East European Journal of Physics

4-22

Authors: V.V. Yanovsky, A.V. Tur, M.I. Kopp

The survey covers a main achievements in the field of dynamo theory. Applications of the model of turbulent convective dynamo to the problem of generation of a large-scale vortexes and magnetic structures in the solar photosphere are discussed. Investigated are the new models of the vortex dynamo in a rotating fluid with small-scale external force. The main results in these models are obtained by the method of multiscale asymptotic expansions. The results of numerical analysis of nonlinear equations of a magnetovortex dynamo in a stationary mode are provided. Solutions are found in the form of spiral kinks, periodic nonlinear waves and solitons, which are also considered in the survey.

35-40

Authors: Y.V. Rudychev

A combined technique using both Monte-Carlo and quasi-analytic method has been developed for calculation of irradiation from complex objects containing radioactive waste. Monte Carlo method is used to calculate spectral, angular and spatial distributions of γ-quanta close to one of the surfaces of the concrete cask loaded with containers filled with radioactive waste (RW). Radiation characteristics at the prescribed distance are determined by integrating the point sources with calculated distributions over this surface. Summation of photons of external radiation from individual RW isotopes allows finding the photon flux for any storage time. Application of the technique allows to calculate asymmetric loading of casks with containers filled with RW of different activity and to optimize the arrangement of the casks in the RW storage area. This allows reducing the effect of radiation-absorbed dose on the service personnel and on the areas surrounding RW storage.

49-60

Authors: V.A. Shkuropatenko

The results of experimental research for obtaining of phosphate matrix materials: fluorapatite Ca10(PO4)6F2, sodium zirconium phosphate NaZr2(PO4)3 and potassium magnesium phosphate KMgPO4·6H2O were presented. The evolution of phase composition in their synthesis was investigated. The optimal parameters for obtaining monophasic phosphate matrix materials were found. Possibility of obtaining powders of calcium Ca10(PO4)6F2 and strontium-containing Ca9Sr(PO4)6F2 fluorapatites by both solid phase reaction method with subsequent heat treatment and chemical co-precipitation method from solutions of the initial components was investigated. Nanosized zirconium orthophosphate powders NaZr2(PO4)3 were synthesized by the sol-gel method. Hydrated phosphatic matrices KMgPO4·6H2O by a chemical reaction between MgO and KH2PO4 in water at a room temperature were obtained. The requirements for high-level waste matrix were presented. The suitability of the use of synthetic phosphate materials as a matrix for the immobilization of high level nuclear wastes was determined.

67-71

Authors: V.G. Kirichenko. R.S. Nestarenko, T.A. Kovalenko

On the basis of experimental data the analysis of phase changes in intermetallic phases in alloys on the basis of zirconium (Zr – 1,03 ат.% Fe; Zr – 0,51 ат.% Fe; Zr – 0,51 ат.% Fe – М (М = Nb, Sn,Ta) is carried out. We used experimental techniques: Mössbauer spectroscopy on 57Fe nuclei in backscattering geometry with the registration of the internal conversion electrons, X-ray analysis, X-ray diffraction and electron microscopy. As a result is found the interrelation between process of growth of inclusions of intermetallic phases and segregation of these phases. The growth of particles derived by phase transformation, recrystallization and interrelated. In our case the detected phase separation of two types, so iron is transferred from one phase to another at short diffusion paths. The kinetics growth of inclusions is not controlled by bulk diffusion, and a lower value of the activation energy of migration of iron atoms can be bound with existence of enhanced diffusion paths and interphase borders.