共查询到20条相似文献,搜索用时 203 毫秒
1.
A. V. Zakharov 《Russian Physics Journal》1985,28(12):992-997
The combined behavior of gravitational and electromagnetic perturbations in the radiation-dominated plasma of an isotropic universe is considered. It is shown that transverse electromagnetic waves and vector and tensor gravitational perturbations are independent of one another. The propagation of transverse electromagnetic waves during the lepton and radiation-dominated phases is determined. It is shown that the gravitational perturbations help to excite longitudinal electromagnetic fields in the radiation-dominated plasma.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 49–54, December, 1985. 相似文献
2.
The beat heating of a magneto-plasma by two antiparallel electromagnetic waves at different temperatures is examined. The effects of plasma temperature, plasma electron collisions, plasma ion collisions and magnitude and direction of the magnetic field on the excitation of plasma electron waves and plasma ion waves are studied. A formula for the power absorption density of the plasma by using Maxwell's equations in conjuction with continuity and momentum equation. including collisions and pressure tensor terms, is derived. The contribution of the plasma temperature to the power absorption density, both at low and high beat frequencies, of the collisional and the non-collisional magnetised plasmas is found very significant and is illustrated numerically. The inclusion of pressure tensor term in the momentum equation is also found to cause characteristic changes in the power absorption density of the plasma with the orientation of magnetic field. 相似文献
3.
O. G. Chkhetiani 《Journal of Experimental and Theoretical Physics》2004,99(2):328-339
The problem of determining the effective conductivity tensor of a magnetoactive turbulent plasma is considered in the approximation of isolated particles. Additional gyrotropic terms are shown to appear in the conductivity tensor in the presence of mean, nonzero magnetic helicity. The dispersion of propagating electromagnetic waves changes, additional modes and additional rotation of the polarization plane appear, and the waves can be amplified. The properties acquired by a plasma with helicity are similar to those observed in chiral and bianisotropic electrodynamic media. 相似文献
4.
Kalluri Dikshitulu Shrivastava R. K. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1974,2(4):206-210
The oscillations in the power reflection coefficient as a function of the normalized slab velocity are shown for electromagnetic waves obliquely incident on a relativistically moving uniaxial plasma slab with an infinitely strong magneto-static field parallel to the slab boundaries. This paper also summarizes and concludes the sequence on the reflection and transmission of electromagnetic waves obliquely incident on relativistically moving uniaxial and isotropic plasma slabs. 相似文献
5.
Summary The well-known anomalous absorption of transverse electromagnetic waves near the resonance point of a plasma surface is described
as a phenomenon of radiative damping of waves. Reflections from a sharp plasma surface and from smoothly inhomogenous plasma
are considered separately. It is shown that during the reflection ofE-waves from the surface of a smoothly bounded inhomogeneous plasma, radiative damping occurs in the reflecting point as a
result of longitudinal plasma waves emission and it is also shown that anomalous absorption of electromagnetic waves in the
long-wavelength limit is significant as well as in the short wavelength. 相似文献
6.
《Waves in Random and Complex Media》2013,23(3):336-348
Abstract Using dielectric permittivity tensor of the magnetized prolate plasma, the scattering of long wavelength electromagnetic waves from the mentioned object is studied. The resonance frequency and differential scattering cross section for the backward scattered waves are presented. Consistency between the resonance frequency in this configuration and results obtained for spherical plasma are investigated. Finally, the effective factors on obtained results such as incident wave polarization, the frequency of the incident wave, the plasma frequency and the cyclotron frequency are analyzed. 相似文献
7.
A. V. Gurevich 《Radiophysics and Quantum Electronics》1972,15(1):5-10
The perturbation of the ionization and of the electron temperature is considered in a plasma in a field of strong electromagnetic waves. It is shown that the intensified absorption of the waves in the region of their reflection leads to the appearance of the moving perturbations of the plasma ionization. The conditions governing the development of moving perturbations are determined along with their velocity and spatial structure. It is demonstrated that in a weakly inhomogeneous plasma such perturbations appear in the neighborhood of the reflection point of the waves and move toward the wave so as to cause perturbation. This leads to the generation of nondecaying nonlinear oscillations in the plasma. The frequency of the oscillations is determined, and it decreases with increasing absorbed power of the waves.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 15, No. 1, pp. 11–18, January, 1972.The author is indebted to V. L. Ginzburg for his useful discussions. 相似文献
8.
J. D. LAWSON 《中国物理C(英文版)》1981,5(3):339-345
Many Suggestions have been made for accelerating particles in the intense fields associated with laser light. Those which rely on direct interaction with the laser field in vacuo (as opposed to acceleration in a plasma medium) are examined and their fundamental limitations discussed. Three schemes are considered, the first of these utilizes slow electromagnetic waves near a surface, the second relies on a fast electromagnetic wave with "phase jumps" and the third used parametric interaction with particles moving on a modulated orbit. 相似文献
9.
We consider the effect of Coulomb correlation on the low frequency part of the spectrum of electromagnetic waves propagating in a non‐ideal electron‐ion plasma. The dielectric tensor constructed by means of the theory of moments is employed. 相似文献
10.
