Plasma Propagation Speed and Electron Temperature in Slow Electron Energy Non-thermal Atmospheric Pressure Indirect-Plasma Jet

Space- and time-resolved discharge-images from a nonthermal atmospheric-pressure indirect-plasma jet have been observed using a high-speed single-frame camera to investigate the electron temperature. The propagation velocity of the indirect Ar-plasma along the plasma column has been shown to be on the order of 10⁴ m/s, and that corresponds to an ion acoustic velocity on the order of 10² m/s. Plasma has been generated by varying input discharge voltages from 2.0 to 4.0 kV at a driving frequency of 40 kHz. Particularly, the average electron temperature in slow electron energy nonthermal atmospheric-pressure indirect-plasma jet has been found to be about 0.3 eV.