Application of saturation spectroscopy to the measurement of C_2, ^3Π_u concentrations in oxy-acetylene flames

Abstract

The technique of saturation spectroscopy is applied to measure the concentration of C2 in the 3Πu state in oxyacetylene flames. The two level model is further developed and extended for use in intensity regions slightly lower than that required to saturate the resonances completely. As a result, it has proved feasible to measure both the C2 number density in the 3Πu state of ~1016/cm3 and an excited electronic state lifetime of ~10−12 sec, both of which depend only on the Einstein A coefficient. The experimental setup is described in detail, and possible extensions of the technique to other atomic and molecular systems are discussed.