We investigate transverse electromagnetic waves propagating in a plasma influenced by the gravitational field of the Schwarzschild-de
Sitter black hole. Applying 3+1 spacetime split we derive the relativistic two-fluid equations to take account of gravitational
effects due to the event horizon and describe the set of simultaneous linear equations for the perturbations. We use a local
approximation to investigate the one-dimensional radial propagation of Alfvén and high frequency electromagnetic waves. We
derive the dispersion relation for these waves and solve it for the wave number k numerically. 相似文献
11.
Russian Text Ignored 《等离子体物理论文集》1978,18(4):231-240
The stability of the electromagnetic plasma confinement by powerful external s-polarized pump waves is considered. The parametric excitation of standing electromagnetic waves along the plasma boundary with frequencies close to the frequency of the pump wave leads to a periodic density modulation of the plasma boundary. The density disturbances along the direction of the external wave field are connected to the excitation of transverse p-polarized surface waves while the modulation in the direction perpendicular to the pump field are created by the parametric interaction between the external wave and s-polarized trapped leaking oscillations. Only when the leaking waves are excited the scale length of the modulation is larger than half the free space wave length of the incident radiation. 相似文献
12.
Solitary waves in relativistic electromagnetic plasmas are
obtained numerically. The longitudinal momentum of electrons has
been taken into account in the problem. It is found that in the
moving frame with electromagnetic field propagating the solitary
waves can exist in both cases, where the vector potential
frequency is larger or smaller than the plasma characteristic frequency. 相似文献
13.
The effect of spatial dispersion on the electromagnetic properties of a metamaterial consisting of a three-dimensional mesh of crossing metallic wires is reported. The effective dielectric permittivity tensor epsilon(ij)(omega, k) of the wire mesh is calculated in the limit of small wavenumbers. The procedure for extracting the spatial dispersion from the omega versus k dependence for electromagnetic waves propagating in the bulk of the metamaterial is developed. These propagating modes are identified as similar to the longitudinal (plasmon) and transverse (photon) waves in a plasma. Spatial dispersion is found to have the most dramatic effect on the surface waves that exist at the wire mesh-vacuum interface. 相似文献
14.
A. Cemal Eringen 《Foundations of Physics》2006,36(6):902-919
This paper introduces a continuum microelectromagnetic theory (also called micromorphic electromagnetic theory), to discuss electromagnetic phenomena in bodies with microstructures. Balance laws of microelectromagnetic media of the first-grade are given. Constitutive equations are developed. The field equations are obtained . It has been shown that, this theory gives rise to several new vector and tensor waves. A theorem of conservation of energy (Poynting type) is proved. Dispersion relations are obtained for both vector and tensor waves. Relations of tensor waves to microscopic phenomena (such as spin waves) are discussed. 相似文献
15.
We investigate generation and radiation of waves at combined frequencies from an arbitrary inhomogeneous, isotropic plasma layer, when electromagnetic waves are obliquely incident on it to interact with a surface wave at the plasma boundary. This interaction has been described for both S- and P-polarized waves. We consider a warm plasma layer with thickness very small as compared to the wavelengths of oscillations. It is shown that generated waves are strongly amplified, compared to cold plasma, when phase velocities of generated waves approaches the electron thermal velocity. Waves are not emitted when P-polarized waves are incident perpendicular onto the plasma layer. 相似文献
16.
17.
We give the Lagrangian of a system of moving charged particles up to the fourth approximation in 1/c neglecting dipole radiation of the system. In this case the appearance of the electromagnetic waves (quadrupole radiation) by moving charges occurs in the fifth approximation in 1/c. 相似文献
18.
W. B. Bonnor 《International Journal of Theoretical Physics》1970,3(1):57-65
I give solutions of the Einstein-Maxwell equations describing charge moving with the speed of light,c. The motion generates plane-fronted electromagnetic and gravitational waves. Charges moving parallel to each other with speedc do not interact; nor do they interact with parallel light beams. 相似文献
19.
B. Jazi M. Nejati A. Salehi 《International Journal of Infrared and Millimeter Waves》2006,27(11):1469-1495
By using the Fourier components of dielectric tensor elements of cold collisionless degenerate plasmas, the dispersion relation
of electromagnetic waves in a cylindrical metallic waveguide with a degenerate plasma column protected by an annular dielectric
layer are obtained. The permissible frequency regions for slow and fast waves in E-mode (TM) are presented. Furthermore, the
graph of cutoff frequency versus the radius of plasma column for the fast waves is investigated. In addition, the time growth
rate for excitation of symmetric slow E-modes (TM) by a thin annular relativistic electron beam (TAREB) is studied. The graph
of time growth rate respect to radius of dielectric layer and accelerating voltage are presented.
PACS No. 52.25. 相似文献
20.
We study theoretically the influence of a circular metallic waveguide with a longitudinal magnetic field on the synchrotron radiation of a point electric charge moving along a helical trajectory coaxial with the waveguide axis. The main attention is focused on the analysis of the energy characteristics of radiation of electromagnetic E and H waves. We derive the formulas for the radiation powers of E and H waves. It is shown that, under certain conditions, slowly moving electric charges do not radiate any of these electromagnetic waves in the circular waveguide. 相似文献