非均匀量子等离子体中的非线性波

本文探讨具有温度和密度梯度的非均匀量子等离子体系统, 获得了该系统在离子与中子碰撞频率较低情况下的二维非线性流体动力学方程． 求得了非均匀量子等离子体中的电势的冲击、爆炸和旋涡解．分析讨论了在致密天体物理环境中静电势的变化, 结果表明电势的冲击波的幅度和爆炸波的宽度,都随密度的增大(即随无维量子参量的减小)而增大, 但随漂移速度的增大(即随密度和温度梯度的增大)而减小; 静电势随时空相位的增大而趋向于稳定值, 系统最后达到稳定的状态． 旋涡解表明,旋涡静电势的时空分布呈现稳定的周期性的旋涡流．     

Inertial Alfven waves in an inhomogeneous bi-Maxwellian plasma

The Vlasov kinetic equation is solved using gyrokinetic theory and the dielectric tensor for non-relativistic, magnetized, bi-Maxwellian plasmas is calculated. A generalized dispersion relation for kinetic Alfven waves is derived taking into account the density inhomogeneity and temperature anisotropy. The modified dispersion relation thus obtained is then used to examine the propagation characteristics of the kinetic Alfven waves in the inertial regime. The importance of density inhomogeneity and temperature anisotropy for Solar corona is highlighted. The growth rate of the inertial Alfven wave proves that density inhomogeneity acts as a source of free energy.     

Second-harmonic generation of electron-bernstein waves in an inhomogeneous plasma

In the injection of electron-Bernstein waves (EBW) into a plasma, proposed for plasma heating and current drive in over-dense plasma, conversion of the fundamental to its second harmonic is predicted analytically and observed in computations. The mechanism is traced to the existence of locations where one can have both wave number and frequency matching between the fundamental and its harmonic. Further, at such locations, the second harmonic commonly has minimal group velocity, and this allows the amplitude of the second harmonic to build to values exceeding that of the fundamental at power levels less than anticipated in experiments. The second-harmonic power can then be deposited at half-harmonic resonances of the original wave, often far from the desired location of energy deposition. Estimates for the power at which this is significant are given.     

Convective excitation of quasistatic waves in an inhomogeneous anisotropic plasma

Local as well as surface waves excited in a streamingless plasma are investigated. In addition to the gradient instabilities of an isothermal plasma now branches of a convective type are found in plasmas with a hot electron componentZ T _e T _i . Both their frequencies and growth rates may exceed the ion cyclotron frequency, > _Bi even if the effect of the finite ion Larmor radius is negligible. Then the surface waves may become of enhanced importance. We compare, therefore, the conditions for excitation and the growth rates of the surface waves with those of the short wavelength (local) perturbations. Upper estimates of the saturated wave amplitudes are also given. For a special profile of the plasma density the problem is solved analytically also in the plasma boundary layer.On leave of absence from the Physical and Technical Institute, Kharkov, U.S.S.R.     

Linear interaction of electromagnetic waves in an inhomogeneous magnetoactive plasma

In this paper we discuss an asymptotic method which permits one to separate the initial equations for the fields in a plane stratified plasma into two independent systems, describing waves of differing types which propagate in a single direction. The coefficients of the derived equations remain regular at points of equality between the indices of refraction of normal waves, n₁=n₂. The equations are used to analyze a specific type of interaction which is of current interest in connection with research on low-frequency waves in the ionosphere. A solution is found by the method of the standard system which describes the field in the interaction region; outside this region, it turns into the geometric optics solution. Wave transformation coefficients are compared with those obtained earlier by the phase integral method.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 21, No. 11, pp. 1563–1571, November, 1978.The author thanks N. G. Denisov for constant interest in this work and helpful discussions, and V. E. Belov and L. V. Rodygin for a valuable remark.     

Flow oscillations in radial expansion of an inhomogeneous plasma layer

The cylindrically symmetric radial evolution of an inhomogeneous plasma layer expanding into vacuum is investigated nonperturbatively by first determining the spatial structure of the plasma flow structure. The evolution is then governed by a set of ordinary differential equations. The effect of the plasma inhomogeneity on the nonlinear coupling among the electron and ion flow components and oscillations is investigated.     

Propagation and reflection of an electromagnetic wave in a hot inhomogeneous plasma

Using the WKB method a local dispersion equation of a right-hand circularly polarized wave and an expression for its electric field are derived, the wave having frequency smaller than the electron cyclotron frequency and propagating in a hot inhomogeneous plasma. The density gradient of the plasma is constant and parallel to an external magnetostatic field. Further the reflection coefficient of this wave is derived.Stimulating discussions with Dr. J. Václavík are gratefully acknowledged.     

Nonlinear interactions of surface waves with incident radiation at a narrow inhomogeneous plasma layer

The amplitudes of the waves radiating at combination frequencies from the plasma boundary due to nonlinear interaction of surface waves with radiation incident on a narrow inhomogeneous plasma layer, are determined. The method used allows for the discontinuity at the plasma boundary of the tangential components of the electric field of the wave at the combination frequencies.     

Dust-acoustic solitary waves in an adiabatic hot dusty plasma

An adiabatic hot dusty plasma (containing non-inertial adiabatic electron and ion fluids, and negatively charged inertial adiabatic dust fluid) is considered. The basic properties of arbitrary amplitude dust-acoustic (DA) solitary waves, which exist in such an adiabatic hot dusty plasma, are explicitly examined by the pseudo-potential approach. To compare the basic properties (critical Mach number, amplitude and width) of the DA solitary waves observed in a dusty plasma containing adiabatic electron, ion and dust fluids with those observed in a dusty plasma containing isothermal electron and ion fluids and adiabatic dust fluid, it has been found that the adiabatic effect of inertia-less electron and ion fluids has significantly modified the basic properties of the DA solitary waves, and that on the basic properties of the DA solitary waves, the adiabatic effect of electron and ion fluids is much more significant than that of the dust fluid.     

Double-Wronskian solitons and rogue waves for the inhomogeneous nonlinear Schrödinger equation in an inhomogeneous plasma

Plasmas are the main constituent of the Universe and the cause of a vast variety of astrophysical, space and terrestrial phenomena. The inhomogeneous nonlinear Schrödinger equation is hereby investigated, which describes the propagation of an electron plasma wave packet with a large wavelength and small amplitude in a medium with a parabolic density and constant interactional damping. By virtue of the double Wronskian identities, the equation is proved to possess the double-Wronskian soliton solutions. Analytic one- and two-soliton solutions are discussed. Amplitude and velocity of the soliton are related to the damping coefficient. Asymptotic analysis is applied for us to investigate the interaction between the two solitons. Overtaking interaction, head-on interaction and bound state of the two solitons are given. From the non-zero potential Lax pair, the first- and second-order rogue-wave solutions are constructed via a generalized Darboux transformation, and influence of the linear and parabolic density profiles on the background density and amplitude of the rogue wave is discussed.     

Cherenkov radiation waves in inhomogeneous dusty plasma

A kinetic theory is employed to study Cherenkov wave in an inhomogeneous dusty plasma. Two different frequency regimes are considered incorporating the plasma species temperatures. The dispersion relation for one-dimensional Cherenkov wave is derived and analyzed. The plasma species temperatures, their cyclotron frequencies, and the plasma density inhomogeneity effect the growth/damping of Cherenkov waves. It is shown that the plasma inhomogeneity contributes to damping of Cherenkov waves.