Spectroscopic and electrical characters of SBD plasma excited by bipolar nanosecond pulse in atmospheric air

In this paper, an atmospheric surface barrier discharge (SBD) generated by annular electrodes in quartz tube is presented through employing bipolar nanosecond pulse voltage in air. The discharge images, waveforms of pulse voltage and discharge current, and optical emission spectra emitted from the discharges are recorded and calculated. A spectra simulation method is developed to separate the overlap of the secondary diffraction spectra which are produced by grating in monochromator, and N-2 (B-3 Pi(g) -> A(3)Sigma(+)(u)) and O (3p(5)P -> 3s(5)S(2)degrees) are extracted. The effects of pulse voltage and discharge power on the emission intensities of OH (A(2)Sigma(+) -> X-2 Pi(i)), N-2(+) (B-2 Sigma(+)(u) -> X-2 Sigma(+)(g)), N-2 (C-3 Pi(u) -> B-3 Pi(g)), N-2 (B-3 Pi(g) -> A(3)Sigma(+)(u)), and O (3p(5)P -> 3s(5)S(2)degrees) are investigated. It is found that increasing the pulse peak voltage can lead to an easier formation of N-2(+) (B-2 Sigma(+)(u)) than that of N-2 (C-3 Pi(u)). Additionally, vibrational and rotational temperatures of the plasma are determined by comparing the experimental and simulated spectra of N-2(+) (B-2 Sigma(+)(u) -> X-2 Sigma(+)(g)), and the results show that the vibrational and rotational temperatures are 3250 +/- 20 K and 350 +/- 5 K under the pulse peak voltage of 28 kV, respectively. (C) 2016 Elsevier B.V. All rights reserved.