Voltage, current and electron density measurements in an air radiofrequency plasma

Various RF discharges are widely used in different kinds of production technologies. Still, questions of quality improvement often arise. That leads companies to look for a way of improving and optimising production processes. This cannot be done without appropriate diagnostic techniques. Power input control is really alluring because of its simplicity in implementation. In most experiments the main characteristic for the RF discharge is its consumed power. Nevertheless, in most theoretical works, the rf voltage is taken to be constant, which makes comparisons between experimental and theoretical difficult. Using the technique mentioned above it is possible to get the desired results. Microwave methods to measure electron density are advantageous due to its time resolution possibilities. Moreover, it is also a non-intrusive in situ measurement technique. In this work a low-pressure radio-frequency (RF) air discharge is treated. Both methods are used for plasma diagnostics, and the most interesting results are presented