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1.
The general Schrödinger equation (GSE) for whistler waves with their group velocity directed along an external magnetic field is derived. The “mean” wave vector of the wave beam may be parallel to or have an angle Θ = arccos(2ω/ωc) with the magnetic field. Applications of GSE to the whistler propagation in density ducts are considered. The results are important for the problem of the self-focusing of whistler waves.  相似文献   

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An investigation is made of the self-interaction of whistler waves (whistlers) involving the formation of waveguide channels in a collisional magnetoactive plasma as a result of its additional ionization by the field of the propagating wave. Simplified equations are derived to describe the behavior of the whistler field in a channel of enhanced plasma density in the presence of electron collisions. Self-consistent distributions of the field and the plasma corresponding to steady-state ionization self-channeling of whistlers are obtained by numerically solving the equations for the field together with balance equations for the electron density and energy. Our estimates indicate that this effect can be observed under laboratory conditions. Zh. éksp. Teor. Fiz. 112, 1285–1298 (October 1997)  相似文献   

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A gyrating ion beam, with a ring-shaped distribution in velocity, supports negative energy beam modes near the harmonics of beam gyro-frequency. An investigation of the non-linear interaction of high-frequency whistler waves with the negative energy beam cyclotron mode is made. A non-linear dispersion relation is derived for the coupled modes. It is shown that a gyrating ion-beam frequency upconverts the whistler waves separated by harmonics of beam gyro-frequency. The expression for the growth rate of whistler mode waves has been derived. In Case 1, a high-amplitude whistler wave decays into two lower frequency waves, called a low-frequency mode and a side band of frequency lower than that of pump wave. In Case 2 a high-amplitude whistler wave decays into two lower frequency daughter waves, called the low-frequency mode and whistler waves. Generation mechanism of these waves has application in space and laboratory plasmas.  相似文献   

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The electromagnetic plasma wave spectrum of an inversion layer plasma subject to Landau quantization is investigated here. Magnetic field effects on local and nonlocal plasma modes are determined using the two dimensional RPA magnetoconductivity tensor.  相似文献   

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The effect of a spatially-uniform periodic magnetic field on waves propagating perpendicular to it in a cold plasma is considered. Assuming that the pump field is weak, the method of multiple time scales is used to treat the problem. The results show that, unlike the pump electric field, the pump magnetic field does not produce any parametric excitation of the transverse waves, no matter what the value of the frequency mismatch is.  相似文献   

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Based on a numerical analysis of the dispersion relation for a hot magnetoplasma, we study the spectra of weakly damped high-frequency waves propagating in such a plasma in the case where the electron cyclotron frequency is higher than or equal to the plasma frequency. It is shown that with increasing magnetic field, the branches of the ordinary and slow extraordinary waves approach each other and become almost identical in wide ranges of frequencies and angles. A branch of waves with anomalous dispersion can appear if the angles between the wave vector and the magnetic field are close to 90°. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 2, pp. 136–141, February 2008.  相似文献   

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Summary An analytic solution is found for the evolution of the state of polarization of an electromagnetic wave propagating in a plasma with uniformly sheared magnetic field. It is the generalization of the one found previously for the special case of propagation perpendicular to the magnetic field.  相似文献   

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We study exact solutions to the Schrödinger equation with nonstationary potential in the form of a rectangular well with constant depth and linearly growing transverse dimension. We consider one dimensional systems and spherically symmetric systems.  相似文献   

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We investigate the influence of density ducts on the radiation of given sources in a magnetoplasma. We obtain the full-wave solution for the problem of radiation from annular electric and magnetic currents in the presence of a plasma column (density duct) oriented along an external magnetic field and surrounded by a uniform background magnetoplasma. Both the discrete part of the spatial spectrum of excited waves and the continuous part of the spectrum are considered. We calculate the total radiated power and partial powers radiated in separate eigenmodes guided by the column. It is established that in the whistler frequency range the presence of a channel with enhanced plasma density can cause a considerable increase in the radiation power of annular sources. We give concrete estimations for the ionospheric conditions and compare these results with the results obtained previously for the case of a uniform magnetoplasma without density ducts.Nizhnii Novgorod University. Tranlated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 7, pp. 887–908, July, 1994.  相似文献   

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The effect of a weak stochastic magnetic field on circular polarized waves in a plasma is investigated. It is shown that the waves are damped. The damping coefficients in various cases of interest are evaluated.  相似文献   

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Propagation of circularly polarized waves along a spatially uniform but temporally fluctuating magnetic field is considered. It is shown that the coherent waves are damped. The results are compared with those for Krook's relaxation model.  相似文献   

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The effect of a longitudinal magnetic field on the linear wake fields excited by a relativistic electron bunch in a cold homogeneous plasma is considered. The obtained results prove that the presence of an external magnetic field leads to a dependence of the wake wavelength on the transverse coordinate, to a change in the wave amplitude with increasing distance from the bunch, and to the emergence of anharmonicity. It is found that a strong magnetic field reduces the wave amplitude significantly for narrow bunches and changes the amplitude insignificantly for broad bunches.  相似文献   

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