共查询到20条相似文献，搜索用时 31 毫秒
1.
A rigorous theoretical investigation on the characteristics of dust-ion-acoustic (DIA) shock waves in an unmagnetized multi component electron-positron-ion dusty plasma (consisting of inertial ions, electrons of two distinct temperatures referred to as low and high temperature superthermal electrons where superthermality is introduced via the κ-type of nonthermal distribution, Boltzmann distributed positrons, and negatively charged immobile dust grains) has been made both theoretically and analytically. The hydrodynamic equation for inertial ions has been used to derive the Burgers equation. The influence of superthermal electrons, Maxwellian positrons and ion kinematic viscosity, which are found in this investigation, significantly modify the basic features of DIA shock waves, are briefly discussed. The present investigation can be very effective for studying and understanding the basic characteristics of shock wave propagation through different astrophysical situations where distinct temperature superthermal electrons dominate the wave dynamics. 相似文献
2.
Biswajit Sahu 《Astrophysics and Space Science》2012,338(2):251-257
The nonlinear wave structures of ion acoustic waves (IAWs) in an unmagnetized plasma consisting of nonextensive electrons
and thermal positrons are studied in bounded nonplanar geometry. Using reductive perturbation technique we have derived cylindrical
and spherical Korteweg-de Vries-Burgers’ (KdVB) equations for IAWs. The presence of nonextensive q-distributed electrons is shown to influence the solitary and shock waves. Furthermore, in the existence of ion kinematic
viscosity, the shock wave structure appears. Also, the effects of nonextensivity of electrons, ion kinematic viscosities,
positron concentration on the properties of ion acoustic shock waves (IASWs) are discussed in nonplanar geometry. It is found
that both compressive and rarefactive type solitons or shock waves are obtained depending on the plasma parameter. 相似文献
3.
Two dimensional ion acoustic shocks in electron-positron-ion (e-p-i) plasma with warm ions, and nonthermal electrons and positrons following the q-nonextensive velocity distribution are studied in the presence of weak transverse perturbations. The kinematic viscosity of warm ions is included for the dissipation in the plasma system. Kadomtsev–Petviashvili–Burgers (KPB) equation is derived by using reductive perturbation method in small amplitude limit and its analytical solution is also presented. The effects of variations of positrons concentration, q-indices of electrons and positrons, ion temperature and kinematic viscosity of ions, on the propagation characteristic of two dimensional shock profile are also discussed. 相似文献
4.
M. Mehdipoor 《Astrophysics and Space Science》2012,338(1):73-79
Korteweg-de-Vries-Burger (K-dVB) equation is derived for ion acoustic shock waves in electron-positron-ion plasmas. Electrons
and positrons are considered superthermal and are effectively modeled by a kappa distribution in which ions are as cold fluid.
The analytical traveling wave solutions of the K-dVB equation investigated, through the (G′/G)-expansion method. These traveling wave solutions are expressed by hyperbolic function, trigonometric functions are rational
functions. When the parameters are taken special values, the shock waves are derived from the traveling waves. It is observed
that the amplitude ion acoustic shock waves increase as spectral index κ and kinematic viscosity η
i,0 increases in which with increasing positron density β and electron temperature σ the shock amplitude decreases. Also, numerically the effect different parameters on the nonlinearity A and dispersive B terms and wave velocity V investigated. 相似文献
5.
Properties of three-dimensional ion-acoustic solitary and shock waves accompining electron-positron-ion magnetoplasma with
high-energy (superthermal) electrons and positrons are investigated. For this purpose, a Zakharov-Kuznetsov-Burgers (ZKB)
equation is derived from the ion continuity equation, ion momentum equation with kinematic viscosity among ions fluid, electrons,
and positrons having kappa distribution together with the Poisson equation. The dependence of the solitary and shock excitations
characteristics on the parameter measuring the superthermality κ, the ion gyrofrequency Ω, the unperturbed positrons-to-ions density ratio ν, the viscosity parameter η, the direction cosine ℓ, the ion-to-electron temperature ratio σ
i
, and the electron-to-positron temperature ratio σ
p
have been investigated. Moreover, it is found that the parameters κ, Ω, ν, η, and ℓ lead to accelerate the particles, whereas the parameters σ
i
and σ
p
would lead to decelerate them. Numerical calculations reveal that the nonlinear pulses polarity are always positive. This
study could be useful to understand the nonlinear electrostatic excitations in interstellar medium. 相似文献
6.
