On electron energy distribution function measurements in microwave discharges sustained by propagating surface waves

Abstract
The possibility of measuring the electron energy distribution function in microwave discharges sustained by the field of propagating surface waves via a second derivative technique is demonstrated. The influence of different measuring probe orientations (axial or radial with respect to the discharge axis) on the measured electrodynamic surface wave parameters and distribution functions is examined. The electron energy distribution functions obtained by axial and radial probe orientation show different behaviour. Significant influence of the presence of probes on the space distribution of the radial electric field component outside the discharge is observed. The results show that it is more appropriate to use a radially orientated probe for diagnostics in microwave discharges created by surface waves.