The radial structure of a plasma column sustained by a surface wave

Abstract

The self-consistent radial profiles are obtained for a steady-state, surface-wave-sustained, unmagnetized argon plasma in a cylindrical dielectric tube surrounded by a conductor. The density profiles obtained using the correct constant mean-free-path ion–neutral collision differ considerably from those obtained using the common (but here quite incorrect) approximation of constant mean free time, but are little affected by changes in the profile of wave energy deposition. Various profiles for some typical cases are also compared for three different electron heat transport assumptions. These electron heat transport coefficients are as follows: (i) The correct value, (ii) 102× the correct value, to obtain the essentially isothermal case, and (iii) 10−2× the correct value, to approximate negligible heat transport (the adiabatic case). From the comparison of the temperature profiles, it became clear that the best electron heat transport simplification is to take the electrons to be isothermal [i.e., assumption (ii)], in which case only the total absorption per unit length is important, and not the details of the surface wave behavior.