87 research outputs found
Cathode fall characteristics in a dc atmospheric pressure glow discharge
Copyright 2003 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the authors and the American Institute of Physics. This article appeared in the Journal of Applied Physics and may be found at: http://link.aip.org/link/?JAPIAU/94/5504/1Atmospheric pressure glow discharges are attractive for a wide range of material-processing
applications largely due to their operation flexibility afforded by removal of the vacuum system.
These relatively new atmospheric plasmas are nonequilibrium plasmas with gas temperature around
100 °C and electron temperature in the 1–10 eV range. Their appearance is characteristically diffuse
and uniform, and their temporal features are repetitive and stable. Of the reported numerical studies
of atmospheric glow discharges, most are based on the hydrodynamic approximation in which
electrons are assumed to be in equilibrium with the local electric field. Spectroscopic and electrical
measurements suggest however that the cathode fall region is fundamentally nonequilibrium. To this
end we consider a hybrid model that treats the cathode fall region kinetically but retains a
hydrodynamic description for the region between the thin cathode fall layer and the anode. Using
this hybrid model, a helium discharge system excited at dc is studied numerically for a very wide
current density range that spans from Townsend dark discharge, through normal glow discharge, to
abnormal glow discharge. Numerical results confirm many distinct characteristics of glow
discharges and compare well with that of low-pressure glow discharges. Generic relationships, such
as that between the electric field and the current density, are also established and are in good
agreement with experimental data. This hybrid model is simple and insightful as a theoretical tool
for atmospheric pressure glow discharges
Comparison of the AC barrier corona with DC positive and negative coronas and barrier discharge
Role of the near-electrode regions in the formation of the volume discharge heterogeneity in nitrogen in the pin-to-plane configuration
Alternating nonsteady gas-discharge modes in an atmospheric-pressure air flow blown through a point-plane gap
Increase of electric field on streamer/surfaces contact area with using external electrode
Effect of the speed of the flat substrate movement on the air plasma jet transversal spreading at its impinging the surface
- …