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Ion-acoustic double layers in multi-species plasmas maintained by negative ions

Published online by Cambridge University Press:  13 March 2009

Frank Verheest
Affiliation:
Instituut voor theoretische mechanika, Rijksuniversiteit Gent, Krijgslaan 281, B-9000 Gent, Belgium

Abstract

A study is made of ion-acoustic double layers in a plasma consisting of any number of cold positive and negative ion (and cold electron) species in addition to one isothermal electron population. The Sagdeev potential is obtained in general, together with limits on both compressive and rarefactive solutions for ion-acoustic double layers and/or solitons. Weak ion-acoustic double layers are described by a modified Korteweg-de Vries equation. Such double layers are not possible in plasmas with only positive ion species and one electron population. When one or more negative ion and/or cold electron species are included above a certain threshold density, rarefactive ion-acoustic double layers occur, but no compressive ones. The double-layer form of the potential is given, together with an application to a plasma with one positive and one negative ion component. It is shown that there is indeed such a threshold density for the negative ion density, depending on the charge-to-mass ratios of both types of ions. The threshold density is determined numerically for a range of such ratios and discussed in view of possible relevance to auroral and experimental plasmas. In the discussion, cold electrons can play the role of the negative ion species.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1989

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References

REFERENCES

Baboolal, S., Bharuthram, R. & Hellberg, M. A. 1988 J. Plasma Phys. 40, 163.CrossRefGoogle Scholar
Bharuthram, R. & Shukla, P. K. 1986 Phys. Fluids, 29, 3214.CrossRefGoogle Scholar
Broer, L. J. F. & Sluijter, F. W. 1977 Phys. Fluids, 20, 1458.CrossRefGoogle Scholar
Buti, B. 1980 Phys. Lett. 76A, 251.CrossRefGoogle Scholar
Das, P. K. & Verheest, F. 1989 J. Plasma Phys. 41, 139.CrossRefGoogle Scholar
Nakamura, Y. 1987 a Proceedings of the 18th International Conference on Phenomena in Ionized Gases, Invited Papers, p. 116. Adam Hilger.Google Scholar
Nakamura, Y. 1987 b J. Plasma Phys. 38, 461.CrossRefGoogle Scholar
Nakamura, Y., Ferreira, J. L. & Ludwig, G. O. 1985 J. Plasma Phys. 33, 237.CrossRefGoogle Scholar
Nakamura, Y. & Tsukabayashi, I. 1985 J. Plasma Phys. 34, 401.Google Scholar
Reddy, R. V. & Tagare, S. G. 1988 Analytic solution for ion-acoustic soliton in a two ion-plasma consisting of negative ions. University of Hyderabad Preprint.Google Scholar
Sagdeev, R. Z. 1966 Reviews of Plasma Physics, vol. 4 (ed. Leontovich, M. A.), p. 23. Consultants Bureau.Google Scholar
Sato, T. & Okuda, H. 1980 Phys. Rev. Lett. 44, 740.Google Scholar
Stix, T. H. 1962 The Theory of Plasma Waves. McGraw-Hill.Google Scholar
Sutradhar, S. & Bujarbarua, S. 1987 J. Phys. Soc. Jpn, 56, 139.CrossRefGoogle Scholar
Tagare, S. G. 1986 J. Plasma Phys. 36, 301.Google Scholar
Temerin, M., Cerny, K., Lotko, W. & Mozer, F. S. 1982 Phys. Rev. Lett. 48, 1175.CrossRefGoogle Scholar
Torvén, S. & Andersson, D. 1979 J. Phys., D 12, 717.Google Scholar
Verheest, F. 1988 J. Plasma Phys. 39, 71.Google Scholar
Watanabe, S. 1984 J. Phys. Soc. Jpn, 53, 950.CrossRefGoogle Scholar