Prasanta Chatterjee Deb Kumar Ghosh Biswajit Sahu 《Astrophysics and Space Science》2012,339(2):261-267
The nonlinear propagation of ion acoustic shock waves (IASWs) are studied in an unmagnetized plasma consisting of nonthermal
electrons, nonthermal positrons, and singly charged adiabatically hot positive ions, whose dynamics is governed by the two
dimensional nonplanar Kadomstev-Petviashvili-Burgers (KPB) equation. The shock solution of the KPB equations is obtained numerically.
The effects of several parameters and ion kinematic viscosities on the properties of ion acoustic shock waves are discussed
in planar and nonplanar geometry. It is shown that the ion acoustic shock wave propagating in cylindrical/spherical geometry
with transverse perturbation will be deformed as time goes on. Also, it is seen that the strength and the steepness of the
IASWs increases with increasing β, the nonthermal parameter. 相似文献
7.
Hamid Reza Pakzad 《Astrophysics and Space Science》2011,334(1):55-60
Ion acoustic shock waves (IASWs) are studied in a plasma consisting of nonextensive electrons and ions. The dissipation is
taken into account the kinematic viscosity among the plasma constituents. The Korteweg-de Vries-Burgers (KdV-Burgers) equation
is derived by reductive perturbation method. Shock waves are solutions of KdV-Burgers equation. It is shown that acceptable
values of q-parameter (where q stands for the electron nonextensive parameter) are more than 3 in a weakly nonlinear analysis. We have found that the amplitude
of shock waves decreases by an increasing q-parameter. 相似文献
8.
Hamid Reza Pakzad Kurosh Javidan Mouloud Tribeche 《Astrophysics and Space Science》2014,352(1):185-191
The propagation of cylindrical and spherical electron acoustic (EA) shock waves in unmagnetized plasmas consisting of cold fluid electrons, hot electrons obeying a superthermal distribution and stationary ions, has been investigated. The standard reductive perturbation method (RPM) has been employed to derive the cylindrical/spherical Korteweg-de-Vries-Burger (KdVB) equation which governs the dynamics of the EA shock structures. The effects of nonplanar geometry, plasma kinematic viscosity and electron suprathermality on the temporal evolution of the cylindrical and spherical EA shock waves are numerically examined. 相似文献
9.
A weakly nonlinear analysis is carried out to derive a Korteweg–de Vries-Burgers-like equation for small, but finite amplitude,
ion-acoustic waves in a dissipative plasma consisting of weakly relativistic ions, thermal positrons and nonextensive electrons.
The travelling wave solution has been acquired by employing the tangent hyperbolic method. Our results show that in a such
plasma, ion-acoustic shock waves, the strength and steepness of which are significantly modified by relativistic, nonextensive
and dissipative effects, may exist. Interestingly, we found that because of ion kinematic viscosity, an initial solitonic
profile develops into a shock wave. This later evolves towards a monotonic profile (dissipation-dominant case) as the electrons
deviate from their Maxwellian equilibrium. Our investigation may help to understand the dissipative structures that may occur
in high-energy astrophysical plasmas. 相似文献
10.
