In this paper, the absorbed power, power density, and absolute UV emission of a radio-frequency jet working in continuous and pulsed modes are measured. The plasma source is a plasma needle which operates under atmospheric pressure with helium or argon in air. Photographs of the discharges were taken to present the effect of radial contraction of the argon plasma for the highest power densities investigated. The contraction is explained by the electron-ion- dissociative-recombination-dominated losses in the argon case.
- Atmospheric-pressure plasma (APP) jet
- radial contraction