Application of Y-ZrO2 microtubes as dielectric barrier material in a He atmospheric pressure micro-plasma jet

Abstract

This work focused on the application of novel 8% yttria-stabilized Zr2O3 (YSZ) microtubes with an inner diameter of 60 mu m as dielectric material in an atmospheric pressure micro-plasma jet (APPJ). Furthermore, a comparison with quartz microtubes allowed to study the effect of tube material on plasma properties. Optical emission spectroscopy was employed to determine various spectral line ratios including ratios of He lines 667 nm (3(1)D-2(1)P) to 728 nm (3(1)S-2(1)P) which is indicative of electric field strength. The 667/728 nm line ratio in the YSZ microtube was about 2/3 the value in the 60-mu m quartz tube. However, increasing the quartz tube's inner diameter from 60 to 500 mu m decreased the 667/728 nm line ratio 40 times. Additionally, the spatio-temporal evolution of the ionization wave was measured in the YSZ microtube and the velocity of the ionization wave was determined to accelerate from 67 km/s near the powered electrode to 161 km/s near the tube orifice.