Diagnostics of Non-Equilibrium High-Pressure Plasmas Generated by the Resistive Barrier Dtscharge

Summary form only given. Atmospheric pressure non-thermal plasmas have recently received increased attention because of several emerging applications. Recently, we presented a novel method to produce a non-thermal, large volume, atmospheric pressure plasma. This method used a similar configuration to the dielectric barrier discharge. However, instead of a dielectric, a resistive layer was used to cover at least one of the electrodes. The resistive barrier discharge (RDB) can be operated with DC or AC power supplies. In this paper, the discharge is operated with a 60 Hz AC power supply. The I-V characteristics of the discharge are studied with He and Ar as operating gases (with air impurity). When He is used as operating gas, the discharge current exhibits several spikes superimposed on an AC part. However, when Ar is used, the discharge is a typical filamentary discharge with current spikes of magnitudes around 10 mA. To identify the various chemical species present in the discharge volume, optical emission spectroscopy (OES) is applied. When He, mixed with air traces, is used the emission spectrum is dominated by excited N₂ and N₂ ⁺ . On the other hand, when Ar is used, the spectrum is dominated by excited N₂ and Ar, but no N₂ ⁺ emission bands are observed. The molecules´ rotational and vibrational temperatures are of significance in investigations of the discharge. The second positive system of the N₂ molecule is used to obtain the rotational and vibrational temperatures. It is found that the rotational temperature for a He background is about 300 K, and 500 K for Ar. The vibrational temperatures are about 2100 K and 1100 K for He and Ar, respectively