High-Speed Visualization of Filament Instabilities and Self-Organization Effect in RF Argon Plasma Jet at Atmospheric Pressure

An RF argon plasma jet has been explored using high-speed camera imaging at 10000 frames/s. Small variations of gas flow and/or RF power lead to instabilities of the filament movement. Two types of instabilities have been observed depending on the interrelated azimuthal velocities of filaments. In the case of antiparallel filament velocities, one filament is collapsing and fuses with the other filament, while the collapsing filament exhibits a striated structure. In the case of parallel velocities, both filaments establish a symmetric configuration and rotate with constant velocity in the jet. Spatially and temporally resolved features are visualized with a time-colored stroboscopic image.