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The effect of gradients of density and static magnetic field on the propagation of surface waves and on wave–beam interaction

Published online by Cambridge University Press:  13 March 2009

V. V. Demchenko
Affiliation:
Atomic Energy Authority, Cairo
N. M. El-Siragy
Affiliation:
Atomic Energy Authority, Cairo
A. M. Hussein
Affiliation:
Atomic Energy Authority, Cairo

Abstract

The propagation of slow surface waves in an inhomogeneous plasma is investigated. Both ‘axial’ and ‘radial’ density gradients n(r) and those of the static magnetic field B0 are taken into account. It is demonstrated that the axial in- homogeneities n(z) and B0(z) result in the dependence of the natural surface- wave frequencies on the ‘axial’ co-ordinate z. The dependence ωSW(z) affects the phase velocity νph = ωswsol;K where K iS the propagation constant. So, in the case of surface-wave excitation by a charged particle beam in an ‘axially’ inhomogeneous plasma, the Cherenkov resonance ωSW= KV0 between the beam and the surface waves breaks, thereby reducing the growth rate of unstable oscillations. This phenomenon might be considered as the stabilization of the beam by the ‘axial’ density gradient. It is also shown that the ‘radial’ gradients n0(r) and B0(r) essentially affect the surface-wave natural frequencies as well. Dispersion equations, expressions for the natural frequencies and growth rates are obtaind, taking into account the gradients of the density and the static magnetic field.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1973

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References

REFERENCES

Barlow, H. N. & Brown, J. 1962 Radio Surface Waves. Oxford University Press.Google Scholar
Demchenko, V. V. & Zayed, K. E. 1972 J. Plasma Phys.Google Scholar
El-siragy, N. M., Pakhomov, V. I. & Zayed, K. E. 1971 Physics, 51, 260.Google Scholar
El-Siragy, N.M. & Pakhomov, V. I. 1969 Plasma Phys. 11, 707.CrossRefGoogle Scholar
Harrison, E. R. & Stringer, T. E. 1963 Proc. Phys. Soc. B 82, 700.CrossRefGoogle Scholar
Maxum, B. T. & Trivelpiece, A. W. 1965 J. Appl. Phys. 36, 481.CrossRefGoogle Scholar
Mikhailovsky, A. & Pashitsky, E. 1965 Zh. eksp. teor. Fiz. 48, 1787.Google Scholar
Pakhomov, V. I. & Stepanov, K. N. 1968 Zh. tekh. Fiz. 38, 796.Google Scholar
Pakhomov, V. I. & Zayed, K. E. 1970 Physics, 50, 467.Google Scholar
Talwar, S. P. & Kalra, G. Z. 1967 Nucl. Fusion, 7, 17.CrossRefGoogle Scholar