Персона: Городничев, Евгений Евгеньевич
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Институт лазерных и плазменных технологий
Стратегическая цель Института ЛаПлаз – стать ведущей научной школой и ядром развития инноваций по лазерным, плазменным, радиационным и ускорительным технологиям, с уникальными образовательными программами, востребованными на российском и мировом рынке образовательных услуг.
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Городничев
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Евгений Евгеньевич
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- ПубликацияТолько метаданныеA viscosity effect on development of instabilities at the interface between impacted plates(2019) Ilnitsky, D. K.; Gorodnichev, K. E.; Serezhkin, A. A.; Kuratov, S. E.; Gorodnichev, E. E.; Городничев, Евгений ЕвгеньевичThe problem of two semi-infinite plates under impact is studied both theoretically and numerically. Initially, one plate has the perturbed density field with uniform distribution of pressure. We demonstrate that various regimes of instabilities development in plates are guided by the appropriate initial conditions. A viscosity effect on instabilities growth is analyzed. Particularly, the minimal wavelength of an initial perturbation, for which viscosity effect is negligible, is obtained. The performed numerical simulations support our theoretical insights.
- ПубликацияОткрытый доступПоляризационные эффекты при многократном рассеянии света в средах с крупными неоднородностями(НИЯУ МИФИ, 2011) Городничев, Е. Е.; Городничев, Евгений Евгеньевич
- ПубликацияТолько метаданныеCoherent backscattering of light from a Faraday medium(2022) Gorodnichev, E. E.; Kondratiev, K. A.; Rogozkin, D. B.; Городничев, Евгений Евгеньевич; Кондратьев, Кирилл Александрович; Рогозкин, Дмитрий Борисович© 2022 American Physical Society.We study coherent backscattering (CBS) of light from a magnetoactive medium doped by Mie particles. A novel version of the CBS diffusion theory is developed, which takes into account both the Faraday effect and the effect of circular polarization memory specific to Mie scattering. The theory is based on a system of coupled diffusion equations for two slowly decaying cooperon modes arising from interference of waves with coinciding helicities. The impact of a magnetic field on CBS is shown to be controlled by the ratio of the helicity-flip scattering cross section to the transport scattering one. If this ratio is small, the CBS can exhibit unusual features first found experimentally by R. Lenke, R. Lehner, and G. Maret [Europhys. Lett. 52, 620 (2000)EULEEJ0295-507510.1209/epl/i2000-00483-y]. In the magnetic field parallel to the sample surface, the peak of coherent backscattering for circularly polarized light is shifted from the exact backward direction, while, for linearly polarized light, it splits in two ones for both co- and cross-polarization channels, and the backscattered waves acquire circular polarization. Saturation of the magnetic field dependence of the CBS cone occurs in the magnetic field normal to the surface. If the above ratio is close to unity (Rayleigh scattering) all these features disappear, and the effect of the magnetic field on the CBS angular profile is reduced to the universal law studied previously. The results obtained are in good quantitative agreement with the available Monte Carlo simulation and experimental data.
- ПубликацияТолько метаданныеCircular dichroism in the presence of resonant Mie scatterers(2019) Gorodnichev, E. E.; Rogozkin, D. B.; Городничев, Евгений Евгеньевич; Рогозкин, Дмитрий БорисовичUnpolarised light propagation is considered in a circularly dichroic medium with optically isotropic Mie-particles. The degree of passed radiation polarisation is calculated under the assumption that multiple scattering in such a system occurs in the spatial diffusion regime. It is shown that introducing Mie particles into a homogeneous sample with natural optical activity can noticeably enhance the observed circular dichroism, namely, increase a difference between the intensities of right- and left-handed polarised light passed through the medium. If the first Kerker condition is fulfilled for Mie particles, then the effect can be almost ten times stronger as compared to the case of a homogeneous sample.
- ПубликацияОткрытый доступOptical analogue of the Aharonov-Bohm effect in a magneto-active medium(2021) Gorodnichev, E. E.; Rogozkin, D. B.; Городничев, Евгений Евгеньевич; Рогозкин, Дмитрий Борисович© 2021 Institute of Physics Publishing. All rights reserved.We study an optical analogue of the Aharonov-Bohm effect in a magneto-active medium containing a wire with current. It is shown that the phase shift between the light rays propagating around the wire is proportional to the current strength. The current acts as a magnetic flux in the conventional Aharonov-Bohm effect. Therefore the differential cross section of light scattering from the vortex of the magnetic field created by the linear current proves to be a periodic function of the current strength.
