Gas temperature and electron density profiles in an argon dc microdischarge measured by optical emission spectroscopy

Sergey G. Belostotskiy , Tola Ouk , Vincent M. Donnelly , Demetre J. Economou , Nader Sadeghi (1)

1 LAME-LIPhy - LAsers, Molécules et Environnement

Optical emisssion spectroscopy was employed to study a high pressure (100 s of Torr), slot-type (600 μm interelectrode gap), argon dc microdischarge, with added traces of nitrogen. Spatially resolved gas temperature profiles were obtained by analyzing rovibrational bands of the N2 first positive system. The gas temperature peaked near the cathode and increased with current. The contribution of Stark broadening to the hydrogen Hβ emission lineshape was used to extract the electron density. The axial distribution of electron density as well as visual observation revealed that the microdischarge positive column was highly constricted. The electron density near the sheath edge increased with both pressure and current.

Mots clés: argon; discharges (electric); nitrogen; plasma boundary layers; plasma density; plasma diagnostics; plasma temperature; positive column; spectral line broadening; Stark effect; Optical measurements; Emission absorption and scattering of electromagnetic radiation; Plasma-material interactions; boundary layer effects; Plasma sheaths; Electric discharges

Domaines: Optique [physics.optics]; Physique des plasmas [physics.plasm-ph]

Sergey G. Belostotskiy, Tola Ouk, Vincent M. Donnelly, Demetre J. Economou, Nader Sadeghi. Gas temperature and electron density profiles in an argon dc microdischarge measured by optical emission spectroscopy. Journal of Applied Physics, 2010, 107, pp.3305. ⟨10.1063/1.3318498⟩. ⟨hal-01005905⟩