Igniting large gap atmospheric pressure diffused air plasma by perforated dielectric and applying DC/AC voltage

Producing a large gap diffuse non-equilibrium atmospheric pressure air plasma has challenged plasma material processing. The atmospheric pressure air plasmas are known to be nonuniform and unstable when the spacing between the electrodes exceeds 10 mm. This work brings new insight into the large gap atmospheric pressure plasma generation for material processing. In this work, we proposed a new discharge configuration to overcome the limitations of nonuniformities and the instabilities of large gap atmospheric pressure gas discharge. The perforated dielectric and the AC superimposed DC voltage excitation schemes were introduced to produce the diffuse electric discharge with the gas gap spacing of 80 mm by the peak voltage of 23.6 kV. The scheme successfully demonstrated planer and volumetric large gap plasma using perforated Mica dielectric. A sawtooth waveform voltage with an amplitude of 1.6 kV and 9.7 kHz was superimposed on the DC voltage employing perforated dielectrics to ignite such a gas discharge. The new structure could also produce large gas gap spacing cold plasma for material processing and disinfection apparatuses.