Plasma non-equilibrium of the DC normal glow discharges in atmospheric pressure atomic and molecular gases
Gas Discharge Physics Laboratory, Stepanov Institute of Physics of
the NAS of Belarus, ave.
Nezavisimostsi 68, 220072
Received: 7 June 2012
Received in final form: 2 August 2012
Published online: 4 October 2012
Electrical and spectroscopic results of comprehensive investigations of atmospheric pressure glow discharges in helium, argon, nitrogen and air in a large current range are presented. Our attention in these investigations is mainly focused on the characterization of positive column plasmas at discharge gap of 10 mm. It was shown that helium, nitrogen and air positive columns transform from diffuse to constricted mode when discharge current increases. In argon discharge, it is constricted in the whole range of investigated currents. Reduced electric field, gas temperature, average electron energy and electron concentration were determined. The positive column plasmas of all the atmospheric pressure glow discharges studied are non-equilibrium and weakly ionized. Plasma non-equilibrium degree in atomic gases of helium and argon is essentially higher than in molecular nitrogen and air. For all gases, plasma non-equilibrium degree in a positive column decreases with discharge current increase.
Key words: Plasma Physics
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2012