STP1066

    Laser Induced Fluorescence and Ionization Techniques for Combustion Diagnostics

    Published: Jan 1990


      Format Pages Price  
    PDF Version (320K) 19 $25   ADD TO CART
    Complete Source PDF (3.0M) 19 $55   ADD TO CART


    Abstract

    Light atomic species such as oxygen atoms (O) and hydrogen atoms (H) are fundamentally important in a wide variety of combustion-related phenomena such as flame ignition, propagation, extinction and in chemical flame reactions. Furthermore, they are difficult to detect by conventional laser based optical methods (laser induced fluorescence) in combustion environments because the necessary resonance excitation wavelengths fall far into the vacuum ultraviolet (vuv) and the requisite tunable laser sources are not generally available. However, recent developments in nonlinear spectroscopic techniques such as multiphoton induced emission (MPE) and multiphoton ionization (MPI) have made direct detection of these light atoms possible. We have utilized a number of laser multiphoton excitation schemes for their detection using tunable lasers in the 190 to 400 nm range. Similar diagnostic techniques were attempted for the detection of carbon (C) and nitrogen (N) atoms in flames. The effects of laser induced photochemical pertubations on species detection in flames were also investigated. These nonlinear spectroscopic techniques have been demonstrated to be very useful in combustion studies but special care needs to be taken with respect to possible perturbations that may result from the use of short-wavelength lasers.

    Keywords:

    atoms, laser-induced fluorescence, multiphoton ionization, optogalvanic, flames, fuel, oxidizer, laser, dye laser, resonance, burner, rate constants, quenching, ignition, luminescence spectroscopy


    Author Information:

    Forch, BE
    Research chemist, research chemist, and research physicist, U.S. Army Ballistic Research Laboratory, Aberdeen Proving Ground, MD

    Morris, JB
    Research chemist, research chemist, and research physicist, U.S. Army Ballistic Research Laboratory, Aberdeen Proving Ground, MD

    Miziolek, AW
    Research chemist, research chemist, and research physicist, U.S. Army Ballistic Research Laboratory, Aberdeen Proving Ground, MD


    Paper ID: STP23479S

    Committee/Subcommittee: E13.06

    DOI: 10.1520/STP23479S


    CrossRef ASTM International is a member of CrossRef.