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Electromagnetic cyclotron-loss-cone instability associated with weakly relativistic electrons

Published online by Cambridge University Press:  13 March 2009

H. K. Wong
Affiliation:
Institute for Physical Science and Technology, University of Maryland
C. S. Wu
Affiliation:
Institute for Physical Science and Technology, University of Maryland
F. J. Ke
Affiliation:
Institute for Physical Science and Technology, University of Maryland
R. S. Schneider
Affiliation:
Instituto de Física, Universidade Federal do Rio Grande do Sul, 90000 Porto Alegre, RS, Brazil
L. F. Ziebell
Affiliation:
Instituto de Física, Universidade Federal do Rio Grande do Sul, 90000 Porto Alegre, RS, Brazil

Abstract

The amplification of fast extraordinary mode waves with frequencies very close to the electron cyclotron frequency is investigated for a plasma which consists of a weakly relativistic electron component with a loss-cone type distribution and a cold background electron component. The basic mechanism of the amplification is attributed to a relativistic cyclotron resonance between the wave and the energetic electrons. The method employed in the present analysis enables us to solve the dispersion relation in a self-consistent manner for arbitrary ratio of the densities of the energetic and background electrons. It is found that the maximum growth rates occur at certain values of ω2pe2e and the angular dependence of the growth rate is sensitive to the ratios ω2pe2e and ne/nb. Here ωpe and Ωe are the electron plasma frequency and the electron cyclotron frequency, respectively, and ne and nb denote the number densities of the energetic and background electrons, respectively.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1982

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References

REFERENCES

Alfvén, H. & Fälthammar, C. G. 1963 Cosmical Electrodynamics. Oxford University Press.Google Scholar
Benson, R. F. & Calvert, W. 1979 Geophys. Res. Lett. 6, 479.Google Scholar
Calvert, W. 1981 J. Geophys. Res. 86, 76.CrossRefGoogle Scholar
Dory, R. A., Guest, G. E. & Harris, E. G. 1965 Phys. Rev. Lett. 14, 131.CrossRefGoogle Scholar
Dusenbery, P. B. & Lyons, L. R. 1982 J. Geophys. Res. (To be published.)Google Scholar
Geller, R., Hopfgarten, N., Jacquot, B. & Jacquot, C. 1974 J. Plasma Phys. 12, 467.Google Scholar
Gurnett, D. A. 1974 J. Geophys. Res. 79, 4227.CrossRefGoogle Scholar
Gurnett, D. A. & Green, J. L. 1978 J. Geophys. Res. 83, 689.Google Scholar
Hewitt, R. G., Melrose, D. B. & Rönnmark, K. G. 1982 Aust. J. Phys. (To be published.)Google Scholar
Hirschfield, J. L. & Bekefi, G. 1963 Nature, 198, 20.CrossRefGoogle Scholar
Kaiser, M. L., Alexander, J. K., Riddle, A. C., Pearce, J. B. & Warwick, J. W. 1978 Geophys. Res. Lett. 5, 857.CrossRefGoogle Scholar
Lee, L. C. & Wu, C. S. 1980 Phys. Fluids, 23, 1348.Google Scholar
Le Queau, D., Pellat, R. & Roux, A. 1982 Phys. Fluids. (To be published.)Google Scholar
Melrose, D. B., Hewitt, R. G. & Rönnmark, K. G. 1982 J. Geophys. Res. 87, 5140.Google Scholar
Mozer, F. S., Carlson, C. W., Hudson, M. K., Torbert, R. B., Parady, B., Yatteau, J. & Kelley, M. C. 1977 Phys. Rev. Lett. 37, 1393.Google Scholar
Omidi, M. & Gurnett, D. A. 1982 J. Geophys. Res. 87, 2377.Google Scholar
Quon, B. M. & Wong, A. Y. 1976 Phys. Rev. Lett. 37, 1393.Google Scholar
Shkarofsky, I. P. 1966 Phys. Fluids, 9, 561.CrossRefGoogle Scholar
Twiss, Q. R. 1958 Aust. J. Phys. 11, 564.Google Scholar
Wu, C. S. & Lee, L. C. 1979 Astrophys. J. 230, 621.Google Scholar
Wu, C. S., Wong, H. K., Gorney, D. J. & Lee, L. C. 1982 J. Geophys. Res. 87, 4476.CrossRefGoogle Scholar