Flame and Trident Plasma Emissions of Single Rectangular-Shaped Atmospheric Pressure Plasma Jet

A single atmospheric pressure plasma jet device using a rectangular tube has been proposed for generating the intense glow plasmas. Two plasma regimes were found to exist in the same plasma structure under changes of gas flow rate and applied voltage conditions: the flame plasma regime and the trident plasma regime. When the gas flow rate and applied voltage were at low values, the flame glow plasma was produced, whereas the trident glow plasma was produced when the gas flow rate and applied voltage were at high values. Under identical electrical driving and gas conditions in each plasma regimes, the optical intensity of the trident plasma regime was approximately two times larger than the flame plasma regime. This highly energetic trident plasma jet is useful in developing novel applications requiring strong atmospheric pressure discharge processes by using very simplified structures, easy fabrication, potable and light weight, wide area, patterning generation, and low manufacturing and maintenance cost compared with the vacuum plasmas.