Nonlinear cylindrical fast magnetoacoustic waves are investigated in a dissipative magnetoplasma comprising of electrons,
positrons, and ions. In this regard, cylindrical Kadomtsev-Petviashvili-Burgers (CKPB) equation is derived using the small
amplitude perturbation expansion method. Furthermore, cylindrical Burgers-Kadomtsev-Petviashvili (Cyl Burgers-KP) for a fast
magnetoacoustic wave is derived, for the first time, for spatial scales larger than the electron/positron skin depths, c/ω
p(e,p). Using the tangent hyperbolic method, the solutions of both planar KPB and Burgers-KP equations are obtained and then subsequently
used as an initial profile to solve their respective counterparts in the cylindrical geometry. The effect of positron concentration,
kinematic viscosity, and plasma β are explored both for the KPB and the Burgers-KP shock waves and the differences between the two are highlighted. The temporal
evolution of the cylindrical fast magnetoacoustic wave is also numerically investigated. The present study may be beneficial
to study the propagation characteristics of nonlinear electromagnetic shock waves in planetary magnetospheres. 相似文献
11.
The nonlinear propagation of ion-acoustic solitary and shock waves in a dissipative, nonplanar quantum plasma comprised of electrons, positrons, and ions are studied. A modified Korteweg-de Vries Burgers equation is derived in the limit of low frequency and long wavelength by taking into account the kinematic viscosity among the plasma constituents. It is shown that this plasma system supports the propagation of both compressive and rarefactive nonlinear waves. The effects of variation of various plasma parameters on the time evolution of nonplanar solitary waves, the profile of shock waves, and the nonlinear structure induced by the collision of solitary waves are discussed. It is found that these parameters have significant effects on the properties of nonlinear waves in cylindrical and spherical geometries, and these effects for compressive and rarefactive nonlinear waves are obviously different. 相似文献
12.
Detection of ionospheric perturbation due to a soft gamma ray repeater SGR J1550-5418 by very low frequency radio waves 总被引：1，自引：0，他引：1
Sushanta K. Mondal Sandip K. Chakrabarti Sudipta Sasmal 《Astrophysics and Space Science》2012,338(2):259-264
The properties of cylindrical and spherical dust acoustic (DA) solitary and shock waves in an unmagnetized electron depleted
dusty plasma consisting of inertial dust fluid and ions featuring Tsallis statistics are investigated by employing the reductive
perturbation technique. A Korteweg-de Vries Burgers (KdVB) equation is derived and its numerical solution is obtained. The
effects of ion nonextensivity and dust kinematic viscosity on the basic features of DA solitary and shock waves are discussed
in nonplanar geometry. It is found that nonextensive nonplanar DA waves behave quite differently from their one-dimensional
planar counterpart. 相似文献
13.
A parametric survey on the propagation characteristics of the dust ion-acoustic (DIA) shock waves showing the effect of nonextesivity with nonextensive electrons in a dissipative dusty plasma system has been carried out using the reductive perturbation technique. We have considered continuity and momentum equations for inertial ions, q-distributed nonextensive electrons, and stationary charged dust grains, to derive the Burgers equation. It has been found that the basic features of DIA shock waves are significantly modified by the effects of electron nonextensivity and ion kinematic viscosity. Depending on the degree of nonextensivity of electrons, the dust ion-acoustic shock structures exhibit compression and rarefaction. The implications of our results would be useful to understand some astrophysical and cosmological scenarios like stellar polytropes, hadronic matter and quark-gluon plasma, protoneutron stars, dark-matter halos, etc., where effects of nonextensivity can play the significant roles. 相似文献
14.
Properties of fully nonlinear electron-acoustic solitary waves in an unmagnetized and collisionless electron-positron-ion plasma containing cold dynamical electrons, superthermal electrons and positrons obeying Cairns’ distribution have been analyzed in the stationary background of massive positive ions. A linear dispersion relation has been derived, from which it is found that even in the absence of superthermal electrons, the superthermal positron component can provide the restoring force to the cold inertial electrons to excite electron-acoustic waves. Moreover, superthermal electron and positron populations seem to enhance the electron acoustic wave phase speed. For nonlinear analysis, Korteweg-de Vries equation is obtained using the reductive perturbation technique. It is found that in the presence of positron both hump and dip type solitons appear to excite. The present work may be employed to explore and to understand the formation of electron acoustic soliton structures in the space and laboratory plasmas with nonthermal electrons and positrons. 相似文献
15.
