SovietRxiv · Open Access in English
Rediscovering the Soviet scientific archive, in English
25357 full-text translations 14926 English PDFs 22539 abstracts
Showing 50 of 2226 papers in Physics
The paper examines whether induced amplification of characteristic X-ray radiation can be achieved by producing an inverted population of inner atomic shells under X-ray pumping. It argues that, for certain inner-shell transitions and at densities close to those of solids, radiationless vacancy tran…
This paper proposes a representation of the Boltzmann equation in which the velocity distribution is expanded as an integral superposition of Maxwellian distributions with varying temperatures, reducing the collision term to a kernel in the corresponding parameter space. For spherically symmetric ho…
This paper analyzes the motion of test masses on circular equatorial orbits in the gravitational field of a rotating body, interpreting the resulting asymmetry between co-rotating and counter-rotating motion as a gravitational analogue of the Zeeman effect or partial dragging of local inertial frame…
The paper examines absorption of intense laser radiation by an electron gas through the multiphoton Compton effect, a mechanism expected to become important when electron oscillation energy in the laser field is relativistic. Using results for Compton scattering in an external circularly polarized p…
The paper studies integral relations for the Milne problem in radiative transfer in a half-space, including both the homogeneous case and the case with prescribed boundary insolation. It formulates the problem in an operator setting on functions over the unit sphere, recalls the associated character…
This paper examines the nucleon composition and excitation energies of nuclei undergoing photofission when bismuth-209, lead-208, and gold-197 targets are irradiated with photons of maximum energy 1 GeV. The authors derive fissioning-nucleus parameters from measured fragment kinetic energies and mas…
The paper addresses closure in turbulence theory for chains of equations governing joint probability distributions of velocity and related random variables. It proposes a closure approach based on an exact cumulant expansion of joint characteristic and probability distributions, in which approximate…
This paper analyzes the feasibility and optimal operating conditions of a single-pulse carbon dioxide laser intended to extract high pulse energy from a large gas volume. The authors argue that uniform electron production, preferably by photoionization of a small cesium additive, can overcome limita…
This paper studies one-dimensional nonstationary flows of a barotropic fluid with adiabatic index gamma equal to 2, a model relevant to several plasma, shallow-water, and nonlinear optical problems. Starting from the Euler equations, the authors show that this special case possesses an infinite sequ…
This paper investigates crater formation produced by millimeter-scale balls impacting strong rocks, porous rocks, pumice, and sand at velocities of 3 to 11.5 km/sec. Experiments measuring crater volume, shape, penetration behavior, and fragment ejection show that a simple proportionality between eje…
This paper develops a theoretical treatment of combination scattering of sound by spin waves in cubic ferromagnets, including both magnetostrictive interactions and the intrinsic magnetoelastic effect. For a longitudinal incident sound wave propagating perpendicular to a constant internal magnetic f…
This paper examines theoretical properties of solid-state lasers with very long resonators, motivated by the increased coupling of longitudinal modes, changes in spectral behavior, and possible approach to nonresonant feedback when resonator mode bands overlap. It proposes using an optical delay lin…
This paper develops an approximate selective modeling of the Sun’s gravitational field in Einstein’s theory by replacing selected Schwarzschild geodesics with non-geodesic curves in a flat four-dimensional model space. Imposing spherical symmetry, staticity, and Lorentz-type equations of motion, the…
This note reformulates the nonrelativistic hydrogen atom in terms of generators of the conformal group. Starting from the conformal commutation relations, the author constructs Heisenberg-representation generators, applies a canonical transformation to a light-cone constrained basis, and identifies …
The paper derives a fundamental equation for radiation acoustics by supplementing the linearized hydrodynamic equations for a quiescent homogeneous gas with radiative heat exchange under Kirchhoff’s law, neglecting scattering and mechanical radiation forces. It reduces the coupled system to fifth-or…
The paper develops a generalized Hartree-Fock treatment for a nonideal Bose gas at temperatures well below the critical temperature, using one-particle two-time temperature Green functions with anomalous averages included. It argues that the standard Hartree-Fock closure produces an unphysical gap i…
