A Planar Source of Atmospheric-Pressure Plasma Jet
- PDF / 367,287 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 8 Downloads / 245 Views
IED PHYSICS
A Planar Source of Atmospheric-Pressure Plasma Jet O. S. Zhdanovaa, *, V. S. Kuznetsovb, c, V. A. Panarinb, V. S. Skakunb, E. A. Sosninb, c, and V. F. Tarasenkob a
b Institute
Siberian State Medical University, Tomsk, 634050 Russia of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk, 634055 Russia c Tomsk State University, Tomsk, 634050 Russia *e-mail: [email protected] Received February 19, 2016
Abstract—In a single-barrier discharge with voltage sharpening and low gas consumption (up to 1 L/min), plane atmospheric pressure plasma jets with a width of up to 3 cm and length of up to 4 cm in air are formed in the slit geometry of the discharge zone. The energy, temperature, and spectral characteristics of the obtained jets have been measured. The radiation spectrum contains intense maxima corresponding to vibrational transitions of the second positive system of molecular nitrogen N2 (C3Πu → B3Πg) and comparatively weak transition lines of the first positive system of the N2+ ion ( B 2Σu+ → X 2Σ g ). By an example of inactivation of the Staphylococcus aureus culture (strain ATCC 209), it is shown that plasma is a source of chemically active particles providing the inactivation of microorganisms. DOI: 10.1134/S1063780X18010166
INTRODUCTION Sources of atmospheric pressure plasma jets (APPJs) became an object of extensive studies after understanding their applicability in biology, medicine, and machining of surfaces of different materials [1−3]. The plasma flow in different APPJ sources is formed as a rule in the discharge gap (the excitation is implemented by a radio frequency, corona, glow, or dielectric barrier discharge (DBD)) and then is pushed out through a narrow capillary or slit due to the excessive pressure in the discharge zone as compared to the atmospheric pressure [1−12]. Excitation by a glow, corona, or DBD creates nonequilibrium plasma with an average gas temperature from 20 to 400°C and charged particle density typical of weakly ionized gases (no higher than 1011–1012 cm–3) and active particle density of up to 100 ppm. At temperatures close to room temperature, the plasma is called cold atmospheric plasma or nonthermal plasmas [2]. At present, APPJ sources in which helium, argon, and/or their mixtures with nitrogen play the part of a working gas came into common use. Forming an APPJ in nitrogen and air is much more difficult. In this case, there appear more chemically active particles [9], but the plasma flow becomes sensitive to the gas circulation rate and its temperature increases. Therefore, the plasma source cannot be treated as a low-temperature source any longer. It is also important that an extended plasma jet cannot be formed [12].
The glow is formed only in the near-electrode zone and rapidly decays in the free space beyond it. In [13, 14], we proposed and studied a capillary DBD-based APPJ source forming stable flows with a length of up to 4 cm in air and nitrogen at atmospheric pressure. For this purpose, we used a scheme in which the voltage
Data Loading...
