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Title: Charge screening in a plasma with an external ionization source

Abstract

An asymptotic theory for the screening of the electric field of a dust particle or a spherical probe in a plasma with an external steady and/or internal (proportional to the electron density) gas ionization source has been developed for the first time. It has been established that the screening of the charge of a spherical body adsorbing the charge of the incident plasma particles is described by a superposition of two exponentials with different screening constants. The two exponentials are retained even in the absence of nonequilibrium fluxes on the macroparticle and only in the special case of an isothermal plasma does the screening become Debye one. The screening length is determined by the ratio of the electron-ion, {beta}{sub ei}, and Langevin, {beta}{sub L} = 4{pi}e{mu}{sub i} (where {mu}{sub i} is the ion mobility), recombination coefficients. If {beta}{sub L} >> {beta}{sub ei}, then it is much larger than the electron Debye length. The ions in an isothermal plasma have been found to give the same contribution to the screening as the electrons if the electron-ion recombination coefficient exceeds the Langevin ion recombination coefficient by a factor of 2 or more, {beta}{sub ei} {>=} 2{beta}{sub L}. The Vlasov equation is usedmore » to analyze the asymptotic behavior of the macroparticle potential in a collisionless plasma.« less

Authors:
 [1]; ;  [2]; ;  [3]
  1. Troitsk Institute for Innovation and Fusion Research, State Research Center of the Russian Federation (Russian Federation), E-mail: fav@triniti.ru
  2. National Academy of Sciences of Ukraine, Bogolyubov Institute for Theoretical Physics (Ukraine)
  3. Troitsk Institute for Innovation and Fusion Research, State Research Center of the Russian Federation (Russian Federation)
Publication Date:
OSTI Identifier:
21072544
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 104; Journal Issue: 1; Other Information: DOI: 10.1134/S1063776107010153; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ASYMPTOTIC SOLUTIONS; BOLTZMANN-VLASOV EQUATION; COLLISIONLESS PLASMA; DEBYE LENGTH; DUSTS; ELECTRIC FIELDS; ELECTRON DENSITY; ELECTRON-ION COLLISIONS; ELECTRONS; ION MOBILITY; IONIZATION; IONS; PARTICLES; POTENTIALS; RECOMBINATION; SPHERICAL CONFIGURATION

Citation Formats

Filippov, A. V., Zagorodny, A. G., Momot, A. I., Pal, A. F., and Starostin, A. N. Charge screening in a plasma with an external ionization source. United States: N. p., 2007. Web. doi:10.1134/S1063776107010153.
Filippov, A. V., Zagorodny, A. G., Momot, A. I., Pal, A. F., & Starostin, A. N. Charge screening in a plasma with an external ionization source. United States. doi:10.1134/S1063776107010153.
Filippov, A. V., Zagorodny, A. G., Momot, A. I., Pal, A. F., and Starostin, A. N. Thu . "Charge screening in a plasma with an external ionization source". United States. doi:10.1134/S1063776107010153.
@article{osti_21072544,
title = {Charge screening in a plasma with an external ionization source},
author = {Filippov, A. V. and Zagorodny, A. G. and Momot, A. I. and Pal, A. F. and Starostin, A. N.},
abstractNote = {An asymptotic theory for the screening of the electric field of a dust particle or a spherical probe in a plasma with an external steady and/or internal (proportional to the electron density) gas ionization source has been developed for the first time. It has been established that the screening of the charge of a spherical body adsorbing the charge of the incident plasma particles is described by a superposition of two exponentials with different screening constants. The two exponentials are retained even in the absence of nonequilibrium fluxes on the macroparticle and only in the special case of an isothermal plasma does the screening become Debye one. The screening length is determined by the ratio of the electron-ion, {beta}{sub ei}, and Langevin, {beta}{sub L} = 4{pi}e{mu}{sub i} (where {mu}{sub i} is the ion mobility), recombination coefficients. If {beta}{sub L} >> {beta}{sub ei}, then it is much larger than the electron Debye length. The ions in an isothermal plasma have been found to give the same contribution to the screening as the electrons if the electron-ion recombination coefficient exceeds the Langevin ion recombination coefficient by a factor of 2 or more, {beta}{sub ei} {>=} 2{beta}{sub L}. The Vlasov equation is used to analyze the asymptotic behavior of the macroparticle potential in a collisionless plasma.},
doi = {10.1134/S1063776107010153},
journal = {Journal of Experimental and Theoretical Physics},
number = 1,
volume = 104,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
  • The ionic composition of the plasma produced by an external ionization source in dry air at atmospheric pressure and room temperature and the screening of the electric field of a dust particle in such a plasma have been investigated. The point sink model based on the diffusion-drift approximation has been used to solve the screening problem. We have established that the main species of ions in the plasma under consideration are O{sub 4}{sup +}, O{sub 2}{sup -}, and O{sub 4}{sup -} and that the dust particle potential distribution is described by a superposition of four exponentials with four different constants.more » We show that the first constant coincides with the inverse Debye length, the second is described by the inverse ambipolar diffusion length of the positive and negative plasma components in the characteristic time of their recombination, the third is determined by the conversion of negative ions, and the fourth is determined by the attachment and recombination of electrons and diatomic ions.« less
  • New gauge-invariant definitions for the total charge on a static Yang-Mills source are suggested which we argue are better suited for determining when true color screening has occurred. In particular, these new definitions imply that the Abelian Coulomb solution for a simple electric'' dipole source made up of two opposite point charges has zero total source charge and therefore no color screening. With the definition of total source charge previously suggested by other authors, such a source would have a total source charge of 2{ital q} and therefore a screening charge in the field of {minus}2{ital q}, where {ital q}more » is the magnitude of the charge of either point charge. Our definitions for more general solutions are not unique because of the path dependence of the parallel transport of charges. Suggestions for removing this ambiguity are offered, but it is not known if a unique, physically meaningful definition of total source charge in fact exists.« less
  • The structure of the field of a distributed external source in a homogeneous magnetoactive plasma is found under the conditions of efficient excitation of plasma resonances by it with allowance for spatial dispersion and particle collisions. It is shown that at a distance from the source, the field loses the resonance character; parameters are found, the relation between which determines the degree of influence of electromagnetic, dispersional, and dissipative effects on the spatial evolution of the resonance structure.
  • A determination is made of energy losses and of the structure of a quasi-steady-state dipole field that excites resonance oscillations in the inhomogeneous layer of a magnetized plasma. It is shown that the level of losses is a substantial function of the geometry of the system (the distance between the source and the resonance region, and the mutual orientation of the inhomogeneity gradient, the dipole moment, and the magnetic field) and the degree of inhomogeneity of the medium.