This paper examines the time dependence of the electron and ion current fractions in the near-cathode region of an arc discharge, focusing on the development of a cathode spot. Using a nonstationary diffusion model with ion production by electron-impact ionization near the cathode, the authors deriv…
This paper examines the kinetic theory of gases composed of nonspherical rigid molecules with rotational degrees of freedom, focusing on the mathematical structure of the corresponding Boltzmann-type equation. It derives the kinetic equation for rigid-body interactions as a limiting case of smooth r…
This study examines the evaporation kinetics of sodium chloride and the interaction of molecular beams containing NaCl monomers and Na2Cl2 dimers with tantalum and deposited sodium chloride films. Using a molecular beam apparatus with mass spectrometric detection, the authors measured Langmuir evapo…
Low frequency oscillations in a bounded low pressure helium plasma placed in an axial magnetic field are investigated experimentally with controlled variation of the end electrode potential. Using Langmuir probes and spectral measurements, the study shows that oscillations arise when the end potenti…
Stationary diffusion of particles near partially absorbing, or gray, bodies is formulated for linear transport equations and boundary conditions by decomposing the distribution function according to the number of nonabsorbing collisions with the body. The paper shows that the gray-body problem can b…
This paper reports measurements of the infrared absorption spectrum of liquid water at elevated temperatures, extending the accessible range to 4500 to 1500 cm−1 by using high-resistivity single-crystal silicon windows in a high-temperature cuvette. The authors describe corrections for thermal emiss…
The paper investigates whether vapors produced by intense irradiation of a solid surface can become opaque and shield the surface from further incident radiation. Using an explosive light source formed by a shock wave in argon or xenon, the authors irradiated targets of several materials and recorde…
This paper investigates short-wave radio pulses accompanying detonations of spherical solid high-explosive charges and examines whether their time characteristics can be used to infer ionization conditions behind the explosion shock wave. Radio emission was recorded at frequencies above 1 MHz for ch…
This paper develops a time-dependent theory for the generation power of organic dye lasers without assuming equality between gain and loss coefficients. Starting from rate equations for pump absorption, stimulated emission, losses, and population accumulation at a metastable level, it derives approx…
This paper reports a longitudinal pumping scheme for a tunable rhodamine 6G solution laser using a prism dispersion resonator, in which the pump and lasing beams are fully superposed in the active medium while losses at optical surfaces are minimized. Experiments with rhodamine 6G in isoamyl alcohol…
This paper derives a simple integral of the magnetic induction equation for an incompressible dissipative plasma by comparing it with the momentum-transfer equation including viscosity and Maxwell stresses. Under the conditions of zero total-pressure gradient and equality of kinematic viscosity and …
This paper develops a quantum theory of transverse conductivity and the Hall angle for polarons in three-dimensional disordered systems where dc transport is governed by nonadiabatic hopping between localized centers. Using Kubo-formula expressions with approximate averaging over local energy fluctu…
A quantum theory is developed for the frequency dependent conductivity of polarons in three dimensional disordered systems with spatially and energetically inequivalent localization centers, such as impurity conducting materials at low carrier concentrations and temperatures. Using a Kubo formula an…
This paper investigates the spatial and energy distributions of medium-energy ions scattered by a single crystal, using a specially constructed apparatus capable of varying incidence, target rotation, and polar and azimuthal scattering angles. Experiments with 30 keV argon ions incident on the (100)…
This paper investigates the nonstationary onset of thermal convection in a horizontal layer of viscous liquid heated from below, using time-resolved temperature measurements across the layer. Experiments with oils, glycerin solutions, alcohols, and water compare observed temperature profiles with th…
This paper examines how generally covariant observable, or assigned, quantities transform between arbitrarily moving reference frames in special and general relativity. Using Zelmanov’s chronometric invariant formalism, the authors represent each reference frame by a unit timelike vector field and a…
This paper examines how phase transitions in cyclopentane are manifested in low-temperature infrared absorption spectra, focusing on the temperature dependence of the 546 cm⁻¹ band width from 300 to 80 K. Measurements show changes in slope or discontinuous jumps at crystallization and at the crystal…
