Guided Waves on an Infinite Cylindrical Cavity in a Magneto-ionic Medium II. Dipolar Modes†

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 dipolar case for which the fields have an exp (imφ) azimuthal variation, where φ is the angular variable and m ± 1, is treated. The characteristics of the transition, the resonance and the cut-off frequencies of the guided waves ore discussed with particular reference to their dependences on the radius of the free-space column. The dispersion characteristics under propagating conditions are studied in detail both for the special case of vanishing static magnetic field and for the general case of finite magneto-static field corresponding to the two typical values of the ratio R of the gyromagnetic to the plasma frequencies. The lowest-order mode is found to be of the modified TE type and has special features such as that it can have forward or backward wave...