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Spectral dependence of nonlinear radiation trapping in high density atomic vapor
Journal of Quantitative Spectroscopy and Radiative Transfer. 2020. Vol. 256. P. 1–6.
Sautenkov V., Saakyan S., Zelener B.
We report an experimental study of nonlinear radiation trapping in a high-density rubidium vapor where the self-broadening of the resonance transitions 5S1/2 − 5P3/2 exceeded the Doppler broadening. The atomic number densities used were N1 = 3 × 10^16 cm^−3 and N2 = 8 × 10^16 cm^−3. In our experiment, a signal of retro-fluorescence was recorded. By means of scanning a single mode laser near the resonance transition, spectral dependence of the effective radiative lifetime was measured with different values of the excitation optical power. Growth of the effective radiative lifetime with increasing power was observed. Within the framework of a simple model, it was shown that incoherent optical saturation can be increased by the number of photon absorption-reemission in the radiation transfer process. Further experiments are suggested.
Bisnovatyi-Kogan G., Kondratyev I., Moiseenko S. G., International Journal of Modern Physics A 2025 Vol. 40 No. 7 Article 2550018
Bright transient objects in different wave bands have been discovered in recent years.
To explain these short (from ms to s), and very powerful events, different models, galactic and
extragalactic, have been considered. One of the popular models is based on the suggestion of
transformation of the magnetized plasma blob, presumably a magnetohydrodynamic (MHD)
shock wave, moving with relativistic ...
Added: May 11, 2026
Торопина О. Д., Бисноватый-Коган Г. С., Moiseenko S. G., Astronomy Reports 2025 Vol. 69 No. Suppl. 1 P. 80–90
The results of MHD simulations of supersonic astrophysical and laboratory jets in an external
poloidal magnetic field (Br,Bz) taking into account the rotation of the matter, are presented. The ejected
matter is collimated by the magnetic field, the degree of collimation and the flow structure depend on the
relation between of the magnetic field induction and the angular ...
Added: May 11, 2026
Morozov E. V., Demin A. S., Borovitskaya I. V. et al., Inorganic Materials: Applied Research 2026 Vol. 17 No. 3 P. 619–626
This article presents the results of experiments on the impact of powerful pulsed ion-plasma and
electron flows generated in the working chamber of the Plasma Focus PF-5M installation during each highvoltage
discharge on a model aluminum alloy B95. It is shown that the general characteristics of the alloy’s
damage upon exposure to pulsed flows of helium ions (HI) ...
Added: May 4, 2026
Ponomarev A., Aleksandrov N., Plasma Physics Reports 2026 Vol. 52 No. 3 P. 367–378
An approximate method for calculating drift velocity and other kinetic coefficients of heavy ions
in a light gas is generalized to gaseous mixtures. Obtained equations are used to calculate the mobilities of
and ions, as well as rate constants for inelastic ion–molecule processes with these ions in helium with
small additions of O2 under an electric field. Calculated ...
Added: April 27, 2026
Domrin V. I., Malova H. V., V. Yu. Popov et al., Cosmic Research 2026 Vol. 64 No. 2 P. 238–252
During magnetospheric perturbations a relatively thin current sheet with thickness about several
proton gyroradii forms in the Earth’s magnetotail. In a framework of the kinetic model describing current
sheet thinning in the magnetotail, the processes of its formation are investigated depending on the normal
magnetic field magnitude which affects both the current sheet structure and particle dynamics within ...
Added: April 27, 2026
Tsareva O. O., Malova H. V., V. Yu. Popov et al., Plasma Physics Reports 2026 Vol. 52 No. 2 P. 179–185
The influence of asymmetry of plasma sources on the structure and spatial localization of a superthin
current sheet (STCS) supported by demagnetized electrons is studied using a self-consistent model. The
simulation takes into account the presence of a single plasma source in the northern hemisphere, which
makes the plasma flow asymmetric. It is demonstrated that the asymmetry of ...
Added: April 27, 2026
П.А.Беспалов, О.Н. Савина, Геомагнетизм и аэрономия 2025 Т. 65 № 5 С. 620–628
Several basic models of frequency dynamics in quasi-periodic VLF emissions with spectral form repetition
periods from 10 to 300 s are considered. In all cases, we are talking about manifestations of cyclotron instability
of electron radiation belts thet are well described within the framework of the plasma magnetospheric maser
theory based an the averaged self-consistent system of quasi-linear ...
Added: April 25, 2026
Bondarenko G.G., Fisher M. R., Kristya V. I., Bulletin of the Russian Academy of Sciences: Physics 2026 Vol. 90 No. 4 P. 572–576
A model of the cathode layer of a glow gas discharge with a thin dielectric film on a fraction of the
cathode’s working surface is formulated. It is shown that a glow discharge most rapidly transits to an arc discharge,
accompanied by a significant increase in discharge current density and a decrease in cathode voltage
drop, if the ...
Added: April 25, 2026
Lu X., Tognazzi A., Klimov V. et al., Plasmonics 2026 Vol. 21 P. 1503–1512
Plasmonic nanostructures typically exhibit shifts in their resonant wavelength in response to changes in the refractive index of the surrounding medium. This limits their applications in scenarios requiring stable optical resonances. Here we present a metallic-dielectric hybrid metasurface that exhibits stable multi-wavelength resonance even if the refractive index of its surrounding varies. To quantitatively evaluate the stability of ...
Added: April 22, 2026
Shchur L., Antonov D., Burovski E., International Journal of Bifurcation and Chaos in Applied Sciences and Engineering 2026 P. 1–9
We present a simple model that simulates the possible influence of one society on another. Specifically, two societies evolve deterministically according to the well-known Nowak-May spatial game with the addition of mutual influence through connections that reflect the current states of the societies. This may be related to the influence of a global information resource ...
Added: April 20, 2026
Qin X., Deng Y., Shchur L. et al., / Series arXiv "math". 2026. No. 2603.02962.
We perform a Monte Carlo analysis of the Ising model on many three-dimensional lattices. By means of finite-size scaling we obtain the critical points and determine the scaling dimensions. As expected, the critical exponents agree with the three-dimensional Ising universality class for all models. The irrelevant field, as revealed by the correction-to-scaling amplitudes, appears to ...
Added: April 20, 2026
Pilé I., Deng Y., Shchur L., / Series arXiv "math". 2026. No. 2604.10254.
We investigate the spatial overlap of successive spin configurations in Markov chain Monte Carlo simulations using the local Metropolis algorithm and the Svendsen-Wang and Wolff cluster algorithms. We examine the dynamics of these algorithms for two models in different universality classes: the Ising model and the Potts model with three components. The overlap of two ...
Added: April 20, 2026
Doronin S. V., Budkov Y., Current Opinion in Electrochemistry 2026 Vol. 57 Article 101853
The electric double layer (EDL) governs charge distribution at electrode–electrolyte interfaces, controlling reaction kinetics and energy storage performance. This mini review surveys the evolution of EDL theory—from the classical Gouy-Chapman-Stern framework to modern coupled quantum-continuum schemes that integrate electronic structure with statistical mechanics. We show how modified Poisson–Boltzmann (mPB) formu-lations incorporating finite ion size, dielectric ...
Added: April 19, 2026
Nikolai N. Kalikin, Petr E. Brandyshev, Yury A. Budkov, Journal of Chemical Physics 2026 Vol. 164 No. 15 Article 154904
This study presents a mean-field theory for zwitterionic polymer solutions confined within attractive slit-like nanopores. Building upon our prior model for self-coacervation [Budkov et al., Soft Matter 19, 3281–3289 (2023)], we demonstrate that strong electrostatic dipole–dipole correlations between monomeric units, coupled with attraction to pore walls, can induce capillary-driven liquid–liquid phase separation inside the pore—a ...
Added: April 18, 2026
Moiseev E., D.A. Masyutin, I.A. Melnichenko et al., Optics and Laser Technology 2026 Vol. 201 No. 115289 Article 115289
Lasing at a wavelength near 255 nm is demonstrated in AlGaN whispering gallery mode microlasers with radii ranging from 1 to 3 µm fabricated on sapphire substrates, representing one of the shortest-wavelength realizations of microdisk lasers on this technologically relevant platform. The minimum threshold energy was 8.8 pJ (power density ≈ 280 kW/cm2) for a microlaser with a ...
