Accession Number : ADA329579

Title :   Nonlinear Laser Diagnostics for Combustion and Plasma Processes.

Descriptive Note : Final rept. 15 Apr 94-14 Apr 97,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA

Personal Author(s) : Faris, Gregory W. ; Huestis, David L. ; Jeffries, Jay B.

PDF Url : ADA329579

Report Date : 11 JUN 1997

Pagination or Media Count : 37

Abstract : Significant milestones for quantitative laser-based diagnostics of reacting flows were reached on two separate tasks: (1) the extension of laser-based diagnostics to shorter vacuum ultraviolet (vuv) wavelengths and (2) the development of amplified spontaneous emission (ASE) diagnostics for light atoms. For the first task, phase-matching was applied to produce significant increases in vuv laser intensities, producing over 5 mu J at Lyman alpha (121.6 nm) in a mixture of krypton and argon. Factors affecting the long-term stability of vuv powers were studied. The diagnostic potential of two-photon excited ASE of atomic hydrogen and oxygen was explored in a variety of low-pressure flames. Direct ASE gain measurements gave oxygen concentrations. A model of the ASE signal was developed, and a new understanding of both ASE and laser-induced fluorescence of two-photon excited atoms emerged from this model.

Descriptors :   *PLASMAS(PHYSICS), *LASER APPLICATIONS, *VACUUM ULTRAVIOLET RADIATION, *PLASMA DIAGNOSTICS, EMISSION, MEASUREMENT, LASER INDUCED FLUORESCENCE, INTENSITY, LOW PRESSURE, ATOMS, LONG RANGE(TIME), HYDROGEN, MIXTURES, OXYGEN, COMBUSTION, NONLINEAR SYSTEMS, GAIN, DIAGNOSIS(GENERAL), PHOTONS, FLAMES, AMPLIFICATION, ARGON, CONCENTRATION(CHEMISTRY), ATOMIC STRUCTURE, KRYPTON.

Subject Categories : Lasers and Masers
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE