Characterization of RF-driven atmospheric pressure plasma micro-jet plume

Authors

• Davood Hassanpour ¹
• Sayyed-Jalal Pestehe * ¹

• Advanced Plasma Laboratory, Faculty of Physics, University of Tabriz, Tabriz, Iran

Abstract

The plasma parameters of an RF-driven plasma microjet in different applied RF powers, different positions from the outlet nozzle, and various argon flow rates are investigated. A double Langmuir probe is designed and constructed, then, the electron temperature, ion density, and saturation currents along the microjet axis at different positions such as top, mid, end and out of the microjet are measured. To avoid the collision, sparking, and corrosion effects, in high pressure plasmas, on the characteristic curve, the double Langmuir probe was reciprocated linearly perpendicular to the plasma jet with a frequency of 20 Hz. The four frequently used methods of the direct fitting of the theoretically obtained formula, double slope, turning point or Dote, and cutting or intercept method are explained and used to determine the electron excitation temperature from the experimental data and shown that they lead to similar results, so, the averaged value of these results used in the evaluations of plasma densities. The plasma number density and electron temperature were measured using DLP in the jet at different axial locations. The results for the electron excitation temperature from the DLP is compared with that of obtained from the emission spectrum of the plasma jet. It has been shown that the averaged electron excitation temperature obtained using optical emission spectroscopy (1.58eV) is within the 25% of that measured by the double Langmuir probe which is same as the early reported value by other researches.

Keywords

• Optical emission spectroscopy
• Atmospheric pressure cold plasma microjet
• Electron temperature
• Langmuir double probe
• RF microjet