Added: April 18, 2026
A. V. Pereskokov, Theoretical and Mathematical Physics 2026 Vol. 226 No. 3 P. 470–484
We consider the spectral problem for a hydrogen atom in orthogonal electric and magnetic fields with
an additional self-consistent field. We obtain an asymptotic expansion of self-consistent energy levels.
We find an asymptotic expansion of asymptotic eigenfunctions near the sphere |q| = 2. We calculate the
asymptotics of their norm in the space L2(R3). ...
Added: April 12, 2026
Sautenkov V., Saakyan S., Bobrov A. et al., Journal of Quantitative Spectroscopy and Radiative Transfer 2026 Vol. 351 Article 109796
We discuss nonlinear spectra of selective reflection from high-density rubidium atomic vapor, where the self-broadening of the resonant transition 5S1/2 - 5P3/2 dominates over the Doppler width. In the experiments, the hole-burning technique with probe and pump lasers is used. The reflection of weak probe beam is investigated at four atomic densities in the range ...
Added: January 11, 2026
Чернышов Д. П., Satanin A., Shchur L., / Series arXiv "math". 2025.
We investigate the boundary separating regular and chaotic dynamics in the generalized Chirikov map, an extension of the standard map with phase-shifted secondary kicks. Lyapunov maps were computed across the parameter space (K,K(α, τ)) and used to train a convolutional neural network (ResNet18) for binary classification of dynamical regimes. The model reproduces the known critical ...
Added: November 21, 2025
Sautenkov V., Saakyan S., Bobrov A. et al., Journal of Quantitative Spectroscopy and Radiative Transfer 2024 Vol. 328 Article 109153
We study the resonant saturation of selective reflection at the interface between a transparent dielectric and high-density rubidium vapor on the D2-line. Our estimates suggest that, within the selected atomic density range, the dipole–dipole self-broadening of the line can vary from 13.2 to 39.6 GHz. Two tunable lasers are used as sources of pump and ...
Added: March 10, 2025
Kagan M., Silkin V. M., Efremov D. V., / Series arXiv "math". 2024. No. 2411.12836.
In this study, we analyze the dielectric function of high-Tc cuprates as a function of doping level, taking into account the full energy band dispersion within the CuO2 monolayer. In addition to the conventional two-dimensional (2D) gapless plasmon mode, our findings reveal the existence of three anomalous branches within the plasmon spectrum. Two of these branches ...
Added: November 27, 2024
Influence of anisotropy on the study of critical behavior of spin models by machine learning methods
Sukhoverkhova D., Shchur L., / Series arXiv "math". 2024. No. 2410.14523.
In this paper, we applied a deep neural network to study the issue of knowledge transferability between statistical mechanics models. The following computer experiment was conducted. A convolutional neural network was trained to solve the problem of binary classification of snapshots of the Ising model's spin configuration on a two-dimensional lattice. During testing, snapshots of ...
Added: October 21, 2024
Mozolenko V., Fadeeva Marina, Shchur L., / Series arXiv "math". 2024. No. 2405.10865.
The development of new algorithms for simulations in physics is as important as the development of new analytical methods. In this paper we present a comparison of the recently developed microcanonical population annealing (MCPA) algorithm with the rather mature Wang-Landau algorithm. The comparison is performed on two cases of the Potts model exhibiting a first ...
Added: May 20, 2024
Kagan M., Аксёнов С. В., / Series Research Square "Research Suqare". 2024. No. 1.
We study different resonances (first of all of the Fano type) in the interference device formed by the Aharonov-Bohm ring with superconducting (SC) wire in the topologically nontrivial state playing a role of a bridge between top and bottom arms. We analyze Majorana modes on the ends of the SC wire and show that the collapse of the ...
Added: April 10, 2024
Zelener B. B., Vilshanskaya E. V., Morozov N. V. et al., Physical Review Letters 2024 Vol. 132 No. 11 Article 115301
In this Letter we discuss our approach that makes possible creation of the steady-state ultracold plasma having various densities and temperatures by means of continuous two-step optical excitation of calcium atoms in the magneto-optical trap. A strongly coupled ultracold plasma can be used as an excellent test platform for studying many-body interactions associated with various ...
Added: March 16, 2024