Two-dimensional temperature measurements in particle loaded technical flames by filtered Rayleigh scattering

Filtered Rayleigh scattering (FRS) is applied to determine two-dimensional temperature distributions in a hexamethyldisiloxane loaded propane/air flame intended for combustion chemical vapor deposition processes. An iodine cell as a molecular filter suppresses background scattering, e.g., by particles, while the wings of the spectrally broadened Rayleigh scattering can pass this filter. A frequency-doubled Nd:YAG laser is tuned to a strong absorption line of iodine. The gas temperature is deduced from the transmitted Rayleigh scattering signal. Since FRS also depends on molecule-specific scattering cross sections, the local gas composition of majority species is measured using the Raman scattering technique. Limits and restrictions are discussed. (C) 2014 Optical Society of America