This paper reports experiments on nonmirror reflection of ultrasonic waves from a cadmium selenide piezosemiconductor crystal plate immersed in water, focusing on how illumination and an applied drift electric field affect amplification and absorption. Using pulsed 5 MHz ultrasound, measured polar r…
This paper reports experimental measurements of the passage of 8 mm radio waves through the region produced by small TG 50-50 explosive charges. Using horn-lens antennas and oscilloscope records of the received signal envelope, the authors analyze temporal oscillations in the scattered field with a …
The paper studies nonstationary and stationary self-similar waves in cold plasma configurations with electric and magnetic fields that scale with radius, including cylindrical filaments, plane layers, spherical clouds, and plasma jets. By applying similarity substitutions to Maxwell’s equations and …
This paper examines the stability of a low density plasma pinch in the regime where the electron drift velocity exceeds the ion sound speed and the usual one fluid magnetohydrodynamic approximation is no longer adequate. Using ideal two fluid magnetohydrodynamic equations with the magnetic field eff…
This paper addresses the Gibbs paradox for ideal gases by examining cases in which the distinguishability of the gases varies continuously rather than discretely. It first treats gases that are themselves mixtures of common components and shows that the entropy of mixing is a continuous function of …
This paper examines topological restrictions on spacetime manifolds proposed for cosmological models, including conditions related to indefinite metrics, causality, orientability, and discrete symmetry noninvariance. It argues that, by analogy with restrictions derived from CP noninvariance, CT noni…
The paper discusses a nonlinear ionospheric effect in which powerful radio waves heat electrons, alter the effective electron collision frequency, and thereby create artificial gradients of the refractive index in the lower ionosphere. Using Fresnel-type estimates for quasi-longitudinal propagation,…
This paper investigates the origin of chaotic spiking in solid-state lasers through experiments on traveling-medium lasers using ruby, neodymium glass, and calcium tungstate doped with neodymium. By moving the active medium along the laser axis and limiting the transverse working region with diaphra…
This paper examines how the interaction between weakly coupled subsystems should be treated when constructing a stationary nonequilibrium density matrix. Using a spin system in constant and alternating magnetic fields as an example, it introduces the invariant part of the interaction Hamiltonian int…
A method is proposed for determining dislocation velocities in photochemically colored ionic crystals from the deformation luminescence produced during pulsed loading. The approach relates the number of emitted light quanta to the area swept by moving dislocations, using measured or previously deter…
The paper argues that a vacuum-like state of matter with energy momentum tensor proportional to the metric and equation of state p equals minus the energy density can serve as the initial state for any of the three Friedmann cosmological models. It analyzes the causal and quantum limits of such a me…
This paper analyzes the pinch effect in a bipolar semiconductor plasma when one or both carrier species are strongly degenerate, a regime not covered by the usual nondegenerate gas model. For an infinite plate carrying longitudinal current, the carrier distribution is reduced under quasineutrality a…
This note analyzes features of the interband Faraday effect in heavily doped semiconductors near the absorption edge, focusing on how electron degeneracy and randomly distributed impurity potentials modify ellipticity and rotation. Using a simple band model with Landau-level summation and a classica…
This paper formulates a variational and Hamiltonian representation for the equations of ideal magnetohydrodynamics, extending Davydov’s canonical treatment of ideal fluid hydrodynamics. By introducing a decomposition of the velocity field in terms of the density, magnetic field, scalar potential, an…
The paper examines the “chain effect” in glancing scattering of argon ions by the [110] atomic chains on the (100) face of a copper single crystal. Using numerical calculations based on earlier scattering models, it analyzes how the reflected ion energy as a function of scattering angle changes with…
The paper examines quantities constructed from the Ricci tensor and a separated term containing second derivatives of the metric, arguing that in harmonic coordinates the resulting quantities can be interpreted as gravitational stresses. It derives a decomposition of the Einstein tensor into two par…
This paper examines the use of Stark broadening of hydrogen spectral lines as a noncontact optical diagnostic of electric fields associated with turbulent plasma heating by direct discharge current. The authors derive and apply criteria distinguishing quasistatic ion-acoustic fields from high-freque…
