Basic Theoretical Methods in Microwave Plasma Polarimetry: Quasi-Isotropic Approximation, Stokes Vector Formalism and Complex Polarization Angle Method
- Space Research Institute, Profsoyuznaya St. 82/34, Moscow 117997 (Russian Federation)
- Institute of Physics, Maritime University of Szczecin, Waly Chrobrego 1/., 70-500 Szczecin (Poland)
- Institute of Radio Astronomy, 4 Krasnoznamyonnaya St., Kharkov 61002 (Ukraine)
- Max Planck Institute for Plasma Physics, Greifswald, Wendelsteinstrasse D-17491 (Germany)
Three different theoretical approaches are presented: quasi-isotropic approximation (QIA), Stokes vector formalism and complex polarization angle method, which allow describing polarization of electromagnetic waves in weakly anisotropic plasma. QIA stems directly from the Maxwell equations under assumption of weak anisotropy and has a form of coupled differential equations for the transverse components of the electromagnetic wave field. Being applied to high frequency (microwave or IR) electromagnetic waves in magnetized plasma, QIA describes combined action of Faraday and Cotton-Mouton phenomena. QIA takes into account curvature and torsion of the ray, describes normal modes conversion in the inhomogeneous plasma and allows specifying area of applicability of the method.In distinction to QIA, Stokes vector formalism (SVF) deals with quantities, quadratic in a wave field. It is shown (and this is the main result of the paper) that equation for Stokes vector evolution can be derived directly from QIA. This evidences deep unity of two seemingly different approaches. In fact QIA suggests somewhat more information than SVF; in particular, it describes the phases of both transverse components of the electromagnetic field, whereas SVF operates only with the phase difference.At last, the coupled equations of the quasi-isotropic approximation can be reduced to a single equation for complex polarization angle (CPA), which describes both the shape and orientation of the polarization ellipse. In turn, equation for CPA allows obtaining equations for traditional parameters of polarization ellipse, which in fact are equivalent to the equation for Stokes vector evolution. It is pointed out that every method under discussion has its own advantages plasma polarimetry.
- OSTI ID:
- 21136895
- Journal Information:
- AIP Conference Proceedings, Vol. 993, Issue 1; Conference: PLASMA 2007: International conference on research and applications of plasmas; 4. German-Polish conference on plasma diagnostics for fusion and applications; 6. French-Polish seminar on thermal plasma in space and laboratory, Greifswald (Germany), 16-19 Oct 2007; Other Information: DOI: 10.1063/1.2909096; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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