KEY WORDS: synergetic, base product, the microscopic description, aimed function, Lagrange's function, Euler's equations.