Top PDF Weakly Nonlinear Quantum Dust Ion Acoustic Waves

Weakly Nonlinear Quantum Dust Ion Acoustic Waves

Weakly Nonlinear Quantum Dust Ion Acoustic Waves

The one-dimensional quantum hydrodynamic (QHD) model for a three-specie quantum plasma is used to study the quantum counterpart of the well known dust ion-acoustic wave (DIAW). It is found that owing to the quantum effects, the dynamics of small but finite amplitude quantum dust ion-acoustic waves (QDIA) is governed by a deformed Korteweg-de Vries equation (dK-dV). The latter admits compressive as well as rarefactive stationary QDIA solitary wave solution. In the fully quantum case, the QDIA soliton experiences a spreading which becomes more significant as electron depletion is enhanced.
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Ion Acoustic Waves in a Unidirected Dusty Plasma

Ion Acoustic Waves in a Unidirected Dusty Plasma

Investigation of nonlinear phenomena in various media is the thrust area of research in science and technology. Many non-linear fascinating structures like solitary waves, double layers etc. are abundant in the complex space laboratory. Ion acoustic waves (IAW) with two and multi-component plasmas are being studied continuously for the last four decades. The emergence of relativistic and quantum effects in plasmas opens a new dimension in the studies of solitary waves. Further the occurrence of charged dust particles in space plasmas has created immense interest in the minds of plasma workers. Besides, insertion of dust particles (charged) into the laboratory plasma is found by the experimentalists to drastically change the properties of IA waves. A lot of investigation has already been completed in the last few decades to the studies of various properties of IA waves in plasmas without dust particles.
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Landau damping of dust acoustic solitary waves in nonthermal plasmas

Landau damping of dust acoustic solitary waves in nonthermal plasmas

Dust acoustic (DA) solitary and shock structures have been investigated under the influence of Landau damping in a dusty plasma containing two temperature nonthermal ions. Motivated by the observations of Geotail spacecraft that reported two-temperature ion population in the Earth’s magnetosphere, we have investigated the effect of resonant wave-particle interactions on DA nonlinear structures. The KdV equation with an additional Landau damping term is derived and its analytical solution is presented. The solution has the form of a soliton whose amplitude decreases with time. Further, we have illustrated the influence of Landau damping and nonthermality of the ions on DA shock structures by a numerical solution of the Landau damping modified KdV equation. The study of the time evolution of shock waves suggests that an initial shock-like pulse forms an oscillatory shock at later times due to the balance of nonlinearity, dispersion and disspation due to Landau damping. The findings of the present investigation may be useful in understanding the properties of nonlinear structures in the presence of Landau damping in dusty plasmas containing two temperature ions obeying nonthermal distribution such as in the Earth’s magnetotail.
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Effect of Electron and/or Ion Nonthermality on Dust Acoustic Wave Propagation in a Complex Plasma in Presence of Positively Charged Dust Grains Generated by Secondary Electron Emission Process

Effect of Electron and/or Ion Nonthermality on Dust Acoustic Wave Propagation in a Complex Plasma in Presence of Positively Charged Dust Grains Generated by Secondary Electron Emission Process

Theoretical investigations of nonthermal plasmas have been considerably important since early nineties. Mo- tivated by the observations of solitary structures with density depletions made by Freza and Viking satellites [13] [14] existence of both compressive and rarefactive solitary waves were theorically established for nonthermally distributed electrons and cold [15] [16] and warm ions [17]. Ion acoustic electrostatic solitary waves in unmag- netized nonthermal plasmas with inertial ion fluids and nonthermally distributed electrons were investigated by Mamun (2000) [18]. Tang and Xue (2004) [19] obtained nonlinear Schrodinger equation to study the instability of oblique modulation of finite amplitude ion-acoustic waves in an unmagnetized plasma consisting of warm adiabatic ions and nonthermal electrons. It was found that the presence of nonthermal electrons significantly changed the domain of modulational instability. Verheest et al. (2012) [20] have investigated the head on colli- sions of electrostatic solitons in nonthermal plasmas. All the above studies were performed in electron-ion plasmas in absence of dust. Kakati et al. (2011) [21] have shown that presence of dust grains in plasma changes the shape of the electron energy probability function (EEPF). From laboratory observation they have seen that the number of high energy electrons increases with respect to the number of mid energy range electrons in pres- ence of dust grains indicating that addition of dust grains efficiently thermalizes the plasma.
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Study of solitary waves in space plasmas