- ПубликацияОткрытый доступCoherent backscattering from an ensemble of Mie-particles immersed in a magneto-active medium(2020) Gorodnichev, E. E.; Rogozkin, D. B.; Городничев, Евгений Евгеньевич; Рогозкин, Дмитрий Борисович© Published under licence by IOP Publishing Ltd.We show that coherent backscattering of light from a disordered sample in a magnetic field can exhibit unusual features. The helicity retention in scattering from particles of the sample underlies these features. In the magnetic field parallel to the sample surface, the peak of coherent backscattering of circularly polarized light shifts from the backward direction by an angle proportional to the magnetic field strength. For linearly polarized light the coherent backscattering cone splits into two ones. The results obtained correlate well with the available experimental data.
- ПубликацияОткрытый доступWeak Localization of Light in a Magneto-active Medium(2023) Gorodnichev, E. E.; Rogozkin, D. B.; Городничев, Евгений Евгеньевич; Рогозкин, Дмитрий БорисовичWe study an optical analogue of the Aharonov-Bohm effect in a magneto-active medium containing a wire with current. It is shown that the phase shift between the light rays propagating around the wire is proportional to the current strength. The current acts as a magnetic flux in the conventional Aharonov-Bohm effect. Therefore the differential cross section of light scattering from the vortex of the magnetic field created by the linear current proves to be a periodic function of the current strength.
- ПубликацияОткрытый доступPropagation and Depolarization of a Short Pulse of Light in Sea Water(2020) Gorodnichev, E. E.; Kondratiev, K. A.; Kuzovlev, A. I.; Rogozkin, D. B.; Городничев, Евгений Евгеньевич; Кондратьев, Кирилл Александрович; Кузовлев, Александр Иванович; Рогозкин, Дмитрий БорисовичWe present the results of a theoretical study of underwater pulse propagation. The vector radiative transfer equation (VRTE) underlies our calculations of the main characteristics of the scattered light field in the pulse. Under the assumption of highly forward scattering in seawater, three separate equations for the basic modes are derived from the exact VRTE. These three equations are further solved both within the small-angle approximation and numerically. The equation for the intensity is analyzed for a power-law parametrization of the wings of the sea water phase function. The distribution of early arrival photons in the pulse, including the peak intensity, is calculated. Simple relations are also presented for the variance of the angular distribution of radiation, the effective duration of the signal and other parameters of the pulse. For linearly and circularly polarized pulses, the temporal profile of the degree of polarization is calculated for actual data on the scattering matrix elements. The degree of polarization is shown to be described by the self-similar dependence on some combination of the transport scattering coefficient, the temporal delay and the source-receiver distance. Our results are in agreement with experimental and Monte-Carlo simulation data. The conclusions of the paper offer a theoretical groundwork for application to underwater imaging, communication and remote sensing.
- ПубликацияОткрытый доступDiffusion of light through a disordered ensemble of resonant Mie-particles embedded in a medium with circular dichroism(2019) Gorodnichev, E. E.; Rogozkin, D. B.; Городничев, Евгений Евгеньевич; Рогозкин, Дмитрий Борисович© Published under licence by IOP Publishing Ltd.We study transmission of unpolarized light (incoherent superposition of right-hand circular and left-hand circular polarized waves) through an optically active medium doped by scattering Mie-particles. The medium is assumed to possess circular dichroism. Within the spatial diffusion approximation, the degree of circular polarization of the transmitted radiation is calculated. It is shown, that in the presence of scatterers a significant increase in the circular polarization compared to the medium with no scatterers can be observed.
- ПубликацияТолько метаданныеTheoretical and numerical analysis of density perturbation development induced by high velocity impact(2020) Gorodnichev, K.; Zakharov, P.; Kuratov, S.; Menshov, I.; Gorodnichev, E.; Городничев, Евгений Евгеньевич© 2020 Author(s).The problem of high velocity impact between two solid plates where one of them has a non-uniformly disturbed density field is studied. The nature of an initial perturbation here differs from one considered in the classical Richtmyer-Meshkov instability (RMI). We consider the instability that develops from the initial perturbations of the density field with a flat interface between plates, while RMI is triggered by a shock passing through the corrugated interface. The structure of perturbation fields generated in the plates due to impact and the interface evolution are studied via the analytic linear and nonlinear models for normal modes using the Euler equations for compressible fluids and appropriate boundary conditions. Such analysis reveals three different regimes in which the generated disturbances can develop depending on the direction of the perturbation wave vector. The obtained theoretical findings are in good quantitative agreement with our detailed numerical simulations.