Spectroscopic diagnostics of electron temperature and energy-conversion efficiency of laser-sustained plasma in flowing argon. Report for 1 September 1987-8 August 1988

Technical Report · Thu Aug 25 00:00:00 EDT 1988

OSTI ID:5762486

Mazumder, J; Krier, H; Chen, X

Laser-sustained plasmas are often formed during laser materials interaction. The University's 10-kW CW CO/sub 2/ laser was used to study argon plasmas for the application to laser supported propulsion and laser-materials processing. The spectroscopic diagnostic method was applied to study laser-sustained plasmas in 1 atmosphere pure argon gas flow with an f/7 on-axis laser-focusing scheme. High-flow speeds of 2 to 10 m/sec are achieved. Plasma electron-temperature distributions are determined from the 415.8-nm Ar I line and its adjacent continuum intensities. Plasma core temperatures as high as 20,000 K are reported. The total absorption of the incident laser power and the radiation loss by the plasma are calculated from the temperature distribution. Results indicated that up to 86% of the incident laser power can be absorbed and nearly 60% of the incident laser power can be retained by the flowing argon gas to provide thrust. Further research is called for in the laser induced fluorescence (LIF) technique for diagnostics of the downstream mixing zone and the plasma outer region. Experiments over a wider range of operating conditions, as well as multiple plasma testings, are required to find the optimum operating scheme.

• Research Organization: Illinois Univ., Urbana, IL (USA). Dept. of Mechanical and Industrial Engineering
• OSTI ID: 5762486
• Report Number(s): AD-A-207054/8/XAB; UILU-ENG-88-4014
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ARGON
LASER-PRODUCED PLASMA
ENERGY CONVERSION
ELECTRON TEMPERATURE
ABSORPTION
DISTRIBUTION
EFFICIENCY
ELECTRONS
FLUORESCENCE
GAS FLOW
INTERACTIONS
LASER MATERIALS
LOSSES
MIXING
POWER
PROCESSING
PROGRESS REPORT
PROPULSION
SPECTROSCOPY
VELOCITY
CONVERSION
DOCUMENT TYPES
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
FLUID FLOW
FLUIDS
GASES
LEPTONS
LUMINESCENCE
MATERIALS
NONMETALS
PLASMA
RARE GASES
640410* - Fluid Physics- General Fluid Dynamics