General Dispersion Relation for Electromagnetic Surface Waves in Partially-Filled Cylindrical Plasma Waveguides with Finite Wall Conductivity

Abstract

In the absence of an external magnetic field, surface plasma waves can travel over the plasma-vacuum interface in a cold homogenous plasma encased in a cylindrical metallic waveguide as long as the plasma only partially fills the waveguide. In this work, we examine the impact of the metallic wall’s finite conductivity on the dispersion relation of surface plasma waves. We obtain a general dispersion relation for any azimuthal harmonic number by starting with Maxwell’s equations and using the field-matching approach. The analysis and numerical computations are then concentrated on the electrostatic dipolar mode. The dispersion relation is investigated for a range of wall conductivities and waveguide radius to plasma radius ratios. Additionally, our results match well with earlier research and are compatible with the limiting scenario of perfectly conducting walls. Understanding wave dynamics is essential for beam diagnostics and wakefield studies in plasma-based antennas, waveguide design, and accelerator physics research. This work offers fresh perspectives on electromagnetic wave propagation in practical plasma waveguides.