Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-27T14:32:09.395Z Has data issue: false hasContentIssue false

The growth and decay of resonant plasma oscillations excited by a small pulsed dipole

Published online by Cambridge University Press:  13 March 2009

J. A. Fejer
Affiliation:
University of California, La Jolla, California
Wai-Mao Yu
Affiliation:
University of California, La Jolla, California

Abstract

The application of integration by the method of stationary phase to resonant oscillations excited by a small pulsed dipole is outlined. Both the growth and the decay of the oscillations near the plasma frequency are determined by this method at a fixed distance from the dipole, first in the absence and then in the presence of an external magnetic field. It is shown that Landau damping must be taken into account in the calculation of the growth but not of the decay. The oscillations are shown to spread out with a speed that is about half the mean thermal speed of electrons.

Only the decay, not the growth, of the oscifiations near harmonics of the cyclotron frequency can be calculated by the same method. It is shown, moreover, that the amplitude, calculated for an observation point that moves away with sateffite velocity in an ionospheric environment, is only valid for time delays longer than about a minute. Such a result is therefore of no practical interest because the resonances observed from sateffites only last a few milliseconds. The erroneous nature of using such a result and the need for a different approach, such as that used in earlier work by the first author, are thus demonstrated.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1969

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Budden, K. G. 1961 Radio Waves in the Ionosphere. Cambridge.Google Scholar
Calvert, W. & Goe, G. B. 1963 J. Geophys. Res. 68, 6113.CrossRefGoogle Scholar
Deering, W. D. & Fejer, J. A. 1965 Phys. Fluids 8, 2066.Google Scholar
Dougherty, J. P. & Monaghan, J. J. 1966 Proc. Roy. Soc. A 289, 214.Google Scholar
Fejer, J. A. & Culvert, W. 1964 J. Geophys. Res. 69, 5049.CrossRefGoogle Scholar
Fried, B. D. & Conte, S. D. 1961 The Plasma Dispersion Function. New York: Academic Press Inc.Google Scholar
Fried, B. D., Hedrick, C. L. & McCune, J., 1968 Phys. Fluids 11, 249.CrossRefGoogle Scholar
Heikkila, W. J., Eaker, N., Fejer, J. A., Tipple, K. R., Hugill, J., Schneible, D. E. & Calvert, W. 1968 J. Geophys. Res. 73, 3511.CrossRefGoogle Scholar
Knecht, R. W. & Russell, S. 1962 J. Geophys. Res. 67, 1178.CrossRefGoogle Scholar
Knecht, R. W., Van Zandt, T. E. & Russell, S. 1961 J. Geophys. Res. 66, 3078.CrossRefGoogle Scholar
Lockwood, G. E. K. 1963 Can. J. Phys. 41, 190.CrossRefGoogle Scholar
Nuttall, J. 1965 Phys. Fluids 8, 286.CrossRefGoogle Scholar
Polkinghorne, J. C. 1961 The analytic properties of perturbation theory, p. 65. In Dispersion Relations (ed. Screaton, G. R.). Oliver and Boyd.Google Scholar
Shkarofsky, I. P. 1966 Duration of cyclotron harmonic resonances observed by satellites. RCA Victor Co., Res. Lab. Report 7-801-44.Google Scholar
Stix, T. H. 1962 The Theory of Plasma Waves. McGraw-Hill.Google Scholar
Sturrock, P. A. 1965 Phys. Fluids 8, 88.Google Scholar
Weitzner, H. 1964 Phys. Fluids 7, 72.CrossRefGoogle Scholar