UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2024-11-21 20:17
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Conference: Bucharest University Faculty of Physics 2008 Meeting


Section: Optics, Spectroscopy, Plasma and Lasers


Title:
Electrical and optical characterization of a small size cold plasma jet source


Authors:
M. D. Ionita1, I. Luciu1, E. R. Ionita1, G. Dinescu1, M. Bazavan2, I. Iova2


Affiliation:
1National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Street, Magurele MG-36, RO 77125, Bucharest, Romania

2 University of Bucharest, Faculty of Physics, 76900, Bucharest-Măgurele, P.O. Box MG-11


E-mail
dinescug@infim.ro


Keywords:
cold plasma jet, radiofrequency plasmas, plasma sources, electrical measurements


Abstract:
In the last period have been reported many applications of cold plasma jet sources in atmosphere operation, with temperature of gas in the range 30-50 Celsius degree. The main application of cold plasma jets consists in modification of polymer surface properties, like: wetability, roughness, adhesion, etc. The fundamental processes which take place at interface between these cold atmospheric jets and the surface exposed are not well know. For this reason we have performed imaging, spectral and electrical measurements of a small size (8 mm diameter) plasma jet source used for modification of wetability of polymer surfaces. The plasma jet source, used here, consist in one small electrode (3mm) faced with other one which is drilled and have a hole of 1 mm. The gas is introduced in this gap. The first electrode is wired to RF power generator at 13.56 MHz through impedance matching network. The second electrode is connected to ground. A quartz tube is used for isolation and cover around the RF electrode. In the gap (2-5 mm) a capacitive discharge is generated by applying the RF power (range8-25 W). Plasma expands out from the hole as a jet. The spectra emitted by the jet were recorded by an Optical Multichannel Analyzer. They show the presence of nitrogen bands, NO2 continuum and NO and OH bands. The electrical characteristics show the breakdown point and the I-V curve after breakdown. The system presents an hysteretic behavior, the ignition curve an the extinction curves being different. It allows the operation of the source on the extinction curve, with lower power values, leading to cold plasmas.