Determination of gas-temperature and velocity profiles in an argon thermal-plasma jet by laser-light scattering

Journal Article · Mon Mar 01 04:00:00 EST 1993 · Physical Review E; (United States)

DOI:https://doi.org/10.1103/PhysRevE.47.1996· OSTI ID:7057822

Snyder, S C; Reynolds, L D; Lassahn, G D; Fincke, J R; Shaw, Jr, C B ^[1]; Kearney, R J ^[2]

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1. Idaho National Engineering Laboratory, EG G Idaho, Inc., P.O. Box 1625, Idaho Falls, Idaho 83415 (United States)
2. Department of Physics, University of Idaho, Moscow, Idaho 83843 (United States)

Gas-temperature and velocity profiles at the exit plane of a thermal argon plasma torch have been determined directly from a high-resolution Doppler-shifted line-shape analysis of laser light scattered by the plasma. Peak temperature and velocity values observed were 13 350 K[plus minus]7% and 1100 m s[sup [minus]1][plus minus]3%. Velocities as low as 45 m s[sup [minus]1][plus minus]45% were measured in the fringe of the jet. An injection-seeded pulsed neodymium-doped yttrium aluminum garnet laser was used as the laser source and the scattered laser light was analyzed with a scanning tandem Fabry-Perot interferometer. Temperature data obtained from laser scattering are compared with values obtained from emission spectroscopy and show a severe departure from local thermodynamic equilibrium (LTE) in the outer regions of the jet. Gas temperatures were observed to increase as the torch operating current increased from 300 to 500 A, but remained constant as the operating current increased to 900 A. However, electron temperatures and densities continued to increase with operating current. This suggests that increasing the electrical power drives the plasma away from LTE. Measured temperature and velocity profiles were found to be nearly parabolic.

• DOE Contract Number: AC07-76ID01570
• OSTI ID: 7057822
• Journal Information: Physical Review E; (United States), Journal Name: Physical Review E; (United States) Vol. 47:3; ISSN PLEEE8; ISSN 1063-651X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700320* -- Plasma Diagnostic Techniques & Instrumentation-- (1992-)
ARGON
DOPPLER EFFECT
ELEMENTS
EQUILIBRIUM
FLUIDS
GASES
LASERS
LIGHT SCATTERING
LINE WIDTHS
NONMETALS
PLASMA
PLASMA DIAGNOSTICS
PLASMA JETS
RARE GASES
SCATTERING
TEMPERATURE DISTRIBUTION
THERMAL EQUILIBRIUM
VELOCITY