S. A. El-Wakil Essam M. Abulwafa E. K. El-Shewy Abeer A. Mahmoud 《Astrophysics and Space Science》2013,346(2):383-393
The reductive perturbation method has been used to derive the Burgers equation for dust acoustic shock waves in unmagnetized plasma having electrons, singly charged ions, hot and cold dust species with Boltzmann distributions for electrons and ions in the presence of the cold (hot) dust viscosity coefficients. The time-fractional Burgers equation is formulated using Euler-Lagrange variational technique and is solved using the variational-iteration method. The effect of time fractional parameter on the behavior of the shock waves in the dusty plasma has been investigated. 相似文献
16.
Interaction of nonplanar ion acoustic solitary waves is an important source of information to study the nature and characteristics of ion acoustic solitary waves (IASWs) structures. The head-on collision between two cylindrical/spherical IASWs in un-magnetized plasmas comprising with inertial ions, superthermal electrons and positrons is investigated by using the extended version of Poincaré-Lighthill-Kuo (PLK) perturbation method. It has been shown numerically that how the interactions are taking place in cylindrical and spherical geometry. The nonplanar geometry modified analytical phase shifts following the head-on collision are derived. The effects of the superthermal electrons and positrons on the phase shift are studied. It is shown that the properties of the interaction IASWs in different geometry are very different. 相似文献
17.
Kurosh Javidan 《Astrophysics and Space Science》2013,343(2):667-673
Propagation of cylindrical and spherical ion acoustic solitary waves in plasmas consisting of cold ions, superthermal electrons and thermal positrons are investigated. It is shown that cylindrical/spherical Korteweg-de-Vries equation governs the dynamics of ion-acoustic solitons. The effects of nonplanar geometry and also superthermal electrons on the characteristics of solitary wave structures are studied using numerical simulations. Obtained results are compared with the results of the other published papers and errors in the results of some papers are pointed. 相似文献
18.
S. A. El-Tantawy N. A. El-Bedwehy S. Khan S. Ali W. M. Moslem 《Astrophysics and Space Science》2012,342(2):425-432
Arbitrary amplitude ion-acoustic solitary waves propagating in a magnetized plasma composed of positive ions, superthermal electrons and positrons are investigated. For this purpose, the ions are represented by the hydrodynamical fluid equations while the non-Maxwellian electrons and positrons densities are assumed to follow kappa (κ) distribution. The basic equations are reduced to a pseudoenergy-balance equation. Existence conditions for large amplitude solitary waves are presented. The analytical and numerical analysis of the latter show that the ion-acoustic solitary wave can propagate only in the subsonic region in our plasma system and it is significantly influenced by the plasma parameters. The present analysis could be helpful for understanding the nonlinear ion-acoustic solitary waves propagating in interstellar medium and pulsar wind, which contain an excess of superthermal particles. 相似文献
19.
Propagation of ion acoustic solitary waves are studied in e-p-i plasmas containing high relativistic ions, Maxwell–Boltzmann
distributed positrons and nonthermal electrons. Reductive perturbation method is used and the Korteweg-de Vries (KdV) equation
is derived. The effects of high relativistic ions and nonthermal electrons on soliton characters are studied. 相似文献
20.
A theoretical model is presented to investigate the existence, formation, and possible realization of nonlinear envelope ion acoustic solitary waves which accompany collisionless electron-positron-ion plasmas with high-energy electrons and positrons (represented by kappa distribution). By employing the reductive perturbation method, the hydrodynamic model and the Poisson equation are reduced to nonlinear Schr?dinger equation. The effects of the superthermal parameters, as well as ion-to-electron temperature ratio on the propagation and stability of the envelope solitary waves are examined. The superthermal parameters (ion-to-electron temperature ratio) give rise to instability (stability) of the solitary excitations, since the instability window is strongly modified. Finally, the present results should elucidate the excitation of the nonlinear ion-acoustic solitary wave packets in superthermal electron-positron-ion plasmas, particularly in interstellar medium. 相似文献