Characterization of atmospheric pressure helium plasma jet driven by microsecond pulse

In this paper, a microsecond pulse driven helium plasma jet was well characterized by different electrode configurations and discharge parameters. The influence of dielectric material diameter (3 mm, 5 mm and 8 mm), different electrode configuration and frequencies on the discharge properties and optical emissions were studied. The results showed that the length of plasma jet plume reduced when dielectric material diameter was increased. The breakdown voltage and discharge current were the smallest with a diameter of 8 mm, while the intensities of N₂, N₂ ⁺, O and OH species reached their peaks. The discharge current, consume power and energy were the highest when the diameter was 5 mm. What's more, larger discharge current, consume power and emission intensity were observed with sharp tip needle electrode configuration. Higher pulse repetition frequency led to lower breakdown voltage and longer length.