Study of solitary waves in space plasmas

Recently, there has been a great deal of interest in understanding different types of collective processes in dusty plasmas which are very common in laboratory an d astroph ysical environments. It has been found that the presence of static charged dust grains modifies the existing plasma wave spectra, whereas the dust charge dynamics introduces new eigenmodes in dusty plasmas. Rao et al. [90], for example, were the first to report theoretically the existence of extremely low phase velocity (in comparison with the electron and ion thermal velocities) dust-acoustic waves in an unmagnetised dusty plasma whose constituents are an inertial charged dust fluid and Boltzmann distributed electrons and ions. Thus, in the dust-acoustic waves the dust particle mass provides the inertia, whereas the restoring force comes from the pressures of inertialess electrons and ions. A recent laboratory experiment [96] has conclusively verified the theoretical prediction of Rao et al. [90] and has reported the nonlinear features of the dust-acoustic waves. The laboratory observations [96] of low phase velocity dust-acoustic waves, which are associated with significant depletion of the electron number density, suggest that the wave d ynamics is governed by the inertia of the dust fluid and the pressure of inertialess ions only. In this chapter.
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Effect of Positive Dust on Non linear Properties of Electron acoustic Waves

Effect of Positive Dust on Non linear Properties of Electron acoustic Waves

On the other hand, it is now well established that the presence of charged dust [16–18] does not only significantly modify the basic features of nonlinear ion-acoustic waves, but also introduces some new features, which are very important from both the theoretical and experimental points of view [19–23]. Recently, the nonlinear propagation of the ion-acoustic waves [24–30] in a plasma with charged dust, where the ion mass provides inertia, the electron thermal pressure gives rise to the restoring force, and the charged dust maintain the background charge neutrality condition, has been investigated. Since the eff ect of the dust charge fluctuation on any kind of low-frequency electrostatic waves (e.g. modified ion- acoustic waves, modified electron-acoustic waves, etc.), whose frequency is comparable to the dust charging frequency, is very important from both the theoretical and experimental points of view [16, 17, 23], in the present work we investigate the nonlinear propagation of a low phase speed (in comparison with the hot electron thermal speed) electrostatic perturbation mode in a dusty plasma containing cold and hot electrons, stationary and streaming ions, and charge fluctuating stationary dust. It is found here that the dust charge fluctuation is the source of dissipation, and is responsible for the formation of the dust- electron-acoustic shock waves in such a dusty plasma.
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Analysis of Nonlinear Dust Acoustic Shock Waves in an Unmagnetized Dusty Plasma with q Nonextensive Electrons Where Dust Is Arbitrarily Charged Fluid

Analysis of Nonlinear Dust Acoustic Shock Waves in an Unmagnetized Dusty Plasma with q Nonextensive Electrons Where Dust Is Arbitrarily Charged Fluid

