Abstract
In this paper, the emission spectra from plasma jet-water interaction is investigated. The plasma system consists of a quartz tube which is surrounded by two copper strips separated by 14 mm, the upper stripe is connected to AC high voltage power supply and the lower is grounded. A quartz-cuvette containing the water sample is placed at 13 mm down to the tube nozzle. Emission spectra from three regions; the distance between the two electrodes (A), the distance between the grounded electrode and the sample surface (B), and through the sample (C), are investigated. The results show clear differences between the spectra emitted from the three regions. Region A emits the highest intensities for the line spectra and argon 763 nm was the maximum. As well as, O radical emission spectra were detected with the highest intensities in region B. However, new bands and lines appear in the spectra from region C, due to interaction of the jet with water, depending on the water conditions and plasma operating parameters. These results declare that plasma jet interaction with water can be used as indicator for water quality and a detector for which species play the rule in plasma sterilization too.