Multiphoton Photochemical and Collisional Effects during Oxygen Atom Flame Detection.
Final technical rept.,
ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
Pagination or Media Count:
A NdYAG pumped dye laser system was used to two-photon excite oxygen atoms at 225.6 nm in an atmospheric pressure CH4N2oN2 flame. Subsequent emission at 844.7 nm from the directly populated state, as well as a stronger emission at 777.5 nm due to the O3p 3p to 3p 5p collisional energy transfer process, was monitored. Two-photon resonant oxygen atom and hydrogen atom 656.3 nm emissions were also observed in the absence of a flame. Closer examination revealed that the tightly focussed probe beam was producing these atoms by promoting multiphoton photolysis of the oxidizer, as well as fuel molecules. Thus, this type of laser diagnostic probe is potentially quite intrusive depending on the combustion region that is probed, as well as the laser energies used.
- Radiation and Nuclear Chemistry