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Title: Presheath structure of a dust-contaminated plasma

Abstract

The presheath structure of a dust-contaminated plasma is studied by taking into account the electron-impact ionization, the plasma loss due to the capture of electrons and ions by the dust grains, the ion-dust collisions, as well as the dust charge variations. It is shown that at the edge of the presheath with the sheath, there is a critical ion Mach number (the generalized Bohm criterion modified by the dust) which is exactly the same as that obtained from collisionless sheath model. On the other hand, depending on different equilibrium states of the bulk plasma, different connections between the bulk plasma and the presheath will be inferred. When the electron-impact ionization exactly balances the plasma loss, there is a smooth transition from the bulk plasma to the presheath, and both the ion velocity and the gradients of the velocity and density vanish at the edge of the presheath with the bulk plasma. When the plasma loss exceeds the ionization, the presheath starts at the point where the ion velocity equals the ambipolar diffusion velocity, i.e., the presheath profile is connected to the diffusion profile of the bulk plasma. When the ionization exceeds the plasma loss, the bulk plasma-presheath edge appears wheremore » the gradient of the ion density is zero but the gradient of the ion velocity is nonzero. For the plasma loss exceeding or being less than the ionization, numerical results reveal that the change of the dust density can result in opposite effects on the presheath profiles (shortening or broadening of the presheath region)« less

Authors:
;  [1]
  1. CAS Key Laboratory of Basic Plasma Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China) and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)
Publication Date:
OSTI Identifier:
20782472
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 13; Journal Issue: 1; Other Information: DOI: 10.1063/1.2158142; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMBIPOLAR DIFFUSION; BOHM CRITERION; BOUNDARY LAYERS; CAPTURE; CHARGED-PARTICLE TRANSPORT; DENSITY; DUSTS; ELECTRON COLLISIONS; ELECTRONS; EQUILIBRIUM; ION COLLISIONS; ION DENSITY; IONIZATION; IONS; MACH NUMBER; PLASMA; PLASMA DENSITY; PLASMA SHEATH; VARIATIONS

Citation Formats

Li Yangfang, and Ma, J.X. Presheath structure of a dust-contaminated plasma. United States: N. p., 2006. Web. doi:10.1063/1.2158142.
Li Yangfang, & Ma, J.X. Presheath structure of a dust-contaminated plasma. United States. doi:10.1063/1.2158142.
Li Yangfang, and Ma, J.X. Sun . "Presheath structure of a dust-contaminated plasma". United States. doi:10.1063/1.2158142.
@article{osti_20782472,
title = {Presheath structure of a dust-contaminated plasma},
author = {Li Yangfang and Ma, J.X.},
abstractNote = {The presheath structure of a dust-contaminated plasma is studied by taking into account the electron-impact ionization, the plasma loss due to the capture of electrons and ions by the dust grains, the ion-dust collisions, as well as the dust charge variations. It is shown that at the edge of the presheath with the sheath, there is a critical ion Mach number (the generalized Bohm criterion modified by the dust) which is exactly the same as that obtained from collisionless sheath model. On the other hand, depending on different equilibrium states of the bulk plasma, different connections between the bulk plasma and the presheath will be inferred. When the electron-impact ionization exactly balances the plasma loss, there is a smooth transition from the bulk plasma to the presheath, and both the ion velocity and the gradients of the velocity and density vanish at the edge of the presheath with the bulk plasma. When the plasma loss exceeds the ionization, the presheath starts at the point where the ion velocity equals the ambipolar diffusion velocity, i.e., the presheath profile is connected to the diffusion profile of the bulk plasma. When the ionization exceeds the plasma loss, the bulk plasma-presheath edge appears where the gradient of the ion density is zero but the gradient of the ion velocity is nonzero. For the plasma loss exceeding or being less than the ionization, numerical results reveal that the change of the dust density can result in opposite effects on the presheath profiles (shortening or broadening of the presheath region)},
doi = {10.1063/1.2158142},
journal = {Physics of Plasmas},
number = 1,
volume = 13,
place = {United States},
year = {Sun Jan 15 00:00:00 EST 2006},
month = {Sun Jan 15 00:00:00 EST 2006}
}