Препринты / Preprints

The attempt of relativistic consideration of unclosed model of the flat Universe is undertaken. The relativistic version of the Hubble’s law is obtained. It is shown, that for z > 0.2 one must use the relativistic approach. It is shown, that if the relativistic velocity is increasing, the behavior of thermal and synchrotron emitters appreciably differ: the intensity of .thermal emitters very promptly and without restriction is decreasing, while synchrotron emitters intensity, slightly weaken and then asymptotically are tending to the limit which further does not depend on distance. Therefore, one can seem, that the most remote part of the Universe consist not of thermal, but of synchrotron emitters. The simultaneous measuring of both shifts: and of wavelength, and of frequency for the same spectral lines, is offered, in particular, in order to be sure, that the dispersion equation for light justly in all Universe.

---------------------------

It is shown theoretically and experimentally that when a Gaussian beam illuminates a bicomponent diffraction system with small Fresnel numbers, consisting of two plane screens with circular apertures on given optical axes, in a near zone of the second screen the effect of diffractive multifocal focusing of radiation is observed. In this case, the diffraction picture from the second screen in the focal planes represents the circular nonlocal bands of the Fresnel zones with a bright narrow peak at the center, whose intensity can exceed by six times the value of the incident wave intensity. The proposed diffractive method allows the focusing of the wide-aperture beams without using classical refraction elements such as lenses and prisms, and it is applicable to both low-intensive and high-power radiation. The energy efficiency of diffractive focusing of Gaussian beams is as high as 70%. Such a method can improve the energy efficiency of the fiber coupling of diode lasers and can increase the intensity of radiation on a fiber exit up to a factor often. Keywords: Gaussian beams, wave diffraction, diffractive focussing of radiation, bicomponent diffracting system. Lebedev Physics Institute, Russian Academy of Sciences (Samara Branch); renat@fian.samara.ru; phone 007 8462 340-536; fax 007 8462 355-600

---------------------------

One of the most important problems of the modern cosmology is the formation of large scale structure (LSS)’m the Uni?verse. A last decade progress in obser?vation cosmology allows the comparison of model predictions with the main ob?servable characteristics of LSS as well as cosmic microwave background amsotropy (CMBA). The constraints for cosmolog-ical parameters arisen from galaxy clus?ter abundance and evolution are pre?sented. We argue that most cosmologi-cal models which are in agreement with observational data at z = 0 do not fit the evolution test and thus are not consis?tent. The models with a non-zero cos-mological constant are in better situa?tion regarding the evolution test.

---------------------------

Content Method of regular measurements of cosmic rays in the atmosphere. Galactic cosmic rays. Solar cosmic rays, precipitation, and radioactivity in the atmosphere. Cosmic ray fluxes and atmospheric processes. Conclusion.

---------------------------

In the framework of Abelian theory we consider the pure — neu?tron matter of high density in the flat Minkowski space — time. The Schwinger method of external sources based on the technique of func?tional derivatives is first used for calculating the formula of correla?tion energy of the high density matter. The obtained result for the correlation energy just does not contain the scalar — vector (mixed) polarization operator. This fact is the consequence of the covariance of massive neutral vector field equation and of the current conserva?tion. In the high density limit, the role of many — particle effects and vacuum polarization increases and becomes essential. The dependence of correlation energy on density is nonlinear. Such a behaviour of correlation energy leads to the instability of sys?tem and, as consequence, the phase transition in more dense state is possible. It is important to note, that the correlation energy enters in the formula of the ground state energy with negative sign, rather than positive one, because of repulsive character of nuclear forces, under the high density of neutrons.

---------------------------

It has been stated many times that the formation of radiation infringements in PbW04 is to big extent stipulated by non-stoichiometry defects of the crystals, arising in the process of their growth and annealing. To refine the idea of characteristics of the non-stoichiometry defects and their effect on the radiation hardness of PbWC>4 the current study is aimed at the melt composition infringements during its evaporation and at optical transmission of crystals obtained in these conditions after their irradiation (l37Cs source). In the optical transmission measurements along with traditional techniques a method «in situ» was used, which provided the measurements in fixed points of the spectrum (380; 470 and 535 nm) directly in the process of the irradiation. X-ray phase and fluorescence analysis of condensation products of vapours over PbWC>4 melt has found PbWC>4 phase in their content as well as compounds rich in lead PbO, Pb2WC>5 with overall ratio Pb/W (3.2). Correspondingly the lack of lead and variations in the content of oxygen are pointed out as the major growth defects of non-stoichiometry of PbW04 crystals. The oxygen variations are determined by the partial oxygen pressure in the atmosphere of growth or annealing of the crystals. The obtained results were compared with known conceptions of PbWC4 crystal colour centres. The possibilities of the formation of these centres accounting for the discovered loss of lead and oxygen exchange between the external medium and the crystal were considered.

---------------------------

Numerical codes developed for modeling RF discharge waveguide and slab CO2 lasers and waveguide lasers on IR atomic Xe transitions were adapted to simulate RF discharge in gas mixtures containing CO molecules. The experiments on studying the properties of RF discharge in gas mixtures containing CO molecules were carried out to compare experimentally obtained and theoretically calculated data. Modified room temperature RF «slab» laser setup with diffusion cooling of discharge region was used in the experiments. Binary mixtures He:CO with respective concentration of CO from 0 up to 20% at total pressure of 30 and 60 Ton-were studied. The dependencies of inter electrode root mean square (RMS) voltage and voltage-to-current phase shift on specific input power loaded into RF discharge were obtained. The results of the experiments were compared with numerical calculations.

---------------------------