Propagation of perturbations in an elastic-plastic nondissipative medium
Propagation of perturbations in an elastic-plastic nondissipative medium
V.L. Popov
Propagation of elastic-plastic waves has been considered in terms of the simplest gauge theory of an isotropic elastic-plastic nondissipative continuum. It is shown that, in the course of time, a perturbation produced by a short impact breaks into six groups of waves having different character of propagation.
Show AbstractThe dynamics of a broad spectrum of oscillations in scattering of electromagnetic waves by a relativistic beam
The dynamics of a broad spectrum of oscillations in scattering of electromagnetic waves by a relativistic beam
Yu.V. Bobylev, V.A. Panin, A.P. Plotnikov
The nonlinear theory of scattering of multimode electromagnetic oscillations by a relativistic electron beam is examined. The principal stabilization mechanism for the instability that arises under anomalous Doppler effect is based on the following two effects: the beam retardation and the relativistic dependence of the plasma oscillations frequency of the beam on the amplitude. In the case of monochromatic pumping, the spectrum of the scattered wave is shown to broaden as the relativistic character of the beam grows. With a nonmonochromatic pumping, an effective excitation of the monochromatic signal wave takes place, with a process efficiency reaching 50-60%.
Show AbstractOn the theory of quasilinear relaxation of an electron beam emitting under conditions of collective Cerenkov effect
On the theory of quasilinear relaxation of an electron beam emitting under conditions of collective Cerenkov effect
M.V. Kuzelev, V.A. Panin
Multi-mode beam instabilities which develop in the conditions of the collective Cerenkov effect have been studied by quasilinear theory methods. The quasilinear approach is shown to be equivalent to the method of characteristics of the Vlasov equation as applied to the description of relaxation of the multi-mode beam instabilities. The excitation of a wide spectrum of electromagnetic oscillations by a dense beam in a retardation system has been studied. Besides, an equation of the Fokker-Planck type has been derived which describes the diffusion of electrons in a space of velocities, and also the laws of conservation of energy and momentum in the particle-field system.
Show AbstractDynamics of relativistic electrons in a nonadiabatic undulator with guide magnetic field
Dynamics of relativistic electrons in a nonadiabatic undulator with guide magnetic field
A.F. Aleksandrov, V.L. Vesnin, V.A. Kubarev, V.A. Cherepenin
A nonlinear theory is developed for a detailed investigation of the dynamics of relativistic electrons in nonadiabatic undulators with a guide magnetic field. The nonlinear resonance curves differ qualitatively from those obtained for adiabatic undulators. In the region of resonant magnetic fields, which are of the greatest interest, there are no stationary electron trajectories in both cases. The distinctive features of the electron dynamics are examined for active and passive systems. It is shown that the application of nonadiabatic undulators provides a much stronger twist of the beam as compared to adiabatic undulators and looks promising for microwave devices with transverse interaction, particularly for those using resonance scattering.
Show AbstractSynthesis of wideband multilayer metal-dielectric coatings
Synthesis of wideband multilayer metal-dielectric coatings
N.V. Grishina
The problem of obtaining wideband multilayer metal-dielectric coatings with desired spectral properties is considered. Using an earlier developed approach, we have synthesized high-performance heat-reflecting cut-off filters with silver and copper interlayers, and a low-reflectance coating with a transmission coefficient about 10% in the visible range, using nickel interlayers.
Show AbstractA method for improving the sensitivity of X-ray reflectometry
A method for improving the sensitivity of X-ray reflectometry
M.N. Orudzhaliev, V.A. Bushuev
A new method is proposed for determining the degree of roughness of a solid surface using the phenomenon of multiple X-ray total external reflection from the walls of a band-shaped waveguide. It is shown that the angular dependence of the waveguide transmission coefficient is more sensitive to the root-mean-square height of roughness than the curve of the single reflection coefficient. The dependence of the transmission coefficient on the X-ray guide parameters is analyzed.
Show AbstractThe Mott transition and electron pairing in a strong electromagnetic field
The Mott transition and electron pairing in a strong electromagnetic field
V.D. Blazhin
The feasibility of inducing a Mott's metal-insulator transition in narrow-band crystals by a strong constant or alternating electric field is shown. The tow-electron approximation has been applied to consider the problem of formation of a small-radius electron pair in a constant electric field in such crystals, and the idea of electromagnetic pumping, analogous to laser pumping, of superconducting condensates is formulated.
Show AbstractElectrical resistivity and Hall effect in amorphous $Cu_{1-x}Zr_x$ alloys in the $s-d$-model (the coherent locator approximation)
Electrical resistivity and Hall effect in amorphous $Cu_{1-x}Zr_x$ alloys in the $s-d$-model (the coherent locator approximation)
A.V. Vedyaev, A.B. Granovskii, I.Kh. Khalilov, S.A. Ninalalov, D.Kh. Imamnazarov, M.M. Gekhtman, Jr
The electronic structure, the electrical resistivity, and the Hall coefficient of amorphous $Cu_{1-x}Zr_x$ alloys were calculated in the framework of the coherent locator approximation for the $s-d$-model with consideration for the off-diagonal disorder. The calculation results on the concentration dependence of the electrical resistivity and the Hall coefficient are in agreement with the available experimental data.
Show AbstractFair-weather field and the baroelectric effect
Fair-weather field and the baroelectric effect
V.I. Grigor'ev, E.V. Grigor'eva
The electric field generated by the action of tidal forces on the Earth via the baroelectric effect, viz., the effect of redistribution of electrons in a nonuniformly stressed, chemically homogeneous isothermal conductor, was theoretically investigated. The field studied is compared with the fair-weather field over the Earth's surface and the conclusion is drawn that the existence of the fair-weather field can be explained in general terms without the assumption: that the Earth carries a considerable negative charge.
Show AbstractEmission of a sneutrino pair by a charged lepton in strong magnetic fields
Emission of a sneutrino pair by a charged lepton in strong magnetic fields
E.V. Merzonova, A.I. Studenikin, I.M. Ternov
The process of emission of a sneutrino pair by a charged lepton in an external magnetic field has been studied. Expressions for the probability of the $l’ \to l +\tilde{\nu_{l’}}+\tilde{\bar{\nu_l}}$ process in a strong magnetic field have been derived and the effect of one-dimensionalization is shown to take place in this case.
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