The wave propagation in dusty plasmas has received much attention in the recent years because of its vital role in understanding different types of collective processes in space plasma environments, namely, lower and upper mesossphere, cometary tails, planetary rings, planetary magnetosphere, interplanetary spaces, interstellar media, etc. [1] [2]. The presence of charged dust grains in a plasma modifies the existing plasma wave spectra as well as introduces a number of novel eigen modes [viz. dust-ion acoustic (DIA) waves [3], dust-acoustic (DA) waves [4], dust lattice waves, etc.]. The dust grains acquire a negative charge by the collection of electrons [5] [6] be- cause the thermal speed of the electrons is much higher than that of the ions. On the other hand, dust grains may become positively charged also due to a variety of processes including photo-electron emission by UV photons, thermoionic emission induced by radiative heating [5] [7], secondary electron production, etc. However, Shah- mansouri and Tribeche have considered [8] the effects of arbitrary amplitude DA solitary waves in an unmagne-
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Time Dependent Nonplanar Dust Ion Acoustic Gardner Double Layers

Time Dependent Nonplanar Dust Ion Acoustic Gardner Double Layers

The nonlinear structures (viz., solitary waves, shock structure, and double layers) associated with the DIA waves have also received a great deal of interest because they have a great impact in understanding the basic pro- perties of the localized electrostatic perturbations not only in space [6-9], but also in laboratory dusty plasmas [10-14]. A number of investigations have been made on these nonlinear structures [6-12], particularly DIA soli- tary waves (SWs) [11,15-19], shock waves [12,13,20-24], and double layers (DLs) [25-28]. All of these work [11, 12,15-19] are confined in planar geometry. Since the waves observed in laboratory devices are certainly not bounded in one-dimension, the investigations made on 1D (planar) nonlinear DIA waves, may not be appropri- ate for realistic space or laboratory dusty plasma situa-
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Properties of Electron Ion Acoustic Solitary Waves in a Magnetized Degenerate  Quantum Plasma

Properties of Electron Ion Acoustic Solitary Waves in a Magnetized Degenerate Quantum Plasma

The nonlinear propagation of electron-ion (El) acoustic solitary waves in a degenerate quantum plasma (containing relativistic magnetized quantum electrons and light ions in presence of stationary heavy ions) have been theoretically investigated. The dV) equations are derived by adopting the reductive perturbation method. Their stationary solutions are derived and analyzed analytically as tures of the El acoustic solitary structures that are commonly found to exist in degenerate quantum plasma. It is found that the basic properties (viz. amplitude, width, and phase speed, etc.) of the El acoustic waves are significantly modified by the degenerate electrons and light ions, quantum pressure, number densities of plasma particles, and external magnetic field, etc. The results of this theoretical investigation may be tures of the solitary structures in astrophysical compact
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Dust Acoustic Solitary Waves in an Unmagnetized Dusty Plasma with Arbitrarily Charged Dust Fluid  and Trapped Ion Distribution

Dust Acoustic Solitary Waves in an Unmagnetized Dusty Plasma with Arbitrarily Charged Dust Fluid and Trapped Ion Distribution

The nonlinear propagation of dust-acoustic (DA) solitary waves in three-component unmagne- tized dusty plasma consisting of Maxwellian electrons, vortex-like (trapped) ions, and arbitrarily charged cold mobile dust grain has been investigated. It has been found that, owing to the depar- ture from the Maxwellian ions distribution to a vortex-like one, the dynamics of small but finite amplitude DA waves is governed by a nonlinear equation of modified Korteweg-de Vries (mK-dV) type instead of K-dV. The reductive perturbation method has been employed to study the basic features (phase speed, amplitude, width, etc.) of DA solitary waves which are significantly mod- ified by the presence of trapped ions. The implications of our results in space and laboratory plasmas are briefly discussed.
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Investigation of Dust-Ion Acoustic Waves in a Magnetized Collisional Dusty Plasma with Kappa Distribution Function for Electrons

Investigation of Dust-Ion Acoustic Waves in a Magnetized Collisional Dusty Plasma with Kappa Distribution Function for Electrons

Nowadays, the study of dusty plasmas properties has received a great deal of attention both theoretically and experimentally. In the presence of massive and highly charged dust particulates in an usual electron ion plasma new types of waves, such as dust acoustic (DA) waves and dust-ion- acoustic (DIA) waves are excited. These dusts can be regarded as static or mobile particles [1]. The nonlinear waves particularly, the DIA solitary waves (DIASW) have been theoretically investigated by several authors [2-6].
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Dust Acoustic (DA) Waves in a Magnetised Plasma with Boltzmann Distributed Electrons and Ions

