Study of a thermal plasma jet by means of a Langmuir probe

L. PREVOSTO; H. KELLY; B. MANCINELLI

Buenos Aires

Congreso; XII Reunión de fluidos y sus aplicaciones (FLUIDOS 2012); 2012

UBA

Langmuir probe measurements in an atmospheric pressure direct current (dc) plasma jet are reported. Sweeping probes were used. The experiment was carried out using a dc non?transferred arc torch with a rod?type cathode and an anode of 5 mm diameter. The torch was operated at a nominal power level of 15 kW with a nitrogen flow rate of 25 Nl min-1. A flat ion saturation region was found in the current?voltage curve of the probe. The ion saturation current to a cylindrical probe in a high?pressure non local thermal equilibrium (LTE) plasma was modeled. Thermal effects and ionization/recombination processes inside the probe perturbed region were taken into account. Averaged radial profiles of the electron and heavy particle temperatures as well as the electron density were obtained. Large deviations from kinetic equilibrium were found throughout the plasma jet.