Parametric excitation of relativistic plasma oscillations by strong electromagnetic waves

Parametric interaction of strong waves ($\text{?=}\text{eE}{}_{\mathrm{<mtext>o</mtext>}}\text{m}{}_{\mathrm{<mtext>e</mtext>}}\text{cω}{}_{\mathrm{<mtext>o</mtext>}}\text{～ 1}$) with a cold, two-fluid (ion and electron) plasma is studied in the limits of high frequency (ω_o?ω_Le) and resonance (ω_o ≈ ω_Le). Unstable oscillations of both electrons and ions are found in the resonance limit.     

Surface waves on the relativistic quantum plasma half-space

We present a theoretical investigation on the propagation of surface waves on the relativistic quantum plasma half-space. The dispersion relations of surface plasmon polaritons (SPPs) and electrostatic surface waves containing relativistic quantum corrected terms are derived. Results show that the frequency of SPPs has a blue-shift, and surface Langmuir oscillations can propagate on the cold plasma half-space due to quantum effects. Numerical evaluation indicates that quantum effects to SPPs and electrostatic surface waves are significant and observable.     

Effect of relativistic elliptical beam modulation on excitation of surface plasma waves in a magnetized dusty plasma column with elliptical cross section

Abstract

The excitation of surface plasma waves due to the interaction of an elliptical relativistic density modulated electron beam with the magnetized dusty plasma column with elliptical cross-section has been studied. The dispersion relation of surface plasma waves has been retrieved from the derived dispersion relation by considering that the beam is absent and there is no dust in the plasma elliptical cylinder. It is shown that the Cherenkov and fast cyclotron interactions appear between the beam and eigen-modes of plasma column. The growth rate of the instability increases with the beam density and modulation index as one-third power of the beam density in Cherenkov interaction and is proportional to the square root of beam density in fast cyclotron interaction. The numerical results and graphs are presented, too.     

Quantum ion-acoustic solitary waves in weak relativistic plasma

Small amplitude quantum ion-acoustic solitary waves are studied in an unmagnetized two- species relativistic quantum plasma system, comprised of electrons and ions. The one-dimensional quantum hydrodynamic model (QHD) is used to obtain a deformed Korteweg–de Vries (dKdV) equation by reductive perturbation method. A linear dispersion relation is also obtained taking into account the relativistic effect. The properties of quantum ion-acoustic solitary waves, obtained from the deformed KdV equation, are studied taking into account the quantum mechanical effects in the weak relativistic limit. It is found that relativistic effects significantly modify the properties of quantum ion-acoustic waves. Also the effect of the quantum parameter H on the nature of solitary wave solutions is studied in some detail.     

Surface waves at the boundaries of relativistic plasma streams

A study is made of stable and unstable electromagnetic surface waves at the boundaries of the plane and cylindrical relativistic plasma streams in the frequency range corresponding to positive values of the plasma permittivity. It is demonstrated that there are critical parameters for the transition from slow to fast waves, namely, the angle between the velocity and the wave vector in plane geometry and the smallest mode number in cylindrical geometry. It is shown that the critical parameter for the onset of the firehose instability of an electron stream is the transverse size of the stream. Higher firehose modes of the stream are shown to be suppressed by applying a strong longitudinal magnetic field.     

Parametric excitation of Langmuir oscillations in a relativistic electron plasma

A systematic discussion is carried out of the parametric action of an external high-frequency field on a high-temperature plasma. The conditions for the onset of parametric resonance and the corresponding increments, as well as the frequency shift of the Langmuir oscillations under the action of a high-frequency field, are found.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 58–61, May, 1982.     

Speed and shape of solitary waves in relativistic warm plasma

Large-amplitude solitary waves are investigated in a relativistic plasma with finite ion-temperature. The mass of electron is also considered. The Sagdeev’s pseudopotential is determined in terms ofu, the ion speed. It is found that there exists a critical value ofu ₀, the value ofu at which (u′)²=0, beyond which the solitary waves cease to exist. The critical value also depends on the parameters likeν, the soliton velocity;μ, the electronion mass ratio orσ, the temperature ratio of ion to electron. This result reproduces our previous result [Czech. J. Phys., Vol. 54 (2004), No. 4, 489–496] when the ion temperature is neglected.     

Nonlinear scattering of longitudinal waves in a weakly turbulent relativistic plasma

Nonlinear scattering of Langmuir waves of small amplitude in an isotropic relativistic Maxwellian plasma is investigated. The coefficient of nonlinear scattering of waves in a relativistic plasma is calculated, and the weak relativistic and ultrarelativistic asymptotes of the expression obtained for this coefficient in the long-wave approximation are also found.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 53–56, February, 1982.     

X-ray surface waves generated by the resonant coherent excitation of relativistic ions in crystals

X-ray ion radiation, caused by resonant coherent excitation (RCE) in a crystal, arises at the crystal-vacuum interface and propagates along the surface, generating a so-called surface wave. The dependence between the surface-wave intensity and the departure angle of characteristic X-ray radiation upon RCE is investigated in a kinematic approximation of diffraction theory. It has been shown that the angular dependence for the intensity of this radiation leaving the crystal surface differs substantially from the radiation intensity inherent to the decay of ion states excited by RCE.     

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.     

Ultrarelativistic excitation of beat waves in a hot magnetized plasma

Summary A theoretical investigation is made on the nonlinear relativistic excitation of an electrostatic electron plasma wave at the beat frequency of two high-power colinear laser beams in a hot, homogeneous and magnetized plasma. The relativistic Vlasov equation expressed in gyrokinetic variables has been employed to find the nonlinear response of the magnetized plasma electrons. It is noted that the power density associated with the excited beat wave is much higher for the relativistic consideration than that for the nonrelativistic consideration. The authors of this paper have agreed to not receive the proofs for correction.     

Ion-acoustic waves in a relativistic plasma for various particle velocity distributions

It is established that longitudinal ion-acoustic modes can exist only in the one-dimensional case in a relativistic plasma with an arbitrary particle velocity distribution. The spectrum of the given wave mode is calculated on the basis of Vlasov's kinetic theory for an arbitrary particle velocity distribution function. In particular, the dispersion and logarithmic decrement are found for power-law and Maxwell distribution functions.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 103–107, March, 1995.