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Switched-on evolution due to a temporal electron charge drifting subthermally through a warm collisional plasma

Published online by Cambridge University Press:  13 March 2009

Lim Chee-Seng
Affiliation:
Department of Mathematics, National University of Singapore, Singapore 0511, Republic of Singapore

Abstract

An electron charge is suddenly switched on while drifting through a warm collisional plasma. It acts thereafter with an arbitrary time-dependence. The evolution of the plasma, initially at rest, is considered in two and three dimensions. A general solution is first established for drift-modified slow plasma modes and then employed in subthermal drift analysis. Its abrupt switch-on causes the electron charge to release, during subthermal drift, a fully symmetric thermal front Г which subsequently expands ahead of it into an undisturbed receding expanse. A transversely symmetric response develops inside Г. On switch-off, the drifting charge releases another thermal front Г0 which also precedes it but trails non-concentrically behind Г. Plasma response continues after switch-off. Response properties between Г and Г0 differ strikingly from those inside Г0. Applications are next considered, first in three dimensions, for a subthermal pulsating electron with a generally complex frequency ω. The prepermanent state response inside Г comprises an axisymmetric dominant component ø plus a spherically symmetric transient component øtr. ø acquires the frequency ω. øtr has amplitudes dependent on and wave crests independent of both frequency ω and drift; it suffers a fast (slow) ω–independent temporal attenuation in a collisional (collisionless) plasma. The geometrical drift wave structure of ø is closely examined for real ω and a collisionless plasma. Every energy surface associated with ø nucleates at the electron; from there, it evolves slower than a phase surface, which eventually ‘disappears’ past Г. The leading energy surface, which nucleated at switch-on, develops permanently inside Г; it serves as an energy front that seals off the energy sustaining ø since switch-on. Finally, the two-dimensional evolving drift field of an activated antenna line is computed.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1985

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References

REFERENCES

Chambers, Ll. G. 1965 J. Fluid Mech. 22, 209.CrossRefGoogle Scholar
Chambers, Ll. G. 1967 Proc. Edinburgh Math. Soc. 15, 125.CrossRefGoogle Scholar
Chee-Seng, L., Majumdar, S. R. & Westbrook, D. R. 1976 Proc. Roy. Soc. A 349, 205.Google Scholar
Chee-Seng, L. 1977 Quart. Appl. Math. 35, 321.CrossRefGoogle Scholar
Chee-Seng, L. 1978 Proc. Roy. Soc. A 364, 181.Google Scholar
Chenevier, P., Dolique, J. M. & Perès, H. 1973 J. Plasma Phys. 10, 185.CrossRefGoogle Scholar
Cooper, G. 1969 Phys. Fluids, 12, 2707.CrossRefGoogle Scholar
Erdélyi, A., Magnus, W., Oberhettinger, F. & Tricomi, F. G. 1954 Tables of Integral Transforms. McGraw-Hill.Google Scholar
Fiala, V. 1970 IEEE Trans. AP-18, 834.CrossRefGoogle Scholar
Fiala, V. 1973 J. Plasma Phys. 10, 371.CrossRefGoogle Scholar
Fiala, V. 1979 Czech. J. Phys. B 29, 589.CrossRefGoogle Scholar
Hebenstreit, H. & Suchy, K. 1978 Kleinheubacher Ber. 21, 135.Google Scholar
Hebenstreit, H. 1979 Z. Naturforsch. 34a, 155.CrossRefGoogle Scholar
Joyce, G. & Montgomery, D. 1967 Phys. Fluids, 10, 2017.CrossRefGoogle Scholar
Krall, N. A. & Trivelpiece, A. W. 1973 Principles of Plasma Physics. McGraw-Hill.CrossRefGoogle Scholar
Kuehl, H. H. 1974 Phys. Fluids, 17, 1275.CrossRefGoogle Scholar
Laing, E. W., Lamont, A. & Fielding, P. J. 1971 J. Plasma Phys. 5, 441.CrossRefGoogle Scholar
Lee, K. F. 1974 Phys. Fluids, 17, 1220.CrossRefGoogle Scholar
Lighthill, M. J. 1960 Phil. Trans. Roy. Soc. A 252, 397.Google Scholar
Michel, E. 1976 J. Plasma Phys. 15, 395.CrossRefGoogle Scholar
Montgomery, D., Joyce, G. & Sugihara, R. 1968 Plasma Phys. 10, 681.CrossRefGoogle Scholar
Morse, P. M. & Feshbach, H. 1953 Methode of Theoretical Physics, vol. 1. McGraw-Hill.Google Scholar
Mourgues, G., Fijalkow, E. & Feix, M. R. 1980 Plasma Phys. 22, 367.Google Scholar
Stenflo, L., Yu, M. Y. & Shukla, P. K. 1973 Phys. Fluids, 16, 450.CrossRefGoogle Scholar
Storey, L. R. O. & Thiel, J. 1978 Phys. Fluids, 21, 2325.CrossRefGoogle Scholar
Storey, L. R. O., Thiel, J. & Boswell, R. W. 1980 Phys. Fluids, 23, 654.CrossRefGoogle Scholar
Wait, J. R. 1964 Can. J. Phys. 42, 1760.CrossRefGoogle Scholar
Wang, C.-L., Joyce, G. & Nicholson, D. R. 1981 J. Plasma Phys. 25, 225.CrossRefGoogle Scholar