Interferomety of plasma bursts in helium atmospheric-pressure plasma jets

The main objective of this work is to explore the possibility of applying an interferometry technique as an alternative tool for characterization of an atmospheric-pressure plasma jet (APPJ). Thus, the authors imaged plasma discharge of He gas flow in the APPJ using a Michelson interferometer and compared results with schlieren photography. Both cases showed that the plasma discharge followed the He flow in the open atmosphere; however, the plasma discharge also affected the gas flow, indicating a transition from laminar to turbulent flow. The authors believe that the implementation of this new, potentially quantitative, diagnostic tool maybe helpful for understanding plasma phenomena.