Axial structure of a shielded axially magnetized plasma column sustained by a dipolar electromagnetic mode

We consider an axially magnetized cold plasma column contained in a dielectric tube, surrounded by a vacuum and shielded by a metallic cylinder. Closed-form analytical expressions for the wave dispersion relation, wave power, absorbed power and wave attenuation coefficient of the right-hand circularly polarized dipolar electromagnetic waves are given. In view of plasma production by such waves their phase diagrams are discussed. The external DC magnetic field is found to facilitate the column sustainment, especially at low values of the product plasma radius*wave frequency, and can remove occasionally occurring wave reflections from the column end. In the presence of a metallic shield one can observe fast wave propagation at higher powers. The axial structure of plasma columns sustained by the fundamental plasma mode HE_II has been obtained under a free-fall/diffusion gas-discharge regime. In the limit of an infinite metallic cylinder radius the results for the wave phase and attenuation coefficients coincide with those derived numerically by Margot and Moisan (1991).