In this paper a free air pressure plasma generator (APPG) is designed and evaluated. The generator is based on quarter wave helical coil in order to obtain the high electric field intensity. After an analytical study, a finite element simulation is constructed in order to better model the electric field around the coil and determine the resonant frequency based on the distributed capacitor formed between the coil and the ground plane. Using the data from simulation, the helical coil is constructed and plasma generation in free air is obtained. Based on practical measurements from the experiment, a simple spice model of the plasma is constructed in order to further improve the system and better understand the plasma properties.

Keywords: Atmospheric-pressure plasmas, Helical antennas, Finite element analysis, Plasma simulation