Guided Waves on an Infinite Cylindrical Cavity in a Magneto-ionic Medium I. Circularly Symmetric Mode†

Abstract

ABSTRACT The characteristics of the guided waves supported by an infinitely long cylindrical cavity of free-space immersed in a magneto-ionic medium are investigated for the case of the magnetostatic field in the direction of the axis of the column. The frequency characteristics of certain limiting and special propagating conditions such as transition from fast to slow wave solutions, resonance and cut-off as well as the dispersion characteristics under propagating conditions are studied as a function of the ratio R of the gyromagnetic to plasma frequencies, and the radius of the column. The lowest-order mode is found to start as a fast wave, then becomes a slow wave and, if R<1, has a resonance at 1/√2 times the upper hybrid resonant frequency Ωu. For very small radius of the column, both the fast and the slow wave portions of the lowest-order mode have backward wave regions and the conditions which are sufficient for the existence of the backward waves are discussed. All the other higher-order modes are...