21 research outputs found

    Application of secondary ion mass spectrometer for measuring the diffusion profiles in alkali-halide crystals

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    Depth profiles of magnesium, fluorine and oxygen impurities was examined in the surface layers of alkali-halide KBr crystals using method of secondary ion mass spectrometry. Samples of potassium bromide, coated with a surface film of magnesium fluoride were subjected to isothermal diffusion annealing in air at various times. It is shown that the diffusion of O ions occurs from the ambient atmosphere besides the diffusion of Mg and F ions during annealing of KBr crystals. Accurate estimation of the diffusion coefficients of cationic impurity Mg requires taking into account the possible interaction of this impurity and oxygen

    Wavelet analysis of angular distributions of secondary particles in high energy nucleus-nucleus interactions. Irregularity of particle pseudorapidity distributions

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    Experimental data on sulphur and oxygen nuclei interactions with photoemulsion nuclei at the energies of 200 and 60 GeV/nucleon are analyzed with the help of a continuous wavelet transform. Irregularities in pseudorapidity distributions of narrow groups of the secondary shower particles in the mentioned interactions are observed at application of the second order derivative of Gaussian as a wavelet. The irregularities can be interpreted as an existence of the preference emission angles of groups of particles. Such an effect is expected at emission of Cherenkov gluons in nucleus-nucleus collisions. Some of the positions of the observed peculiarities on the pseudorapidity axis coincide with those found by I.M.Dremin et al. (I.M.Dremin et al. Phys. Lett., 2001, v. B499, p. 97).)Comment: 11 pages, 7 figure

    Thermodynamic models of radiation-induced processes in solids

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    A thermodynamic model is proposed to qualitatively describe the radiation-induced processes in solids: temperature dependence of the X-ray radio luminescence output, dependence of these processes on the excitation density, energy accumulating in a solid under exposure to ionizing radiation and its temperature dependence. The proposed model and the formula derived can be used to develop radiation-resistant and radiation-sensitive materials

    Generation of intermediately-long sea waves by weakly sheared winds

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    The present study concerns the numerical modeling of sea-wave instability under the effect of logarithmic-wind profile in hurricane conditions. The central point of the study is the calculation of the wave growth rate, which is proportional to the fractional input energy from the weakly-sheared (logarithmic) wind to the wave exponentially varying with time. It is shown for hurricane conditions that the Miles-type stability model based on the Charnock's formula with the standard constant coefficient underestimates the growth rate ~5 to 50 times as compared with the model employing the roughness adopted from experimental data for hurricane winds. The drag reduction with wind speed at hurricane conditions coupled with the similar behavior of the dimensionless gravity acceleration, leads to the minimum in the maximal growth rate and the maximum in the most unstable wavelength.Comment: This paper has been withdrawn by the author due to misprinting error
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