Study on Argon Plasma Jets at Atmospheric Pressure in Ambient Air Excited by Surface Waves

A novel method to produce strong and effective argon plasma jets in air is reported. By adjusting the structure and setting the location of a copper wire in the quartz tube, an intensive jet composed of two jets about 2.4 cm is produced with microwave power of 50 W. The microwave frequency is 2.45 GHz. Four twisty plasma jets about 2.0 cm for argon discharge are generated in four tubes at incident power of 120 W. A plasma ball of air discharge about 0.5 cm in radii is generated in the tube at the power of 100 W. The simulated distribution of electric field in the tube with a folded copper wire is consistent with the prediction of surface plasmon polaritons. Spectral diagnosis of the plasma jets is also discussed in this paper.