Axial structure of a plasma column produced by a large-amplitude electromagnetic surface wave

Abstract
Electromagnetic surface waves in the rf and microwave frequency range can be used to produce long large/small‐diameter plasma columns. We propose a theory of surface‐wave‐produced plasmas at two different low‐pressure gas‐discharge regimes, diffusion and recombination, respectively. For a given regime the axial plasma density profile is specified by two quantities: a numerical parameter σ=ωR/c (ω being the wave frequency, R the tube radius, and c denoting the speed of light) and the collision frequency ν (ν≪ω). Our theory predicts the magnitude of the axial electron number density gradient. The very good agreement between the experimentally measured plasma density gradients and the theoretically calculated ones for diffusion‐controlled surface‐wave‐produced plasma columns confirms the adequacy of the proposed model.