21 research outputs found
Application of secondary ion mass spectrometer for measuring the diffusion profiles in alkali-halide crystals
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
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
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
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
Investigation of scaling properties of pseudorapidity distributions in π\u3csup\u3e-\u3c/sup\u3eA collisions
The scaling properties of pseudorapidity distributions are investigated in π- collisions with nuclei of photoemulsion. The densities of theses distributions are found to obey a new scaling law in the central region