Investigation of the fields in an open waveguide with barrel-shaped mirrors
Investigation of the fields in an open waveguide with barrel-shaped mirrors
Yu.A. Pirogov and N.F. Ryapolov
The electrodynamics of an open axisymmetrical transmission line consisting of barrel-shaped mirrors is investigated. It is shown that the field distributions and the relations connecting them with the system parameters can be obtained from the scalar wave equation. Single-mode operation is obtained experimentally for different values of the diffraction parameter. The mechanism by which the fundamental mode is established in the line is considered. Good agreement between the experimental and theoretical curves is obtained.
Show AbstractSpectral analysis of polyharmonic regime of self-oscillators
Spectral analysis of polyharmonic regime of self-oscillators
V.V. Karpov
A special method is discussed for the analysis of polyharmonic regimes of selfoscillators. An example is presented of the application of this method to an oscillator with a soft limit cycle with a biharmonic force acting on the fundamental mode.
Show AbstractOccurrence of maxima of the combination type in mossbauer diffraction
Occurrence of maxima of the combination type in mossbauer diffraction
A.V. Kolpakov, E.N. Ovchinnikova, and R.N. Kuz'min
In this paper we discuss the occurrence of maxima of the combination type in the case that the scattering system is located in the fields of interactions with different symmetry. We examine the combination maxima which occur in the diffraction of Mossbauer radiation in the structure RFe_2.
Show AbstractDislocation structure of КСL crystals deformed by ultrasound
Dislocation structure of КСL crystals deformed by ultrasound
N.A. Tyapunina, E.V. Shtrom, and G.M. Zinenkova
The dislocation structure which occurs when ultrasound acts in crystals of KCl was investigated by the composite piezoelectric oscillator method at frequencies of 40-200 kHz with a relative deformation amplitude of ~$10^{-4}$. A difference was found in the development of the plastic deformation process over the frequency range investigated. An increase in the dynamic yield point was observed as the frequency was increased.
Show AbstractPolarization and energy flow of transverse waves propagating along the acoustic axes of crystals when external static fields are present
Polarization and energy flow of transverse waves propagating along the acoustic axes of crystals when external static fields are present
L.F. Baryshnikova and V.E. Lyamov
Using an expansion of the thermodynamic potential and the quasi-static approximation conditions, a system of equations is obtained determining the velocity of elastic waves in piezoelectric crystals acted upon by static fields. For certain classes of crystals, a nonlinear parameter is calculated which represents the elliptic polarization of the transverse waves propagating along the acoustic axes when a constant mechanical stress or an electric field acts on the crystal. An expression is obtained for the energy flow of acoustic waves in crystals in external fields.
Show AbstractExchange matrix element in the theory of atomic collisions
Exchange matrix element in the theory of atomic collisions
G.Ya. Korenman and S.I. Rogovaya
We develop a method of evaluating Born matrix elements of the exchange type from the Coulomb interaction operator with hydrogenous wave functions.
Show AbstractFeatures of internal modulation of the C0_2-laser
Features of internal modulation of the C0_2-laser
M.I. Zusman, V.N. Parygin, and A.G. Kukushkin
We conduct theoretical and experimental research on the internal modulation of the CO_2 laser. The frequency dependence of the amplitude of the varying component of the radiation intensity is shown to have a resonant character. The resonance frequency, the amplitude of the varying component of the intensity, and the width of the resonance curve are determined. Use of the resonant dependence permits attaining a gain in the amplitude of the modulating voltage 60-70 times greater than for external modulation.
Show AbstractThree-frequency parametric system as a twopole with negative parameters
Three-frequency parametric system as a twopole with negative parameters
V.N. Damgov and M.D. Karasev
A three-frequency reactive-active parametric modulator is considered, both theoretically and experimentally, which enables one to obtain a wide-band negative conductance and capacitance, inserted into the input circuit.
Show AbstractSelf-focussing of beams of elliptic cross section
Self-focussing of beams of elliptic cross section
K.D. Egorov and V.P. Kandidov
The stationary self-focussing of beams of elliptic cross section in modes which are close to critical is investigated numerically. The propagation process has an oscillating form. In supercritical modes the beam breaks up into filaments. A computational algorithm is described and its accuracy is investigated.
Show AbstractThe use of the method of impedance characteristics to analyze the propagation of waves in multilayer structures with absorption
The use of the method of impedance characteristics to analyze the propagation of waves in multilayer structures with absorption
A.V. Kozar, V.S. Kolesnikov, and Yu.A. Pirogov
A multilayer interference absorber (a system which completely absorbs incident energy in a thin layer of weakly absorbing material—the working layer) is analyzed using the method of impedance characteristics. The condition for resonance(practically complete) absorption is obtained as a function of the parameter of the working layer and the parameters of the multilayer structure for different modifications of the absorber, and the width of the absorption band is determined. The effect of small losses in the layers on the fundamental characteristics of the absorber is considered.
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