Abstract

Quantitative fluorometry of transient combustion species is complicated by the need for information on the composition and quenching rates of the entire system. Saturated fluorometry is one approach to this problem. An alternative, nonsaturating fluorometric method will be illustrated for OH and NH₂ at 1 atm. Projections of sensitivity at elevated pressures will be derived from this data. The measurement technique utilizes low power (nanojoule) picosecond pulses at megahertz repetition rates to achieve a quantitative measure of species concentration that is independent of quenching environment. Direct measurement of quenching rates as fast as 2 × 10¹⁰/s are also possible with the instrumentation developed. The technique involves a noncommercial narrow gated photon counting detection system which is synchronous with a cavity dumped, synch-pumped dye laser. These high repetition rate methods have not previously been applied to the field of combustion diagnostics.

© 1986 Optical Society of America