Dependence of the emission characteristics of magnetized surface-wave plasmas on the azimuthal configuration of the wave field

A 1D plasma-wave model initially developed for describing a plasma sustained by a surface wave in the azimuthally symmetric configuration (m=0) was modified for simulating surface waves in the dipolar mode (m = 1). Using this model, it is shown that the maintenance limit for unmagnetized plasmas in the symmetric mode, which, as was previously determined, requires that the product of the wave frequency and the plasma radius be smaller than 2 GHz cm, is no longer valid for magnetized plasmas. Comparison of calculated and measured radial distributions of argon atoms in a radiative excited state shows that changes observed in this distribution when varying some of the operating conditions can be explained by a switching of the discharge from one mode to the other. Conditions for selection of the mode are derived from considerations on wave propagation and power dissipation along the plasma column. (C) 1997 American Institute of Physics. [S0021-8979(97)03421-X].