Dust Acoustic (DA) Waves in a Magnetised Plasma with Boltzmann Distributed Electrons and Ions

investigated the ion-acoustic solitary wave in a relativistic plasma consisting of hot electrons and cold ions by Sagdeev pseudopotential method using a set of fully relativistic two-fluid equations. Very recently Kalita et al. [9] have investigated the existence of ion-acoustic relativistic solitons in an unmagnetised plasma with positive ion beam. In this investigation, they have considered lower and higher order relativistic effects. Recently Kalita and Deka (2013) [1] have investigated ion acoustic solitons in a weakly relavistic magnetised plasma based on initial steaming speeds in which the lower limit of the speed of light to characterise relativistic compressive solitons is predicted. Besides, Kalita and Choudhury (2013) [10] have also established the role of unidirected relativistic electrons with inertia in the formation of the weakly relativistic ion acoustic solitons in magnetised plasma. Both subsonic and supersonic compressive solitons are established. The generation of compressive solitons are shown to confine near the vicinity of the direction of the magnetic field in small subsonic range.
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Nonlinear Propagation of Dust Ion Acoustic Waves in a Degenerate Dense Plasma

Nonlinear Propagation of Dust Ion Acoustic Waves in a Degenerate Dense Plasma

explained by Chandrasekhar [4] for two limits, namely non-relativistic and ultra-relativistic limits. The inter- stellar compact objects provide us cosmic laboratories for studying the properties of the medium (matter), as well as waves and instabilities [9-22] in such a medium at extremely high densities (degenerate state) for which quantum as well as relativistic effects become important [9,21]. The quantum effects on linear [16,18,22] and nonlinear [17,20] propagation of electrostatic and elec- tromagnetic waves have been investigated by using the quantum hydrodynamic (QHD) model [9,21], which is an extension of classical fluid model in a plasma, and by using the quantum magneto-hydrodynamic (QMHD) model [16-20], which involve spin 1
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Ion Nonthermality Induced Nonlinear Dust Acoustic Wave Propagation in a Complex Plasma in Presence of Weak Secondary Electron Emission from Dust Grains

Ion Nonthermality Induced Nonlinear Dust Acoustic Wave Propagation in a Complex Plasma in Presence of Weak Secondary Electron Emission from Dust Grains

DOI: 10.4236/jmp.2018.95059 963 Journal of Modern Physics nonlinear theory of dust acoustic wave propagation considering the presence of nonthermal ions, Boltzmann distributed primary and secondary electrons and inertial dust grains having negative equilibrium dust charge. This negative equi- librium dust charge is a consequence of low secondary electron emission from dust grains. Study of this paper is important as we have seen [12] [13] opposite polarity of dust charge gives rise some opposite physical behaviour when the dust grains are charged by secondary electron mechanism. Thus to compare the nonlinear behaviour of dust acoustic waves with reference [11] where equilib- rium dust charge was positive we have considered both adiabatic (fast) and nonadiabatic (slow) dust charge variation.
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Properties of Electron Ion Acoustic Solitary Waves in a Four Component Degenerate Quantum Plasma

Properties of Electron Ion Acoustic Solitary Waves in a Four Component Degenerate Quantum Plasma

