Cold atmospheric plasma jet sustained with nanosecond voltage pulses

Summary form only given. Atmospheric-pressure glow discharge (APGD) jets separate the plasma generation region from the processing region, thus simultaneously attaining high plasma stability and active reaction chemistry. The vast majority of APGD jets reported so far employs sinusoidal excitation, although it has been known that non-sinusoidal excitation, through wave-shaped or pulsed voltage, offers a useful freedom to further improve APGD performance. Initial results from few reported studies of pulsed APGD jets have shown their general similarity to and contrast with sinusoidal APGD jets. However a direct comparison of pulsed and sinusoidal APGD jets remains elusive, thus casting an uncertainty of whether a pulsed APGD jet offers significant advantages. Given that pulsed APGD jets introduce additional system parameters including pulse width, pulse rise time and duty cycle, the answer to the above question will also significantly influence ways with which pulsed APGD jets can be optimized and the APGD technology can be advanced. In this contribution, we present an experimental study to directly compare electrical and optical characteristics of a pulsed APGD jet and its sinusoidal counterpart. Experimental methodologies used include current and voltage measurement, gas temperature measurement and optical detection of reactive plasma species. An example of pulsed excitation is shown to reduce the electrical energy consumption by a factor of 12 for producing the same amount of oxygen atoms. Therefore the pulsed APGD jet is an energy efficient enabler of useful plasma chemistry