DEPARTURES FROM EQUILIBRIUM NEAR THE COPPER ANODE OF AN ARGON TRANSFERRED ARC

Citation
M. Bouaziz et al., DEPARTURES FROM EQUILIBRIUM NEAR THE COPPER ANODE OF AN ARGON TRANSFERRED ARC, Journal of applied physics, 84(8), 1998, pp. 4128-4136
Citations number
48
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Applied
Journal title
ISSN journal
0021-8979
Volume
84
Issue
8
Year of publication
1998
Pages
4128 - 4136
Database
ISI
SICI code
0021-8979(1998)84:8<4128:DFENTC>2.0.ZU;2-X
Abstract
Spectroscopic measurements on an argon transferred arc have been perfo rmed in the plasma region just above the copper anode, by means of the arc interruption technique. This technique, based on the recording of the transient evolution of total spectral line intensities, allows on e to determine the difference T-e - T-h between the electron temperatu re and the heavy particle temperature, existing in steady state. Durin g the extinction of the low arc current, the evolution of some argon l ines presents first a sudden increase before a slow general decrease, whereas the evolution of copper lines shows first a very fast decrease followed by a slow extinction. These phenomena have been interpreted considering that argon excited-state populations are strongly correlat ed with ions and electrons (Saha equilibrium) whereas the copper excit ed-state populations are correlated with the ground-state density (Bol tzmann equilibrium). The difference T-e-T-h deduced from both kinds of measurements varies between 500 and 800 K. (C) 1998 American Institut e of Physics. [S0021-8979(98)08019-0].