Evolution of Bullets in Helium Atmospheric Pressure Plasma Jet

Plasma medicine field development triggered intense research efforts to understand the physics and chemistry of atmospheric pressure plasma jets. High-speed photography offers unique information on plasma continuity and upon specific structures with very short life time, typically in the nanosecond range. Using this technique, we have shown that the helium plasma jet contains two distinct types of bullets with respect to the spatial distribution of emitted light, homogeneous and nonhomogeneous ones.