Hostname: page-component-6bf8c574d5-mggfc Total loading time: 0 Render date: 2025-02-23T13:53:36.525Z Has data issue: false hasContentIssue false
  • English
  • Français

Joining sheath to plasma in electronegative gases at low pressures using matched asymptotic approximations

Published online by Cambridge University Press:  01 November 1999

M. S. BENILOV  and
R. N. FRANKLIN
M. S. BENILOV
Affiliation:
Departamento de Fisica, Universidade da Madeira, 9000 Funchal, Portugal
R. N. FRANKLIN
Affiliation:
Oxford Research Unit, The Open University, Boars Hill, Oxford OX1 5HR, England
Get access Rights & Permissions [Opens in a new window]

Abstract

The method of matched asymptotic expansions is used to examine the structure of the plasma sheath of the positive column at low pressure in electronegative gases using the fluid model to describe the positive-ion motion. It is shown that at low negative-ion concentrations, and at high concentrations, the structure is that of a plasma joined to a thin sheath, but that for the electron/negative-ion temperature ratio Te/Tn ≡ ε > 5 + √24, and for a well-defined range of A ≡ nn0/ne0 (the central negative ion to electron density ratio) and for small Debye length, there is a more complex structure with a central negative-ion-dominated plasma surrounded by a quasiplasma in which density oscillations may occur before joining to a sheath. This is in agreement with recent computations using the same model.

Type
Research Article
Information
Journal of Plasma Physics , Volume 62 , Issue 5 , November 1999 , pp. 541 - 559
Copyright
1999 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)