Twisted Landau damping rates in multi-component dusty plasmas

A kinetic formulation is developed to investigate low-frequency dust ion acoustic waves (DIAWs) and dust acoustic waves (DAWs) as well as numerically for a four-component, collisionless, unmagnetized dusty plasma, using the linearized Vlasov-Poisson model for species obeying the Maxwellian distribution. In particular, the dynamics of low-frequency DIAWs is investigated by considering two cases. In the first case, ions and positive dust particles are assumed to be dynamically adiabatic while the negative dust particles are static in the background. In second case, the ions are taken adiabatic, while both positive and negative dust particles are static in the background. For DAWs, the ions are assumed to be isothermal, while both positive and negative dust species are considered adiabatic. Electrons are assumed to be isothermal in all cases. The linear characteristics and Landau damping rates for DIAWs and DAWs are investigated with effects of the dust particle concentrations and different temperature ratios. It is noted that for higher values of positive dust concentration, DIAWs (DAWs) are less (more) damped. It is also observed that the damping rate increases (decreases) as T i approaches T e for DIAWs (DAWs). It is worth adding here that the theoretical results presented here are supported by numerical analyses and illustrations. The relevance of the study to laboratory and cosmic plasmas is also pointed out. KEYWORDSacoustic waves, dusty plasma, kinetic theory, Landau damping, longitudinal response function INTRODUCTIONA great deal of interest has been shown in the study of dusty plasmas in the last few decades with a view to understanding the propagation of linear and non-linear excitations. Dusty plasmas are very abundant and exist in the laboratory [1,2] as well as in space and astrophysical surroundings [3][4][5][6] such as cometary tails, planetary rings, and the interstellar medium. The existence of a high density of dust grains in a plasma system causes the generation of some complex and collective processes that introduce several new modes, for example, dust acoustic waves (DAWs), [7] dust lattice waves (DLWs), [8,9] , dust drift waves (DDWs), and dust ion acoustic waves (DIAWs).[10] Earlier investigations had been carried out to study the most common dusty plasma system consisting of negative dust particles, ions, and electrons. [7][8][9][10] The main reason for considering the negative dust grain is the fundamental process of charging, that is, the collection of particles with high thermal energy, namely electrons, by the dust grain. However, some new charging mechanisms have been investigated due to which the dust grain can be charged positively. These charging mechanisms are (a) photoemission in the presence of ultraviolet (UV) photons, [11,12] (b) thermionic emission caused by radiative heating, [13] and (c) secondary electron emission from the surface of the dust grains. [14] The co-existence of negatively and positively charged dust grains has been investigated in space [12,14] and laboratory pl...

“…Defining the non-dimensional parameters → r pd and k → k D , the normalized dispersion relation for DAWs can be obtained from Equation (32) in the following form:…”

Section: Dust Acoustic Wavesmentioning

confidence: 99%

“…[28][29][30][31][32] One of the important characteristics of DAWs and DIAWs is the Landau damping, which is a fundamental element in the kinetic description of plasma waves. [28][29][30][31][32] One of the important characteristics of DAWs and DIAWs is the Landau damping, which is a fundamental element in the kinetic description of plasma waves.…”

mentioning

confidence: 99%

Kinetic treatment of acoustic waves in a four‐component dusty plasma

Ahmad

Farooq

et al. 2018

“…In laboratory plasma, these waves have been observed experimentally by Barkan et al. [12][13][14][15][16] In the kinetic description of plasma waves, Landau damping is a fundamental element that is one of the important characteristics of DAW and DIAW and their dynamics. [12][13][14][15][16] In the kinetic description of plasma waves, Landau damping is a fundamental element that is one of the important characteristics of DAW and DIAW and their dynamics.…”

Section: Introductionmentioning

confidence: 99%

Effect of non‐extensivity parameter q on the damping rate of dust ion acoustic waves in non‐extensive dusty plasma

Rehman

Ahmad

Hamza

2018

Kinetic theory has been applied to study the damping characteristics of dust ion acoustic waves (DIAWs) in a dusty plasma comprising q-non-extensive distributed electrons and ions, while the dust particles are considered extensive following the Maxwellian velocity distribution function. It is found that the results of the three-dimensional velocity distribution function are more accurate compared to the results of the one-dimensional velocity distribution function. The numerical solution of the dispersion relation is carried out to study the effect of the non-extensivity parameter q on the dispersion, the damping rate, and the range of the values of the normalized wavenumber ( k D ) for which the DIAWs are weakly damped. It is found that the change in the value of the electron non-extensivity parameter q e has a minor effect on the dispersion, the damping rate, and the range of the values of the normalized wavenumber ( k D ) for which the DIAWs are weakly damped, while on the other hand, ion non-extensivity parameter q i has a strong effect on these arguments. The effect of other parameters, such as the ratio of electron to ion number density and ratio of electron to ion temperature, on the damping characteristics of DIAWs is also highlighted.

“…[8] This study demonstrated that the growth rate is enhanced with increasing target pair ion densities and electronic flow speed, while it reduces with streaming ion densities. [19,20] In the present work, we employ a Vlasov-Poisson kinetic model to investigate a twisted IA wave instability in a permeating plasma with finite OAM. A solar wind plasma streams through a cometary plasma in the presence of interstellar dust component to add to the complexity and gives rise to low-frequency unstable modes.…”

Section: Introductionmentioning

confidence: 99%

“…The twisted plasma waves have also been studied in multicomponent non-Maxellian plasmas, where distinct features involving OAM states have been discussed to show non-conventional behaviour of plasma waves and oscillations. [19,20] In the present work, we employ a Vlasov-Poisson kinetic model to investigate a twisted IA wave instability in a permeating plasma with finite OAM. In our model, we consider the interpenetration of solar wind into a cometary environment.…”

mentioning

confidence: 99%

Kinetic instability of twisted excitations in permeating plasma environments

Bukhari

Khan

Ali

2018

Self Cite

Twisted ion-acoustic excitations and the existence of kinetic instability are investigated in this study, accounting for finite orbital angular momentum states. For this purpose, a quasi-neutral electron-ion plasma is considered, which permeates through another (target) plasma. The Vlasov-Poisson model is used to obtain explicit expressions for wave dispersion and kinetic instability, including the contributions from the orbital angular momentum. It is shown that the existence of instability is a result of the exceeding electron speed as compared to the ion-acoustic speed, with a strong contribution of twist in the wave. Furthermore, it is found that a planner ion-acoustic wave propagates as a slow wave in comparison with the non-planar (twisted) wave. The results are analysed numerically for typical plasmas found in space and astrophysical environments.