Numerical studies on the polarities of electromagnetic wave modes in a magnetoplasma-filled cylindrical waveguide

Abstract

The physical polarities of electromagnetic waves propagating in a magnetoplasma-filled cylindrical waveguide are studied by numerical calculations and simple analytical analyses. In the plane of the frequency–axial wave number, the obtained results show that dispersion curves of right-hand polarized (RHP) and left-hand polarized (LHP) electromagnetic waves propagating in an infinite magnetoplasma determine characteristic regions in which wave modes propagating in a magnetoplasma-filled cylindrical waveguide have different physical polarities. The frequency region slightly below and above $\omega_{{\rm r}_1}$ ($\omega_{{\rm r}_1}$ denotes the lower-branch frequency of the RHP electromagnetic wave propagating in an infinite magnetoplasma) is characterized by pure or physical dominant RHP modes. In the frequency region of $\omega_{\rm l}\,{<}\,\omega\,{<}\,\omega_{{\rm r}_2} (\omega_{\rm l}$ and $\omega_{{\rm r}_2}$ denote the frequency of the LHP wave and the upper-branch frequency of the RHP wave propagating in an infinite magnetoplasma), except for formal RHP waveguide ${\it EH}^{\rm u}$ modes with sufficient large axial wave numbers, all modes are pure or dominant physical LHP waves. The frequency region of $\omega\,{>}\,\omega_{{\rm r}_2}$ can be thought of as a RHP area. The physical polarity of wave modes clarified in this paper is helpful to understand the interaction between charged particles and waves propagating in a magnetoplasma-filled cylindrical waveguide.