Analysis of Axial Electric Field in Thermal Plasma-Loaded Helix Traveling-Wave Tube With Dielectric-Loaded Waveguide

A helix-type slow-wave structure (SWS) filled with thermal plasma is immersed in an axial guide magnetic field. The sheath helix enclosed within a loss-free wall in which the gap between the helix and the outer wall is filled with a dielectric. Using the boundary condition of two regions, the dispersion relation of the SWS is derived. Solutions are found numerically, which correspond to both the extraordinary and ordinary solutions. The trend of change for the phase velocity and radial profile of the axial electric field is analyzed, respectively, in different plasma temperature. Some useful results are given.