Investigation of the transition between glow and streamer discharges in atmospheric air

Abstract

Generally, the parameter p • d (pressure × gap distance) in dielectric barrier discharge (DBD) controls the electrical breakdown and also the plasma characteristics. We investigated the optimum plasma transition p • d by controlling the pressure. To find the transition p • d (p • d tr ) condition, optical emission spectroscopy (OES) was used to measure emission spectra from the DBD. All p • d data were normalized by the second positive system of nitrogen molecules, the wavelength of which was 337.1 nm. Then we compared the relative intensities of species generated during the discharge by OES analysis. Species selected for comparison were the first negative system (FNS) of nitrogen molecules (391.4 nm) and atomic oxygen spectra (777.1 nm). Experimental results showed that relative intensities were almost constant as p • d decreased, but at specific p • d data, the intensity started to increase. The increase in FNS of nitrogen molecules means not only an increase in electron energy but also a change in the plasma mode, streamer to glow transition. In the case of DBD using alumina with 1 mm thickness applied ac power, the plasma transition occurred at the 1 Torr cm condition.

Low temperature co-fired ceramics plasma generator for atmospheric pressure gas spectroscopy

“…5. The obtained emission spectra for LTCC-based plasma generator were comparable with the ones presented in the literature [24,[27][28][29]. Peaks, which corresponds to certain transitions, are broaden and rather Gaussian-like than in shape of Dirac delta function.…”

Electron density and temperature of gas-temperature-dependent cryoplasma jet

“…In an atmospheric-pressure glow helium discharge, the emission from N 2 þ can be enhanced by means of the Penning reaction of inert helium gas with N 2 , 19 and the emission intensity of O from O 2 impurities is due to a similar reaction to that for N 2 þ in an atmospheric pressure plasma. 8,20 The emission intensities of N 2 and Ar abruptly increased at 70 K. On the other hand, at this temperature, the emission intensity of O suddenly decreased. It is known that oxygen is a very efficient quencher of He metastables.…”

Diagnostics and active species formation in an atmospheric pressure helium sterilization plasma source

“…Admitting that, N 2 molecules are mainly excited to the second positive system by collisions with electrons having energies higher than 11 eV and the first negative system of N þ 2 are mainly populated by collision with electrons with energies higher than 18.7 eV [17], the evolution of the emission intensities ratio of N þ 2 to N 2 could indicate the evolution of the electron temperature. In Fig.…”