A novel aspect of dust in plasma

Abstract

Nonlinear screening of the dust grains immersed in a homogenous fully ionized electron-ion plasma is investigated. Assuming conservation of entropy, an important relation is obtained between the maximum potential (and therefore the charge) of the dust grain and the temperature of the electrons. The Thomas-Fermi equation is derived for the potential of a dust grain in a nondegenerate plasma suggesting the existence of dust atom with a well defined atomic radius. Furthermore, based on the Born-Oppenheimer approximation, the notion of a dust-grain molecule is introduced in which the protons act like a kind of “glue” which binds two negatively charged dust grains together, and the motion of the grains have little influence on that binding force. Finally, considering the weak interaction between the proton clouds of two dust grains, an expression of exchange energy is obtained.

Existence of Dust Atoms & Modified OML Theory

“…This scenario is well described by the expression (1) of the electron density, from which follows the maximum potential field to be . On the other hand, the potential field becomes maximum only on the surface of dust grain, i.e., Combining last two relations, we obtain a very important relation between the charge number and the temperature, for a given radius of the dust grain, (2) where r D is the radius of the dust grain. This simple relation (2) exactly defines the surface charge of the dust grain and is valid as long as the mean distance between dust grains is larger than the Debye length.…”

“…We therefore conclude that the existence of such gigantic atoms is indeed a possibility. From the motion of a particle in an external field we find the radius of the proton in the last shell far from the grain surface will be [2]. Evidently the distance r last << Debye length.…”

Modulation instability of lower hybrid waves leading to cusp solitons in electron–positron(hole)–ion Thomas Fermi plasma

“…The study of these phenomena is also very important because of the possibility of heating. Recently, coupling between fast lattice ions and electrons in piezoelectric semiconductor plasma using a semi‐classical hydrodynamic model was studied, which led to the possible formation of the subsonic cusp‐like solitons …”

“…Recently, coupling between fast lattice ions and electrons in piezoelectric semiconductor plasma using a semi-classical hydrodynamic model was studied, which led to the possible formation of the subsonic cusp-like solitons. [47] This manuscript is organized in the following manner. In Section 2, the basic formulation of two types of lower hybrid waves is given, and the respective dispersion relations are obtained in Section 3.…”

Dust-acoustic waves and stability in the permeating dusty plasma. I. Maxwellian distribution

“…[1][2][3][4][5] The dust grains may acquire charges through a variety of interactions with electrons and ions. 6,7 These interactions can also take place between the dust grains and they can make a response to an external perturbation. The dusty plasmas exist ubiquitously in the space regions such as the interstellar clouds, the circumstellar clouds, the interplanetary space, the comets, the planetary rings, the Earth's atmosphere, and the lower ionosphere, etc.…”