About the helix plasma antenna: effective factors on characteristics of radiation

چکیده مقاله

In this paper, a plasma waveguide including a dielectric cover sur- rounded by metallic helical sheath is investigated as a helix plasma antenna. By solving the wave equation, the components of electric and magnetic fields of hybrid modes for each region is calculated. The collisional approximation for background plasma is used at first and in the second stage a magnetized plasma will be considered as the electromagnetic media in the helical sheath. Applying suitable boundary conditions, the dispersion relation of slow waves in tera- hertz frequency region is investigated for two configurations men- tioned above. Effect of several parameters such as the helix angle, the geometry dimensions, the dielectric constant of dielectric layer, the cyclotron frequency and the plasma frequency on the popula- tion of dispersion branches of lower hybrid modes, is investigated. Also, the graphs of normalized radiation power in plasma region to the radiation power in vacuum region are presented.