Electrical characterization of argon and nitrogen based cold plasma

In this paper, a dielectric barrier discharge plasma based atmospheric pressure plasma jet has been generated in a floating helix and floating end ring electrode configuration using mixture of argon and nitrogen gases (50: 50 ratio). This configuration is subjected to a range of supply frequencies (10-25 kHz) and supply voltages (6.5-9.5 kV) at a fixed rate of gas flow rate (i.e., 1 l/min). The electrical characterization of the plasma jet has been carried out using a high voltage probe and current transformer. The current-voltage characteristics have been analyzed, and the power consumed by the device has been estimated at different applied combinations of supply frequency and voltages for optimum power consumption and maximum jet length. A comparative analysis of the results of the above experiments has shown that maximum power consumed by the device in helix electrode configuration with end ring is 19 W for (Ar+N-2) mixture as compared to only 12 mW and 7.7mW for Ar and He gas respectively (With end ring), this may be due to the main ionization mechanisms which are different depending on the working gas. Furthermore, maximum jet length of 42mm has been obtained for He gas at 6 kV/25 kHz due to penning ionization process in comparison to jet lengths of only 32mm for Ar gas and jet length of only 26mm for Ar+N-2 mixture. The obtained average power consumed and maximum jet length for mixture of (Ar+N-2) gases are 6.5W and 26 mm.