Modeling of a plasma column produced and sustained by a traveling electromagnetic wave in the presence of a constant axial magnetic field

We present the basic equations for modeling a plasma column produced and sustained by a traveling electromagnetic wave in the presence of a constant external magnetic field. The model consists of two equations-a local-dispersion relationship and a wave-energy-balance equation-and a relation between the absorbed wave power per unit length averaged across the column (proportional to the squared-wave electric field) and the local electron number density. The dispersion relation and the balance equation are derived in explicit forms and depend on two numerical parameters σ=ωR/c (ω being the wave angular frequency, R the plasma column radius, c speed of light) and Ω=ω_c/ω (ω_c is the electron cyclotron frequency). The limit of an infinite external magnetic field (Ω-->∞) is also considered. The influence of the two parameters Ω and σ on the dimensionless axial profiles of the wave characteristics and plasma column density, obtained by numerical solution of the basic equations, has been studied for two different gas-discharge regimes. A three-dimensional wave structure has been obtained, and it is shown that the wave can be a generalized surface mode, a pure surface, or a pseudosurface one. The results obtained are in agreement with the available experimental data.