Characterization of a dielectric barrier discharge operating in an open reactor with flowing helium

Abstract

A dielectric barrier discharge (DBD) generated by flowing helium between the parallel-plate electrodes of an open air reactor has been characterized using time resolved optical and electrical measurements. A sinusoidal voltage of up to 5 kV (peak to peak) of frequencies from 3 to 50 kHz has been applied to the discharge electrodes. The helium flow rate is varied up to 10 litre min−1. The adjustment of flow rate allows the creation of uniform DBDs with optimized input power equal to 120 ± 10 mW cm−3. At flow rates from 4 to 6 litre min−1 a uniform DBD is obtained. The maxima in the line intensities of and helium at 391.4 nm and 706.5 nm, respectively, under those conditions indicate the importance of helium metastables and in sustaining such a discharge. The power efficiency and discharge current show maxima when the DBD in He/air is uniform. The gas temperature during the discharge has been measured as 360 ± 20 K.