On the other hand, Ali et al. (2007) analyzed the IA waves in an EPI plasma, and found that the nonlinear properties of the IA waves are significantly affected by the inclusion of the quantum terms in the momentum equations of electrons and positrons. But none of them considered the effects of external magnetic field and the presence of the heavy ions. It is well known that (Miller, 1987; Plastino, 1993; Gervino, 2012) the presence of external magnetic field (which causes the obliqueness of the wave propagation) plays a vital role in modifying the basic features of the linear and nonlinear waves in space and astrophysical plasmas (Mahmood, 2008; Sultana, 2010; El-Tantawy, 2012; Shahmansouri, 2013; Alinejad, 2013; Ashraf et al., 2014), and that the most of astrophysical degenerate quantum plasma systems like white dwarfs and neutron stars usually contain degenerate electrons and light ions along with heavy ions (Koester, 1990). This means that the effects of heavy ions and magnetic field must be considered, specially for the study of the nonlinear phenomena in the degenerate astrophysical objects (Woolsey, 2004; Shapiro, 1983; Torres et al., 2010; Mamun, 2010). Obliquely propagating electron-acoustic (EA) solitary waves (SWs) in a two electron population quantum rnag-netoplasma was theoretically investigated by Masood and Mushtaq (2008). They found that propagation character- istics of the EA SWs are significantly affected by the presence of quantum corrections and the ratio of hot to cold electron concentration. Recently, Hossen and Mamun have theoretically investigated the nonlinear positron-acoustic (PA) waves propagating in the fully relativistic electron-positron-ion plasma and found that the effects of relativistic degeneracy of electrons and positrons, static heavy ions, plasma particles velocity, and enthalpy, etc. have significantly modified the basic
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Compressive and rarefactive dust-ion acoustic solitary waves in four components ‎quantum plasma with dust-charge variation

Compressive and rarefactive dust-ion acoustic solitary waves in four components ‎quantum plasma with dust-charge variation

As usual, the dust charge is a function of the plasma parameters, but as a consequence of that, the typical dust charging time scale may be longer than the DIA time scale, and we anticipate that the dust charge fluctuations have no essential effect on the DIA mode, and the dust charge can therefore be assumed to be constant. All of the works that mentioned in above satisfy this situation and in other words, dust charge assumed to be constant. However, in a realistic situation in space and laboratory devices the charge on a dust grain is not constant but varies with space and time [34]. Ghosh et al. [35-37] have studied nonlinear propagation of the DIA waves, particularly solitary [35] in a dusty plasma by taking into account the dust charge variation. Alinejad 2010 [38] investigated the one dimensional dynamics of nonlinear electrostatic dust ion-coustic (DIA) waves in an unmagnetized dusty plasma consisting of ion fluid, non- thermal electrons and fluctuating immobile dust particles has been made by the reductive perturbation technique. He found that the dust charge fluctuation is a source of dissipation, and is responsible for the formation of the dust ion-acoustic shock waves. To the best of our knowledge, no investigation for nonlinear DIA solitary waves in four component quantum plasma with consideration of dust charge variation has been made.
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Relativistic Degeneracy Effect on Propagation of Arbitrary Amplitude Ion-Acoustic Solitons in Thomas-Fermi Plasmas

Relativistic Degeneracy Effect on Propagation of Arbitrary Amplitude Ion-Acoustic Solitons in Thomas-Fermi Plasmas

Of the nonlinear excitations, ion-acoustic solitary waves (IASWs) are of the most important and well- understood characteristics of plasma environments. The- oretical studies of main properties of these solitary struc- tures date back to 1961 using Sagdeev pseud-potentials method [1]. Another method which is widely used to in- vestigate the collective wave phenomenon in plasma is the so-called multi-scales perturbation method [2–8]. How- ever, the latter method, which is based on approximation, is used only for the small-amplitude treatment of plasma in a state away from thermodynamic equilibrium. There- fore to obtain a good agreement with experiments, in this method, one needs to take higher-orders in perturbation amplitudes. In recent years there have been many inves- tigations on solitary IASWs as well as solitary electro- static waves (ESWs) in diverse plasma environments us- ing Sagdeev pseudo-potential approach [9–13]. The small amplitude propagation and interaction of IASWs with rela- tivistic degeneracy pressure effects have been recently con- sidered in Ref. [14].
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Effect of Dust Grain Parameters on Ion Beam Driven Ion Cyclotron Waves in a Magnetized Plasma

