Non-local thermodynamic equilibrium in laser sustained plasmas

Conference · Wed Jul 01 04:00:00 EDT 1992

OSTI ID:7155107

Zerkle, D K; Krier, H ^[1]

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1. Illinois, University, Urbana (United States)

An argon laser sustained plasma (LSP) at atmospheric pressure has been studied spectroscopically, and the existence of a nonlocal thermodynamic equilibrium state has been determined. The spectroscopic data consist of argon neutral and ion line emissions used to spatially resolve electronic energy level population densities in each plasma species. A hydrogen seed is added to the argon flow for the purpose of determining the electron number density by Stark broadening analysis of the Balmer series alpha line. Electron and heavy particle kinetic temperatures are calculated through the use of an appropriate nonequilibrium model. The dominant nonequilibrium effect in this plasma is kinetic nonequilibrium where the electron kinetic temperature can be more than twice the heavy particle kinetic temperature in high laser power flux regions. Typical electron and heavy particle kinetic temperatures are 14,000 K and 8000 K, respectively. Electron number density ranges from 6 x 10 exp 16/cu cm to 2.1 x 10 exp 17/cu cm. 31 refs.

• OSTI ID: 7155107
• Report Number(s): AIAA-Paper--92-2991; CONF-9207111--
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700320 -- Plasma Diagnostic Techniques & Instrumentation-- (1992-)
700330* -- Plasma Kinetics
Transport
& Impurities-- (1992-)
ATMOSPHERIC PRESSURE
BALMER LINES
ELECTRON DENSITY
EMISSION SPECTRA
EQUILIBRIUM
LASER-PRODUCED PLASMA
LINE WIDTHS
LTE
PLASMA
PROPULSION SYSTEMS
SPECTRA
TEMPERATURE MEASUREMENT