Optical Emission Spectroscopy of Glow, Townsend-like and Radiofrequency DBDs in an Ar/NH \textsubscript3 Mixture

International audienceThree homogeneous DBD modes have been observed in argon ammonia Penning mixture. The transition from glow to Townsend-like to radiofrequency modes happens when the frequency increases from 50 kHz and 9.6 MHz. The aim of this paper is to characterize these modes based on the study of optical emission spectra. The transition from glow mode to Townsend-like mode is characterized by stronger argon emissions associated to higher energetic electrons. The radio-frequency mode is characterized by a continuum in the UV-vis range. This continuum is attributed to bremsstrahlung emission. Its presence is explained by a high density of less energetic electrons which is consistent with a decrease of argon emissions and an increase of the NH 336 nm system associated with electrons of low energy. \textcopyright 2015 IOP Publishing Ltd

Numerical Simulation of Back Discharge: Influence of Pinhole Geometry on the Regime Transitions

International audienceThis paper presents numerical simulation of back discharge activity that is modelled at a pinhole in a dielectric layer on plane anode. First, for a given pinhole geometry, the transitions between back discharge regimes have been depicted as a mode diagram. Then, we have studied the influence of the dielectric layer thickness on the regime transitions. We have shown that increase in the layer thickness (within range of 0.02\textendash0.2 mm) promotes the back discharge development. Finally, we have studied the influence of `crater configuration'. We have shown that `crater shape' favours the back discharge ignition, whereas limits the resulting discharge development

Numerical Simulation of Back Discharge Ignition

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