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1.
Summary In this paper the relativistic second-harmonic generation of a high-power laser radiation in a laser-produced plasma has been
studied theoretically in the presence of a self-generated magnetic field. The relativistic Vlasov equation has been employed
for the nonlinear response of the electrons in the hot magnetized plasma. It is observed that the power conversion efficiency
of the generated second harmonic wave is much higher for relativistic calculations than that for nonrelativistic calculations.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献
2.
Properties of nonlinear electrostatic solitary waves in a magnetized multicomponent system of plasma containing of warm fluid ions, weakly relativistic warm fluid electrons and q-nonextensive distributed electrons using reductive perturbation method, have been surveyed. For this purpose, a KdV soliton type solution has been employed. The dependence of solitary wave structure, solitary wave maximum amplitude, and phase velocity of soliton on the plasma parameters is defined numerically. 相似文献
3.
In this paper we have theoretically investigated the quantum and relativistic effects on ion plasma wave in an unmagnetised dust-ion plasma. By using the method of normal mode analysis, we have obtained a linear dispersion relation. It has been analysed numerically for quantum and relativistic effects on the propagation of ion plasma wave. By using the standard reductive perturbation technique, we have derived a Korteweg–de Vries (KdV) equation which describes the nonlinear propagation of the wave. Numerically, it is shown that only compressive type of soliton can exist in the plasma under consideration. It is found that the solitary wave profile depends significantly on the quantum and relativistic parameters. The dust size, dust charge and the dust number density are also shown to have significant influences on these solitary waves. The results of this present investigation have some relevance to the nonlinear propagation of ion plasma wave in some astrophysical, space and laboratory plasma environments. 相似文献
4.
Nonlinear Dynamics of Circularly Polarized Laser Pulse Propagating in a Magnetized Plasma with q ‐Nonextensive Velocity Distributions 下载免费PDF全文
The nonlinear dynamics of a circularly polarized laser pulse propagating in magnetized plasma contains hot nonextensive q ‐distributed electrons and ions is studied theoretically. A nonlinear equation which describes the dynamics of the slowly varying amplitude electromagnetic wave is obtained using the relativistic two‐fluids model. Some nonlinear phenomena include modulational instability, self‐focusing, soliton formation, and longitudinal and transversal evolutions of laser pulse in nonextensive plasma medium are investigated. Results show that the nonextensivity of particles can substantially change the nonlinearity of medium. The external magnetic field enhances the modulation instability growth rate of right‐hand polarization wave but for the left‐hand polarization the growth rate decreases. The spot size of the laser pulse is strongly affected by the plasma nonextensivity. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
5.
Modulation instability of an intense right-hand elliptically polarized laser beam propagating through magnetized plasma is investigated by a new method. The nonlinear dispersion relation, in which the relativistic and ponderomotive nonlinearities are taken into account, is obtained for the laser radiation in magnetized plasma by the Lorentz transformation. The Karpman equation is firstly generalized to the case of three dimensions with three field components. When the nonlinear frequency shift of the electromagnetic field in plasma is involved, the nonlinear evolution equation for the slowly varying envelope of the laser field is obtained. Thus, modulation instability of the intense laser beam in magnetized plasma is studied and the temporal growth rate of the instability is derived. The analysis shows that the peak growth rate of self-modulation instability is increased due to the axial magnetization of plasma. It is also shown that the growth rate of modulation instability is increased significantly near the critical surface in a laser-plasma. 相似文献
6.
Lai C.H. Katsouleas T.C. Mori W.B. Whittum D. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1993,21(1):45-52
The interaction of a light wave with a relativistic ionization front in the presence of an applied DC magnetic field which is perpendicular or parallel to the incident wave is considered. In both cases, four transmitted modes are generated in the magnetized plasma by an incident linearly polarized wave. The frequency upshifts of the various modes are calculated and compared to the unmagnetized case. The corresponding reflection and transmission coefficients are also obtained. Finally, the density ripple associated with the free streaming mode in a magnetized plasma for the perpendicular case is discussed 相似文献
7.
8.
Two‐dimensional (2D) magnetosonic wave propagation in magnetized quantum dissipative plasmas is studied. The plasma system is comprised of inertial ions, inertia‐less electrons, and positrons. The multi‐fluid quantum hydrodynamic model is used, in which quantum statistical and quantum tunnelling effects of electrons and positrons are included. Reductive perturbation analysis is performed to derive the Zabolotskaya–Khokhlov equation for the 2D propagation of a magnetosonic shock wave in a magnetized qauntum plasma. The effects of varying the different plasma parameters such as positron density and magnetic field intensity on the propagation characteristics of magnetosonic shock waves are discussed with non‐relativistic degenerate plasma parameters in astrophysical plasma situations. 相似文献
9.
10.
S. Mahmood N. Akhtar 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(2):217-222
Linear and nonlinear ion acoustic waves in the presence of adiabatically heated ions in magnetized electron-positron-ion plasmas
are studied. The Sagdeev potential approach is employed to obtain the energy integral equation in such a mulitcomponent plasma
using fluid theory. It is found that electron density humps are formed in the subsonic region in magnetized electron-positron-ion
plasmas. The amplitude of electron density hump is decreased with the increase of hot ion temperature in electron-positron-ion
plasmas. However, the increase in positron concentration and obliqueness of the wave increases the amplitude of nonlinear
structure. The increase in positron concentration also reduces the width of the nonlinear structure in a magnetized multicomponent
plasma. The numerical solutions in the form of solitary pulses are also presented for different plasma cases. The results
may be applicable to astrophysical plasma situations, where magnetized electron-positron-ion plasma with hot ions can exist. 相似文献
11.
Shahzad Mahmood Hafeez Ur-Rehman Sajjad Hussain Muhammad Adnan 《Physics letters. A》2019,383(26):125840
The nonlinear ion-acoustic wave excitation and its stability analysis are investigated in a magnetized quantum plasma with exchange-correlation and Bohm diffraction effects of degenerate electrons in the model. Using reductive perturbation technique, the Zakharov-Kuznetsov (ZK) equation is derived for two dimensional propagation of ion-acoustic wave in a magnetized quantum plasma. It is found that the phase speed, amplitude and width of the nonlinear ion-acoustic wave structures are affected in the presence of exchange-correlation potential in the model. The stability analysis of the 2D ion-acoustic wave pulse is also presented. It is found that growth rate of the first and second order instabilities of 2D ion acoustic wave soliton is enhanced with the inclusion of exchange-correlation potential effect in the model. 相似文献
12.
Bao-Liang Qian 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(6):1578-1581
An exact solution is found for the relativistic equation of motion of a charged particle driven by a circularly polarized electromagnetic wave and a constant magnetic field. The explicit expressions of particle position and velocity are obtained for certain initial conditions. The results are of interest to the interaction of the high-power laser with the magnetized plasma, electromagnetically pumped free-electron laser with a guide magnetic field, propagation of electromagnetic wave signals through a re-entry plasma sheath in the presence of a strong magnetic field, and magnetic confinement plasmas 相似文献
13.
《Physics letters. A》1997,234(2):122-126
It is shown that an electrostatic electron plasma beat wave is efficiently unstable for a low-frequency and short-wave-length purely growing perturbation (ω, k), i.e. an oscillating two-stream instability in a transversely magnetized hot plasma. The nonlinear response of electrons and ions with strong finite Larmor radius effects has been obtained by solving the Vlasov equation expressed in the guiding-center coordinates. The effect of ion dynamics has been found to play a vital role around ω ∼ ωci, where ωci is the ion-cyclotron frequency. For typical plasma parameters, it is found that the maximum growth rate of the instability is about two orders higher when ion motion is taken into account in addition to the electron dynamics. 相似文献
14.
Relativistic effects on the linear and nonlinear properties of electron plasma waves are investigated using the one-dimensional quantum hydrodynamic (QHD) model for a two-component electron?Cion dense quantum plasma. Using standard perturbation technique, a nonlinear Schr?dinger equation (NLSE) containing both relativistic and quantum effects has been derived. This equation has been used to discuss the modulational instability of the wave. Through numerical calculations it is shown that relativistic effects significantly change the linear dispersion character of the wave. Unlike quantum effects, relativistic effects are shown to reduce the instability growth rate of electron plasma waves. 相似文献
15.
Summary A large-amplitude beat wave excited at the beat frequency of two copropagating laser beams is extremely unstable and suffers
strong three- and fourwave parametric instabilities with large growth rates. The relativistic effects are seen to be negligible
on both the decay and modulation instabilities. However, the growth rates of these instabilities are sensitive functions of
the plasma parameters.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
16.
Paul S.N. Kashyapi P.K. Chakraborty B. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1992,20(5):481-486
The nonlinear dispersion relation for an electromagnetic wave propagating through a cold, homogeneous magnetized rotating plasma is derived to investigate certain nonlinear effect for the case where only the Coriolis force part of the consequences of rotation is taken into account. Characteristics of variation of refractive indices with variation of the wave amplitude and rotational frequency are discussed. It is shown that the nonlinear effects considerably influence the propagation of waves in rotating plasmas 相似文献
17.
The process of beat excitation of electron plasma waves in a plasma containing a density ripple is studied theoretically, experimentally, and computationally. A simple theoretical model has been developed which, for modest experimental parameters, predicts a new beat wave saturation mechanism. This mechanism involves the excitation of a spectrum of secondary electrostatic modes which divert pump energy from the beat wave and can lead to saturation of the beat wave at an amplitude well below that expected for relativistic detuning. Experiments designed to study the coupled mode spectrum were performed. The measured properties of the electrostatic spectrum are in reasonable agreement with the theory. To bridge the gap between the idealized model and the experiment, computer simulations were performed for a variety of parameters. The results of the simulations are in excellent agreement with the theory at early times prior to the onset of purely kinetic effects. For later times the simulations exhibit qualitative behavior which is consistent with the experimental measurements. Under certain conditions the model predicts the thermal quenching of the mode coupling saturation mechanism. These predictions are also verified in the simulations. 相似文献
18.
Propagation properties of dust-electron-acoustic waves in weakly magnetized dusty nonthermal plasmas
The linear and nonlinear properties of dust-electron acoustic waves (DEAWs) propagating in magnetized, collisionless, dusty plasma system containing inertial cold electrons, Maxwellian hot electrons, nonthermal ions, and arbitrarily (positively or negatively) charged stationary dust are investigated. The reductive perturbation technique is employed to reduce the basic set of fluid equations to the modified Korteweg-de Vries equation or Ostrovsky's equation, which governs the dynamics of small amplitude DEAWs in a weakly magnetized dusty nonthermal plasma. The approximate analytical as well as numerical solutions reveal that the basic characteristics of DEA nonlinear structures are found to be significantly modified by the key plasma configuration parameters. It is found that the leading compressive or rarefactive solitary wave structure separates from a trailing wave packet during a considerable time under the influence of magnetic field-induced Lorentz force. 相似文献
19.
Summary This paper presents a rigorous theoretical investigation of the relativistic and nonrelativistic modulational instability
of a high-power laser radiation propagating in a collisionless and unmagnetized laser-produced plasma. The kinetic equationviz. the relativistic Vlasov equation has been employed to find the nonlinear response of electrons for this four-wave parametric
process in the plasma. The actual motivation behind this theoretical investigation is to find the relativistic effect on this
four-wave paremetric processviz. the modulational instability. Here, it can be noted that the modulational instability of the laser radiation under our situation
has not a large but considerable relativistic effect and for the same set of plasma parameters the growth rate of the instability
in ultrarelativistic consideration is approximately three times higher than that in the nonrelativistic consideration.
The authors of this paper have agreed to not rective the proofs for correction. 相似文献
20.
E. Infeld 《Physics letters. A》1974,48(3):175-176
A class of nonlinear, small Mach number waves in a warm magnetized plasma is given. These waves are then investigated for ergodicity. These results that the wave is ergodic if a parameter, depending only on the Alfvén-Mach number for the wave, is irrational. 相似文献