A cold plasma cross made of three bullet-like plasma plumes

In contrast to other atmospheric pressure plasma jets, two perpendicular jet-like plasmas generated in ambient air by a special designed plasma device are reported. High-speed photographs taken by an ICCD camera with exposure time of 2 ns show that the horizontal part of the plasma is actually ignited by the vertical part of the plasma. Both the vertical and horizontal parts of the plasma are in fact a small bullet like volume of plasma traveling along different directions at high velocities. The horizontal plasma volume velocity is about half of the vertical plasma volume velocity at the same instant.