A comparison between experimental results and a fluid description of a low pressure discharge driven by a double-saddle antenna

The diffusion of a 160 W argon plasma from a 13.56 MHz cylindrical (6 cm diameter, 20 cm long) magnetic field-free source into a 30 cm diameter and 20 cm long diffusion chamber has been investigated experimentally and by simulation. The rf power is coupled to the plasma using a double-saddle antenna. Experimentally, the radial plasma density and potential profiles across the source exit and the electron temperature are measured using an energy analyser operating in ion and electron collection mode, respectively. A two-dimensional fluid simulation model, stimulated by the experimental results, has been developed; it includes a specific power deposition scheme based on previous analytical work on the double-saddle antenna. A good agreement between the experimental and simulation results is obtained in terms of density and plasma potential radial profiles and electron temperature.