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Scintillations in a magnetized plasma. Part 1. The mutual coherence function

Published online by Cambridge University Press:  13 March 2009

D. B. Melrose
D. B. Melrose
Affiliation:
Research Centre for Theoretical Astrophysics, University of Sydney, NSW 2006, Australia
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Extract

A standard theory of strong scintillations in an isotropic medium is extended to the case of polarized radiation propagating through a weakly anisotropic, randomly inhomogeneous, magnetized plasma. A hierarchy of moments of the radiationfield is defined, with an nth-order moment being an nth-rank polarization tensor, and the tensor equation for the evolution of an arbitrary moment is derived. Emphasis isplaced on the mutual coherence function (a second moment), which is rewritten in terms of the Stokes parameters. The evolution of the polarized radiation through the randomly inhomogeneous, weakly anisotropic medium is described in terms ofa matrix equation for the Stokes vector. It is shown that the theory implies that a depolarization occurs as a result ofsuch propagation. This corresponds to a decrease in the degree of linear polarization for propagation through a weakly anisotropic plasma. The rate of depolarization is estimated, and an interpretation is suggested. The polarization dependence of the angular size of the apparent image is determined. Two counter-intuitive results are found: that the image canhave a circularly polarized component even for an unpolarized source, and that the angular size of the linearly polarized source can decrease. These are interpreted in terms of random variations in the ray path with opposite signs for the two natural modes, resulting in a separation of the centroids of the images in the two circular polarizations.

Type
Articles
Information
Journal of Plasma Physics , Volume 50 , Issue 2 , October 1993 , pp. 267 - 281
Copyright
Copyright © Cambridge University Press 1993

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References

REFERENCES

Chernov, L. A. 1960 Wave Propagation in a Random Medium. Dover.CrossRefGoogle Scholar
Cordes, J. M., Rickett, B. J. & Backer, D. C. 1988 Radio Wave Scattering in the Interstellar Medium. American Institute of Physics.Google Scholar
Erukhimov, L. M. & Kirsch, P. I. 1973 Izv. Vyssh. Uchebn. Zaved. Radiofiz. 16, 1783.Google Scholar
Fante, R. L. 1975 Proc. IEEE 63, 1669.CrossRefGoogle Scholar
Fante, R. L. 1980 Proc. IEEE 63, 1424.CrossRefGoogle Scholar
Gochelashvily, K. S. & Shishov, V. I. 1971 Optica Acta 19, 327.CrossRefGoogle Scholar
Gochelashvily, K. S. & Shishov, V. I. 1972 Optica Acta 18, 313.CrossRefGoogle Scholar
Gochelashvily, K. S. & Shishov, V. I. 1975 Opt. Quantum Electron. 7, 524.CrossRefGoogle Scholar
Ishimaru, A. 1978a Wave Propagation and Scattering in Random Media. Vol. 1. Single Scattering and Transport Theory. Academic.Google Scholar
Ishimaru, A. 1978b Wave Propagation and Scattering in Random Media. Vol. 2. Multiple Scattering, Turbulence, Rough Surfaces, and Remote Sensing. Academic.Google Scholar
Kukushkin, A. V. & Ol'yak, M. R. 1991 Radiophys. Quantum Electron. 33, 1002.CrossRefGoogle Scholar
Lazio, T. J., Spangler, S. R. & Cordes, J. M. 1990 Astrohys. J. 363, 515.CrossRefGoogle Scholar
Lee, L. C. & Jokipii, J. R. 1975 Astrophys. J. 196, 695.CrossRefGoogle Scholar
Melrose, D. B. 1983 Aust. J. Phys. 36, 775.CrossRefGoogle Scholar
Melrose, D. B. 1993 J. Plasma Phys. 50, 283.CrossRefGoogle Scholar
Melrose, D. B. & McPhedran, R. C. 1991 Electromagnetic Processes in Dispersive Media. Cambridge University Press.CrossRefGoogle Scholar
Narayan, R. 1992 Phil. Trans. R. Soc. Lond. A 341, 151.Google Scholar
Prokhorov, A. M., Bunkin, F. V., Gochelashvily, K. S. & Shishov, V. I. 1975 Proc. IEEE 63, 790.CrossRefGoogle Scholar
Rickett, B. J. 1977 Ann. Rev. Astron. Astrophys. 15, 479.CrossRefGoogle Scholar
Rickett, B. J. 1977 Ann. Rev. Astron. Astrophys. 28, 561.CrossRefGoogle Scholar
Rumsey, V. H. 1975 Radio Sci. 10, 107.CrossRefGoogle Scholar
Simonetti, J. H., Cordes, J. M. & Spangler, S. R. 1984 Astrophys. J. 284, 126.CrossRefGoogle Scholar
Tamoikin, V. V. & Zamek, I. G. 1974 Izv. Vyssh. Uchebn. Zaved. Radiofiz. 17, 31.Google Scholar
Tatarski, V. I. 1961 Wave Propagation in a Turbulent Medium. Dover.CrossRefGoogle Scholar
Tatarski, V. I. & Zavortnyi, V. U. 1980 Prog. Optics 18, 204.CrossRefGoogle Scholar
Uscinski, B. J. 1977 The Elements of Wave Propagation in Random Media. McGraw-Hill.Google Scholar
Uscinski, B. J. 1982 Proc. R. Soc. Lond. A 380, 137.Google Scholar