Acceleration of Plasma Bullets by Grooved Dielectric Rod

In this work, we studied hollow cylindrical plasma bullets propagating along the grooved glass rod in a single electrode configuration. The plasma source was a cylindrical shell consisted of two coaxial glass cylinders. The surface of the inner cylinder was structured by creating grooves on its surface to investigate the plasma bullet acceleration through the traveling shell. The corresponding plasma jet was driven by a 6.2-kHz sinusoidal waveform using helium gas. Optical and electrical characteristics proved that the plasma jet was working in a stable bullet mode. The propagation speed of the hollow cylindrical bullet was evaluated along with the downstream of the jet axis inside and outside of the plasma carrier shell. The results showed that the charge associated with the bullets and corresponding root-mean-square (rms) value of the alternative current (ac) electric field were increased by creating the grooves on the path of the bullets. It was observed that the radiation intensity of the plasma was increased around each groove, too. The structured inner cylinder revealed that the dielectric properties play an essential rule in the plasma bullet propagation through tubes.