Spectroscopic study of a stationary surface-wave sustained argon plasma column at atmospheric pressure

A spectroscopic study of an argon surface wave plasma column at atmospheric pressure under steady-state conditions shows that we are dealing with a tw o-temperature (2T) discharge whose excitation kinetics are controlled by el ectron collisions (electron excitation kinetic plasma). A partial local Sah a equilibrium in the excitation space is reached from which the 4s and 4p l evels are excluded. The absorbed high frequency (HF) power per electron for the maintenance of the discharge (the parameter theta) was found to be a m agnitude increasing with the electron density, contrary to what occurs at l ow pressure. Modifying the work conditions, such as gas flow and HF power, we obtained plasmas that are similar in structure when the end of the plasm a is used as a reference position. (C) 2000 Elsevier Science B.V. All right s reserved.