Spatial correlation between emitting species and plasma bullet propagation in low temperature plasma jets

Summary form only given. Low temperature plasma jets are being extensively used in plasma processing including biomedical applications¹. This is due to their ability of launching controllable plasma plumes in atmospheric pressure air, not confined by electrodes. These plasma jets are in fact vehicles transporting reactive chemical species to a remote substrate in the form of the so-called “Plasma Bullets”². Plasma bullets are ionization waves able to travel at very high speeds. Therefore, since plasma jets are in fact series of propagating plasma packets/bullets, the spatial distribution of the chemical species is a dynamic quantity that varies with the spatial location of the plasma bullet. This is due to substantial changes in size and content that the plasma bullet undergoes as it mixes with the surrounding air along its propagation path.In this paper, the spatial distributions of the emitting species emanating from the plasma plume of our plasma pencil are measured by Optical Emission Spectroscopy and correlated with the position and physical characteristics of the plasma bullet. In this experiment new detailed data of the relative density of species such as N2+, OH, N2, He and atomic oxygen within a traveling bullet through the air are measured by ICCD camera connected to an imaging spectrometer. Spatially resolved emitted light intensity of each bullet is also measured in order to quantify the results.