Laser-Based Ignition of H2/O2 and D2/O2 Premixed Gases Near 243 nm: The First Report of a Deuterium Isotope Wavelength Effect in Laser Ignition
Abstract
We investigated the use of a tunable laser system which operates in the ultraviolet (uv) to ignite premixed reactive gaseous flows of H2/O2 and D2/ O2 at atmospheric pressure. The amount of incident laser energy (ILE) required to ignite the premixed flows as a function of laser excitation wavelength show two distinct minima. The spectral position of these minima correspond exactly to the location of the resonance, two-photon exictation wavelengths of atomic hydrogen and deuterium at 243.07 and 243.00 nm respectively. The relative spacing between these minima at the energy level of the 1S-2S two-photon excited transition is 22/cm which is in excellent agreement with the known value for H-D deuterium isotope shift (22.4/cm). We believe that this is both the first report of a sensitive wavelength dependence on the laser energy required to ignite these mixtures through resonant multiphoton excitation of H and D atoms (produced from H2 and D2 photolysis) and the first report of a deuterium isotope-wavelength-effect in laser ignition. Measurement of the ILE required for ignition vs. equivalence ratio (phi) shows that the most efficient ignition occurred with approx. 0.55 mJ ILE at phi=0.7 in the fuel lean region.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1991
- Accession Number
- ADA243180
Entities
People
- Andrzej W. Miziolek
- Brad E. Forch
Organizations
- Ballistic Research Laboratory