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Discharges in Aerosols and Dusty Plasmas
Published in Alexander Fridman, Lawrence A. Kennedy, Plasma Physics and Engineering, 2021
Alexander Fridman, Lawrence A. Kennedy
The 10–500 nm dust particles may acquire a very large charge Zde = 102−105e. As a result, the mean energy of Coulomb interaction between them is proportional to Zd2 and can exceed the particle thermal energy. Hence the dusty plasma can be highly nonideal with the charged particles playing the role of multiply charged heavy ions (Ichimaru, 1982). The strong Coulomb interaction between particles results in the formation of ordered special structures in dusty plasma similar to those in liquids and solids. Critical phenomena of phase transitions between “gas” and “liquid” and “liquid” and “solid” structures can be observed in dusty plasma as well (Fortov, 2001). The crystalline structures formed by charged particles in dusty plasma are usually referred to as Coulomb crystals (Ikezi, 1986; Chu and Lin, 1994; Thomas et al., 1994). Interaction of charged particles in dusty plasma can provide not only space, but also time–space structures. This leads not only to modification of wave and oscillation modes existing in nondusty plasmas, but also to the appearance of new modes typical only for dusty plasmas.
Nonlinear Dust Kinetic Alfvén Waves in a Dust-Ion Plasma with Ions Following q-Nonextensive Velocity Distribution
Published in B. Raneesh, Nandakumar Kalarikkal, Jemy James, Anju K. Nair, Plasma and Fusion Science, 2018
Two-component dusty plasma model corresponds to a state where most of the electrons from the ambient plasma are attached to the dust grain surface so that we may assume that n <<Zn,, where n (n.) is the unperturbed electron (dust grain) number density and Zd is the number of electrons residing on the dust grain surface. However, the depletion of electrons cannot be complete because the minimum value of the ratio between the electron and ion number densities turns out to be (me/mi)1/2 as the grain surface potential approaches zero, where m(m) is the electron (ion) mass. Here, the dusty plasma may be regarded approximately as two-component plasma composed of negatively charged dust grains and ions. The latter shield the dust grains. The relevance of this model can be found in planetary ring systems, such as in Saturn’s F-rings [5,9,28], and in comets (e.g., Halley’s comet [13, 26]). This model is valid because for a situation (n <<Zn.), we have m /m << 1, where n. is the unperturbed ion number density. Hence, at equilibrium, we have n¿0 — Zd?rdo.
The existence and propagation of dust acoustic waves in quantum four-component plasma
Published in Waves in Random and Complex Media, 2021
Essam M. Abulwafa, Atalla M. El-Hanbaly, Hayam F. Darweesh
Dust plasma is known as a system of electron-ion plasma with highly charged multi-component dust particulates of ultra-small size. Due to its wide applications in different areas, such as space plasma, astrophysical plasma, and in industry, the classical dust plasma interaction has been investigated theoretically and experimentally [1–18]. In classical dusty plasmas, the existence and propagation of dust acoustic waves attract great attention due to their vital role in understanding many astrophysical phenomena and laboratory applications. Some of these phenomena and applications are, such as plasma crystal, coating, and etching of thin films, radiofrequency plasma discharge, low-temperature physics, the lower part of Earth’s ionosphere and magnetosphere, interstellar medium, asteroid zones, planetary rings, cometary tails, etc. [1–6]. Many observations have been made for dusty plasma situations which have only dust grains with a negative charge by collecting the plasma particles. However, other observations proved that the dust particles could be positively charged via other charging processes such as secondary emission of electrons from the surface of the dust grains, thermionic emission induced by radiative heating, and photoemission in the presence of a flux of ultraviolet photons [7,8]. Moreover, other situations in space such as Jupiter’s magnetosphere, upper and lower mesosphere and comet tails insure the existence of both negative and positive dust particles [9,10] and consequently yield new type of waves propagating in plasma media. The linear and nonlinear waves of dust acoustic (DA) and dust ion acoustic (DIA) are the most important types in systems of dusty plasma [11–13].
Nonplanar dust acoustic waves in a four-component dusty plasma with double spectral distributed electrons: modulational instability and rogue waves
Published in Waves in Random and Complex Media, 2021
S. K. El-Labany, W. F. El-Taibany, A. A. El-Tantawy, N. A. Zedan
There has been a great attention to study the different nonlinear characteristics of dusty plasmas [1] due to its presence in various astrophysical environments and laboratories [1–3]. Dusty plasma can be identified as an electron-ion plasma with an additional charged component of small micron-sized particulates. Positive and negative dust represent extra components. This component contributes to increase the complexity of the system. Complex systems help efficiently in describing the physical circumstances various cosmic environments [1–5] such as planetary rings [1], in circumsolar and the Phobos dust rings, in the interplanetary medium [2, 3], in cometary comae and tails [1], and in interstellar molecular clouds [2]. Moreover, the gigantic charged dust grains, contribute in creating new eigenmodes such as dust acoustic (DA) mode. This mode was theoretically predicted by Rao et al [1] and then approved experimentally by Barkan et al. [6]. Several studies about dust acoustic waves (DAWs) in three components dusty plasma (dust, electrons, ions) were reported [1, 7, 8]. In these studies, the dust was considered as negatively charged grain. In addition, the existence of positively charged particles was detected in several space regions, such as upper mesosphere [9], cometery tails [3] and Jupiter’s magnetosphere [9, 10] and also in plasma experiments [11, 12]. Chow et al. [13] have explained the situation related to the dust size and charge. They clarified that dust particles with small size have positive charges while those with larger size have negative ones. On the other hand, the opposite situation, i.e. larger grains being positive and the smaller ones being negative, is achieved by the so-called triboelectric charging. Fortov et al. [14] demonstrated the mechanisms by which dust grains gain positive charges. Those mechanisms are (i) photoemission in the presence ultraviolate radiation, (ii) thermionic emission stimulated by radiative heating, and (iii) secondary emission of electrons from the surface of dust grains.
Specifications of dust-ion-acoustic shock waves affected by dust charge variation in four-component dissipative quantum plasma
Published in Radiation Effects and Defects in Solids, 2019
Noushin Pishbin, Mahmoud Reza Rouhani, Naser Alinejad
Dusty plasma is a fascinating research area and has received considerable attention due to its applications in space and in industry (1). In most of the laboratory and astrophysical plasmas, in addition the usual components such as electrons, positrons, and ions, the impurities or dust particles can exist and, thus, form dusty plasma; for example in tokamak edges, cometary tails and planetary ring systems. The dust particles lead to a change in equilibrium condition and create new types of ion-acoustic waves. The linear and nonlinear structures of these new waves have been studied by many researchers (2–8). Some of these investigations have been done in quantum dusty plasma models (9–14). Dusty plasma, with an extremely low temperature and high number density of particles, is known as the quantum model. In this state, the de Broglie wavelength is similar to or larger than the average interparticle distance,, i.e. (15). Where with mj and VTj are the mass and thermal velocity of jth species, respectively. Quantum effects can be found in several examples; such as: quantum dots, nanowires (16), intense laser-solid density plasma experiments (17), ultracold plasmas (18), ultra-small electronic devices (19) and dense astrophysical environments (20–22). Due to these wide applications, a number of researchers have studied quantum effects using various mathematical models such as the Schrodinger–Poisson model, Wigner–Poisson model and quantum hydrodynamic (QHD) model (23–26). QHD model is applicable to the investigation of various collective processes at short scale such as waves, nonlinear structures and instabilities, etc. in quantum plasmas. This model generalizes the fluid model with taking into account the macroscopic variables only, i.e. fluid velocity, density, stress tensor and electrostatic potential.