Almeida, N. A.; Benilov, M. S.; Franklin, Raoul and Naidis, G. V.
|DOI (Digital Object Identifier) Link:||http://doi.org/10.1088/0022-3727/37/22/008|
|Google Scholar:||Look up in Google Scholar|
The ionization layer (presheath) separating a fully ionized low-temperature thermal plasma from the space-charge sheath adjacent to a solid surface is described by means of a (multi)fluid model. The character of the solution is governed by α, the ratio of the ionization length to the mean free path for ion–atom collisions. If α ≥ 1, the solution is determined by physically transparent boundary conditions, namely, by the Bohm criterion at the sheath edge and the condition of full ionization on the plasma side of the ionization layer. If α < 1, the latter condition becomes ineffective. An alternative boundary condition is found for a certain range of α below unity, αcr ≤ α < 1. An approximate approach which spans the whole range of α is suggested. While being incomplete theoretically, this approach is sufficient for practical purposes and gives results that are in agreement with experiment. On the other hand, the question of what is the lacking boundary condition in the range 0 < α < αcr remains open and challenging.
|Item Type:||Journal Article|
|Copyright Holders:||2004 IOP Publishing Ltd|
|Academic Unit/Department:||Science > Physical Sciences
|Depositing User:||Tracey Moore|
|Date Deposited:||12 Jun 2007|
|Last Modified:||14 Jan 2016 16:32|
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