Atmospheric pressure plasma jet in Ar and Ar/H2O mixtures: Optical emission spectroscopy and temperature measurements

Abstract

An atmospheric pressure plasma jet generated in Ar/water vapor mixtures has been investigated and the effect of water content on plasma properties has been studied. Plasma generated in Ar/water ͑0.05%͒ mixture shows higher intensity of OH radicals in emission spectra than pure argon alone. Plasma density has been estimated from current measurement and is in order of 1.5ϫ 10 13 cm −3 . Electron temperature has been estimated as 0.97 eV in pure Ar and it decreases with an increase in water content in plasma. The gas temperature has been determined by fitting of the experimental spectra and using the Boltzmann plot method. The gas temperature increases with the addition of water to feed gas from 620 K in pure Ar up to 1130 K for 0.76% H 2 O.

Surface modification of polymeric materials by cold atmospheric plasma jet

“…The method commonly employed for obtaining the discharge power is based on the charge-voltage Lissajous figure. The area of the closed Q-V loop for one period of the applied voltage is equal to the energy dissipated per one cycle [11,15]. The mean discharge power is then simply the energy per cycle multiplied by the working frequency [27].…”

“…The plasma plume length can extend up to several centimeters and can be adjusted by an electric field, a gas flow or a pressure gradient [8,9]. The interaction between the plasma plume and the surrounding atmosphere gives rise to different reactive species that may not be present in the discharge region [10,11]. The gas temperature of plasma jets was estimated by various diagnostic methods [12,13] showing that if jet operation conditions were properly chosen the gas temperature at the tip of the plasma plume could be quite low (around room temperature).…”

OH radicals distribution in an Ar-H2O atmospheric plasma jet

“…The details of the techniques used for T g determination by the OH(A-X) v 00 -v 00 ¼ 0-0 emission and their drawbacks can be found elsewhere. 6,12 As shown in Fig. 1, the Sirah Cobra-Stretch dye laser (Rhodamine 590 as the dye) equipped with second harmonic generation unit and pumped by a pulsed Nd:YAG laser was utilized to excite the ground-state OH radicals X 2 P, v 00 ¼ 0 to the A 2 P þ , v 0 ¼ 1 by three excitation transitions, namely, P 2 (6), P 1 (4), and P 2 (3), all at around 283 nm.…”

“…The influence of water admixture on the plasma conditions has already been studied in the past. [4][5][6] Most of these studies, however, are limited by the optical emission spectroscopy which gives information about excited particles only. Optical emission spectroscopy concerns only the excited species which have quite low concentrations compared to their ground states.…”

Optical Emission and Mass Spectra Observations during Hydrogen Combustion in Atmospheric Pressure Microwave Plasma

“…In addition, hydrogen and oxygen radicals are easily generated by high energy electron and ion impacts in the plasma. These radicals play an important role in hydrogen oxidation in gas phase reactions [4][5][6][7]. Therefore, it is expected that highly effective oxidation without precious metals can be developed using atmospheric pressure plasma.…”