| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:26 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2004 Meeting
Section: Optics, Spectroscopy, Plasma and Lasers
Title:
Space distribution of the nitrogen emission bands in a parallel plate radiofrequency discharge at intermediate pressures
Authors:
I. Ciobanu, G. Vlad, R. Ionita, G. Dinescu, M. Bazavan*, I. Iova*
Affiliation:
National Institute for Laser, Plasma and Radiation Physics
PO Box MG 16-Magurele, Bucharest, 77125 Romania, dinescug@infim.ro
*Faculty of Physics, University of Bucharest, Magurele, Romania
E-mail
dinescug@infim.ro
Keywords:
radiofrequency discharge, nitrogen, emission spectroscopy
Abstract:
Possible new applications of high pressure, non-equilibrium plasmas strongly encourage the research devoted to the extension of the operation range of plasma sources at high pressure. In the case of radiofrequency discharges several operation regimes can be encountered, as example large volume discharges - which can be dominated by volume processes (ƒÑ regime) or electrodic processes (ƒ× regime) - or constricted filamentary discharge (arc, spark regime). The operating regime modifies according to the current through the discharge and with the gas pressure. It depends also on the gas nature.
The filamentary regime, which is favored at high pressures, has to be avoided in order to obtain uniform glow discharges at high pressure. In this work results concerning the distribution of the nitrogen bands emission in the interelectrodic space, which give information about the discharge regime, are presented. The spectra are recorded at various pressures up to atmospheric. From the measurements the plasma sheaths were visualized and information on the behavior of the electron temperature across the discharge gap was obtained by taking into account the relative intensities of the Second Positive and the First Positive Spectral Systems. In addition, the dependence of the discharge transition from uniform to filamentary regime upon pressure, at various radiofrequency powers was investigated, which establish the limits of discharge operation as a cuasi-uniform glow.
|
|
|
|