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Conditions for the existence of strong double layers

Published online by Cambridge University Press:  13 March 2009

N. Jelić
Affiliation:
Institute for Ion Physics, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
M. Čerček
Affiliation:
J. Stefan Institute, University of Ljubljana, POB 100, 61111 Ljubljana, Slovenia
M. Stanojević
Affiliation:
J. Stefan Institute, University of Ljubljana, POB 100, 61111 Ljubljana, Slovenia
T. Gyergyek
Affiliation:
J. Stefan Institute, University of Ljubljana, POB 100, 61111 Ljubljana, Slovenia

Abstract

We present the results of a theoretical investigation of the conditions for the existence of a stationary, strong, monotonic double layer. A model that includes finite temperatures both of the particle species accelerated by the double layer and of those reflected by it is developed on the basis of the general theory of double layers due to Andrews and Allen. A numerical solution of the model equations is presented and analysed. Explicit approximate formulae for the electron-to-ion current ratio (i.e. the Langmuir factor) and for the initial velocities (i.e. directional energies of the accelerated particles at the double-layer boundaries before acceleration) are also derived that fit almost exactly the exact numerical solution over a wide range of double-layer potentials. It is shown that in the cases in which the standard results of Langmuir and Bohm are an oversimplification, approximate formulae may be used instead of exact numerical solutions to obtain quite accurate results in a simple manner.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1994

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References

REFERENCES

Amemiya, H. & Nakamura, Y. 1986 Plasma Phys. 26, 1613.Google Scholar
Andersson, D. 1981 J. Phys. D 14, 1403.CrossRefGoogle Scholar
Andrews, J. G. & Allen, J. E. 1971 Proc. R. Soc. Lond. A 320, 459.Google Scholar
Block, L. P. 1972 Cosmic Electrodyn. 3, 349.Google Scholar
Bohm, D. 1949 Characteristics of Electrical Discharges in Magnetic Fields (ed. Guthry, A. & Wakening, R. K.), p. 77. McGraw-Hill.Google Scholar
Cartier, S. L. & Merlino, R. L. 1987 Phys. Fluids 30, 2549.CrossRefGoogle Scholar
Davidson, R. C. 1972 Methods in Nonlinear Plasma Theory. Academic.Google Scholar
Fujita, H., Matsuo, K. & Jagura, S. 1984 Phys. Fluids 27, 2948.CrossRefGoogle Scholar
Harrison, E. R. & Thompson, W. B. 1959 Proc. Phys. Soc. Lond. 72, 2145.Google Scholar
Jelić, N., čerček, M., Gyergyek, T. & Stanojević, M. 1993 Proceedings of 4th Symposium on Double Layers and Other Nonlinear Potential Structures in Plasmas, Innsbruck, July 1992 (ed. Schrittwieser, R.), p. 364. World Scientific.Google Scholar
Langmuir, I. R. 1929 Phys. Rev. 33, 954.CrossRefGoogle Scholar
Levine, J. S. & Crawford, F. W. 1980 J. Plasma Phys. 23, 223.CrossRefGoogle Scholar
Main, G. L. & Lam, S. H. 1987 J. Plasma Phys. 38, 287.CrossRefGoogle Scholar
Torven, S. & Andersson, D. 1979 J. Phys. D 12, 717.CrossRefGoogle Scholar