Development of a high-efficient and uniform microwave-induced atmospheric pressure linear plasma jet source based on a square coaxial structure

Abstract

A microwave-induced atmospheric pressure linear plasma jet source at 2.45 GHz based on a square coaxial structure was proposed. The device was capable of generating a plasma jet by exciting argon gas with 50 W microwave incident power. By increasing the microwave power or gas flow rate, the width and height of the resulting linear plasma jet gradually expanded. Experimental results showed that a linear plasma jet with a width of 30 mm and a height of 8 mm was produced with 200 W microwave incident power and 40 l/min gas flow rate. Optical emission spectra measurements at different positions showed that the produced linear plasma has good homogeneity. The electron density of the generated linear plasma reached 1015 cm−3. The energy utilization of this plasma source was more than 90%. This portable plasma device offers great potential for linear plasma applications in areas such as food processing and environmental treatment.