Scattering of a normally incident extraordinary (Z mode) wave by a cylindrical density depletion aligned with an external static magnetic field in a magnetoplasma is studied. This problem is of importance for wave diagnostics of plasma density irregularities that can be formed under natural conditions of near-Earth space or during the modification of the ionosphere by high-power radio waves. The emphasis is placed on the behavior of scattering characteristics of the density depletion in the case where the frequency of the incident plane wave coincides with one of the resonant frequencies of such a plasma structure. The field patterns observed in the resonance scattering regimes are calculated and analyzed. The results obtained can be helpful in understanding the basic properties of resonance scattering of electromagnetic waves from the field-aligned density irregularities and planning the related ionospheric and laboratory experiments.

The energy-flow structure during the resonance scattering of a normally incident plane electromagnetic Hwave by a gyrotropic cylinder is studied. The main attention is focused on the bifurcations of the time-averaged Poynting vector field at the surface and volume plasmon resonances in the case where the cylinder is aligned with a gyrotropy axis. The behaviour of the Poynting vector field in this case is compared with that observed during the scattering by an isotropic cylinder, and significant differences in the energy-flow structures in the two cases are revealed. Conditions are found under which the maximum magnitude of the Poynting vector at the boundary of a gyrotropic cylinder turns out to be much greater than that at the boundary of an isotropic scatterer of the same shape and size.

Abstract-The scattering of an obliquely incident H-polarized plane electromagnetic wave by a magnetized plasma column is studied. It is assumed that the column is located in free space and aligned with an external static magnetic field. The emphasis is placed on the case where the angular frequency of the incident wave coincides with one of the surface-or volume-plasmon resonance frequencies of the column. The spatial structures of the field and energy flow patterns in the near zone of the column are analyzed, and the location of the regions with a greatly enhanced magnitude of the timeaveraged Poynting vector is determined. It is shown that the sign reversal of the longitudinal energy-flow component that is parallel to the column axis can occur when passing across the boundary between the inner region of the column and the surrounding medium.

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