Optical characteristics of the filamentary and diffuse modes in surface dielectric barrier discharge.

Surface dielectric barrier discharge (DBD) plasmas generally exhibits filamentary and diffuse discharges at atmospheric air. The focus of this investigation is on the different optical characteristics and quantitative research about morphological features of two discharge modes. The temporally and spatially resolved characteristics of discharge phenomenon together with the gas temperature are presented with microsecond time scale.

[Emission spectra of hydroxyl radical generated in air corona discharge].

In this paper, the relative emission intensity of the 309 nm transition band of hydroxyl radical (OH) was measured by a CCD imaging spectrometer in a pin-plane corona discharge scheme of one atmosphere pressure air injected with unsaturated water vapor from the central hole of the used pins. The influences of several factors on the OH radical production were investigated by relative emission intensity measurement. The production of OH radical increased with a limited increment of water vapor concentration in the mixed gas.