Effect of air flow on the micro-discharge dynamics in an array of integrated coaxial microhollow dielectric barrier discharges

Abstract

The micro-discharge properties and evolution in a 2D array of integrated coaxial microhollow dielectric barrier discharges are studied by using highly time-resolved electrical and optical diagnostics. The study is focused on the effect of the gas flow rate and gas residence time on discharge properties. The investigated integrated coaxial microhollow discharge geometry allows operating the discharge at exceptionally small residence times, which can be equal to or even smaller than the discharge period, at reasonable gas flow rates. The gas flow has an impact on gas heating, residual humidity, pre-ionization density and the densities of excited and reactive species produced by previous discharges. A unique voltage-charge plot is obtained with elongated periods without discharge activity. A very significant effect of flow on NO emission is observed that relates to the impact of flow on the NO production in these micro-discharges. Using the emission intensities of molecular bands of the second positive system of nitrogen and the first negative system of the nitrogen ion, effective reduced electric field strengths are obtained with a maximum equal to 870 Td. The reduced electric field decreases with increasing gas flow rate. This behavior is consistent with the reduction of the overall discharge intensity due to a reduced amount of charges present in the discharge gap. Both the flow rate and a reduction in water impurity changing the ion mobility can be responsible for the different effective electric field distributions at the highest and no flow conditions.

Rapid inactivation of airborne porcine reproductive and respiratory syndrome virus using an atmospheric pressure air plasma

“…The corresponding waveforms were recorded by a digital oscilloscope (DPO2024B, 200 MHz, 1 GS/s; Tektronix). The power ( P ) dissipated in the discharge is calculated from the voltage–charge (Lissajous) plots using the following equation [ 65 ] : where T is the discharge period of the AC voltage, f is the frequency, and D is the duty cycle. The current is indirectly obtained by measuring the charge across the capacitor and differentiating it with respect to time.…”

Reactive species responsible for the inactivation of feline calicivirus by a two‐dimensional array of integrated coaxial microhollow dielectric barrier discharges in air

“…Alumina was used as the dielectric material to separate and cover the two ultra‐thin internal metal electrode plates. For detailed specifications about the multilayered electrode arrangement, the reader is referred to reference …”

“…The discharge was ignited by a high voltage sinusoidal signal at 20 kHz generated by an AC power source (PVM500). The discharge power was measured using the Lissajous method as described in reference . The voltage was measured by a high‐voltage probe (Tektronix P6015A) and the charge was obtained by measuring voltage across a known capacitor with a general‐purpose passive voltage probe (Tektronix TPP0200).…”

“…In this study, we investigate plasma decontamination of FCV, which is often used as a surrogate for human norovirus responsible for causing acute gastroenteritis, more commonly known as “stomach flu” or “winter vomiting disease.” Hence, this study is of direct importance for the decontamination of food contact surfaces contaminated with food‐borne viruses. We used a kilohertz‐driven array of integrated coaxial microhollow dielectric barrier discharges in air at atmospheric pressure in a flow‐through system . The FCV was used as a biological model to assess the virucidal efficacy of the plasma source as well as to determine the underlying chemistry responsible for virus inactivation.…”

Comparative evaluation of the virucidal effect of remote and direct cold air plasmas with UV‐C

“…The plasma power was measured by the Lissajous method, as described previously. [ 40 ] Applied voltage and voltage across the external capacitor were recorded using a high‐voltage (HV) probe (1,000×, Tektronix P6015A) and a general‐purpose capacitive probe (10×, Tektronix TPP0200), respectively.…”