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170 results on '"Barysheva, M."'

7. Study of the X-ray Optical and Mechanical Characteristics of C/Si and B4C/Si Multilayer Mirrors.

Author

Smertin, R. M., Barysheva, M. M., Garakhin, S. A., Zorina, M. V., Zuev, S. Yu., Polkovnikov, V. N., Chkhalo, N. I., and Radishchev, D. B.

Abstract

The X-ray optical and mechanical properties of dielectric multilayer mirrors based on pairs of C/Si and B4C/Si materials are synthesized and studied. The mirrors are optimized for a wavelength of 13.5 nm. Parameters of the deposition process that simultaneously ensure the fulfillment of three conditions are found: relatively high reflection coefficients at the operating wavelength, near-zero mechanical stresses in the film, and the absence of electrical conductivity. At zero internal stresses, the reflection coefficient of C/Si multilayer mirrors deposited onto superpolished silicon substrates at an operating wavelength of 13.5 nm is R = 11% and the spectral bandwidth is Δλ = 0.33 nm. The B4C/Si mirror provides the following characteristics: R = 8.2%, spectral bandwidth of Δλ = 0.3 nm. However, blistering is found in B4C/Si multilayer mirrors, i.e., the appearance of bubbles on the film due to the accumulation of hydrogen inside, which excludes their use for deposition onto commercially available microelectromechanical systems of micromirrors. The deposition of a C/Si coating made it possible for the first time to obtain an efficient microelectromechanical system that reflects X-rays at an operating wavelength of 13.5 nm. The reflection coefficient is about R ~ 3%. The low value of the reflection coefficient is due to the high, about 2 nm, microroughness of the surface of the microelectromechanical-system micromirrors. The study performed indicates the fundamental possibility of creating a matrix X-ray optical element for modulating the spatial and temporal characteristics of X-ray beams. [ABSTRACT FROM AUTHOR]

Published
2023
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8. International and national practice for estimating cash expenditures of road replacement, repair and maintenance

Author

Gogolev V and Barysheva M

Subjects
Social Sciences
Abstract

The paper considers the importance of the uninterrupted functioning of the transport network, which is the most important condition for eliminating the transport inaccessibility of Arctic territories of the regions, thus excluding transport discrimination of the population living in the Arctic zone of the Russian Federation. Besides, the paper provides a brief overview of international road repair and maintenance experience on the example of Norway, analysis of the standard for repair and maintenance of roads in the Russian Federation, proposals on the method of calculating the cash expenditures of replacement, repair and maintenance of roads in the Russian Federation. The Decree of the Government of the Russian Federation No. 658 dated May 30, 2017 approved the standards of financial expenditures and the rules for calculating the size of federal budget allocations for replacement, repair and maintenance of federal roads. However, at the moment, not all regions have updated the regulatory framework on the norms of financial expenditures and the rules for calculating budget allocations for replacement, repair and maintenance of regional and inter-municipal roads. The existing methodology for calculating the cost of repair and maintenance of roads in the Arctic territory of Russia does not fully provide the need to bring the existing roads into normal transport and operational condition for their safe operation. The analysis shows that there is no systematic work to ensure sustainable financing of the road economy in the republic and the road industry is financed at a level much lower than the actual needs.

Published
2021
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9. Broadband normal-incidence mirrors for a range of 111–138 Å based on an a-periodic Mo/Be multilayer structure

Author

M. Barysheva, M., A. Garakhin, S., O. Kolesnikov, A., Pirozhkov, Alexander, N. Polkovnikov, V., N. Ragozin, E., N. Shatokhin, A., M. Smertin, R., V. Svechnikov, M., and A. Vishnyakov, E.

Abstract

Broadband Mo/Be multilayer structures were designed for maximum uniform normal-incidence reflectivity in a broad range of 111–138 Å, which lies near and beyond the L2,3 absorption edge of Si. A comparison was made of the capabilities of two classes of aperiodic structures and of so-called “stack” structures, which are composed of several periodic structures with different periods stacked one over the other. Six-stack Mo/Be 80-layer structures were synthesized on concave (R = 1 m) superpolished fused silica substrates. Their absolute reflectivity was measured at 13% – 14% in the 111–138 Å optimization range using a laboratory reflectometer with a laser-plasma radiation source. The normal-incidence reflection spectra of the mirrors were recorded in the configuration of a transmission-grating spectrograph using the slowly varying quasicontinuum of a laser-driven tungsten plasma. Comparing the reflectivity data with the reflection spectra recorded with a CCD permitted estimating a decrease in the detector responsivity beyond the Si L-edge. The broadband normal-incidence multilayer mirrors facilitate the development of a high-resolution imaging spectrograph covering a usable range about the Si L-edge to characterize, for instance, the L-edge fine structures and chemical states. These mirrors will also find use in imaging solar instruments with a high spectral resolution operating aboard a spacecraft and in laboratory instruments for plasma diagnostics.

Published
2021

24. Search for high-strength multilayer free-standing film filters with high transmittance in the wavelength range of the 'water window' (2.3-4.4 nm)

Author

null Chkhalo N. I., null Tsybin N. N., null Salashchenko N. N., null Malyshev I.V., null Luchin V. I., null Lopatin A. Ya., null Garakhin S. A., and null Barysheva M. M.

Abstract

Some variants of the composition of multilayer absorption film filters with a high transmittance in the spectral region of the "water window" (2.3-4.4 nm) have been considered. Having created an ultimate pressure difference between the sides of free-standing films at which they are damaged, we compared the strength of 100 nm thick Ti-based multilayer filters with Al, Be, C interlayers and 100 nm thick V-based multilayer filters with Al interlayers. Sc and Cr was also considered as interlayers. Among the tested periodic multilayer structures, the best strength characteristics were demonstrated by Ti/Be (with a fraction of Ti in a period of about 0.6) and V/Al (with a fraction of V in a period of about 0.4) multilayer filters. Despite the fact that Ti/Be and V/Al filters are inferior in strength to Ti and V monolayer filters of the same thickness, these multilayer filters may be of interest, since they have either a higher transmittance in the "water window" (Ti/Be) or more high level of blocking of visible radiation (V/Al). Keywords: spectral region of the "water window" multilayer free-standing filters, ultimate pressure difference, film filter strength, transmittance in the soft x-ray, visible light blocking level.

Published
2022

41. Problem of roughness detection for supersmooth surfaces

Author

Barysheva, M. M., primary, Gribkov, B. A., additional, Vainer, Yu. A., additional, Zorina, M. V., additional, Pestov, A. E., additional, Platonov, Y. Y., additional, Rogachev, D. N., additional, Salashchenko, N. N., additional, and Chkhalo, N. I., additional

Published
2011
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