Effect of Dust Grain Parameters on Ion Beam Driven Ion Cyclotron Waves in a Magnetized Plasma

Abstract—Excitation of electrostatic ion cyclotron waves (EICW) in a magnetized dusty plasma by an ion beam is studied taking into account the effect of dust particle size, dust particle charge and dust particle number density variations. The presence of dust grain charge fluctuations modifies the dispersion relation for ion cyclotron waves in dusty plasma. It is shown that in the absence of ion beam, the ion cyclotron mode damps due to dust charge fluctuations and an additional damping dust charge fluctuation mode is induced in plasma. The ion beam propagating parallel to the magnetic field drives ion cyclotron waves to instability via Cerenkov interaction. Using the analytical and numerical results the influence of the relative density of negatively charged dust particles on growth rate of ion cyclotron waves is studied. The dust grain size distribution has also significant contributions on the growth rate of ion cyclotron waves.
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Time-delay estimation and correlation analysis of acoustic signals in granular media using wavelet decomposition

Time-delay estimation and correlation analysis of acoustic signals in granular media using wavelet decomposition

A single chain of spheres has been investigated experimentally, as shown schematically in Fig.1. The spheres were Grade 10 Chrome Steel of diameter 1 mm. Cylindrical holders for various lengths of chain were fabricated from photopolymer resin using Micro-stereolithography (MSL). The spheres were positioned so as to be just in contact under negligible pre-compression. The first sphere was excited harmonically by a longitudinal ultrasonic horn, which was driven by Agilent 33120A function/Arbitrary waveform generator and a power amplifier. This produced a resonant response at 73 kHz. Coupling gel was used between the first sphere and the transducer for good acoustic transmission as well as to decrease the possible pre-compression force. The last sphere was positioned against an aperture, so that the particle velocity waveform could be measured using a Polytec laser vibrometry system. The velocity signal of both the tip of ultrasonic horn and that of the last sphere in the chain were both recorded in this way, to allow a comparison between the two.
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Dromion solutions for nonlinear electron acoustic waves in space plasmas

Dromion solutions for nonlinear electron acoustic waves in space plasmas

ilar two-dimensional solitary structures have been studied by many authors (Djordjevic and Redekopp, 1977; Manakov, 1976; Ablowitz and Segur, 1979). However, none of these studies dealt with a nonlinear solution that had an exponen- tial decay in both dimensions. This lacuna was removed by the work of Boiti et al. (1989), who found coherent local- ized structures as a solution of (2+1) dimensional integrable partial differential equations which, unlike a lump or alge- braic solitons (Satsuma and Ablowitz, 1979; Janaki et al., 1991), decayed exponentially in both directions in the (x , y) plane. One characteristic feature of these solutions is that they involve two field variables. One of the variables represents the physical entity which is being evolved (the electric field amplitude, for example) and displays a local- ized structure in space. The other auxiliary variable shows a plane wave character with vanishing physical fields at the boundaries and is often called a ghost soliton (Hietarinta, 1990). The dromion solutions also require special time de- pendent boundary conditions which are described by those ghost solitons. These ghost solitons are in fact the line soli- tons (Fokas and Santini, 1989) mentioned earlier and repre- sent the “tracks” (dromos in Greek), along which the local- ized lumps of the physical variable travel. In fact, the lumps are located precisely at the intersection of two such tracks of the auxiliary variable. Since they are “driven” by their boundaries, they were, therefore, named as dromions (Fokas and Santini, 1990). Ever since their discovery the mathemat- ical properties of dromions have been investigated by many authors both analytically (Santini, 1990; Hietarinta, 1990; Hietarinta and Hirota, 1990; Radha and Lakshmanan, 1995), as well as numerically (Besse and Bruneau, 1998; Nishinari and Yajima, 1994; Nishinari et al., 1996).
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