Atmospheric pressure air plasma jet enhancing nitic oxide generation

Abstract

Nitic oxide (NO) usually serves as an anti-microbial factor killing bacteria and fungi without damaging the human cells, inhalation therapy and wound decontamination/healing. We present in this work a modified design of microhollow cathode discharge was used to generate Atmospheric-pressure plasma jets (APPJ) in air to enhance the NO generation. The APPJ system consists of a hollow-needle with 0.5and 0.75mm inner and outer diameters, respectively. The needle is connected to AC high voltage power supply and has a sleeve of an alumina (Al2O3) tube that covers its body except the tip. A brass cap is used to cover the tube nozzle with a central hole of 1 mm diameter and 0.4mm gap between the tip and the cap which is grounded. The plasma-jet discharge breakdown voltage is 950V while the sustained voltage is 450V The electric and spectroscopic characteristics of the generated jet and NO are investigated at different air follow rates, applied voltages and frequencies. The emission spectra indicates the presences of NO spectra and enrichment of the second positive system of the nitrogen molecule. The NO emission intensity increases with the follow rate and the frequency of applied voltage whereas it decreases with the increase of the voltage.