Michel Delhaye

Use of multichannel pulsed Raman spectroscopy as a diagnostic technique in flames

Abstract The advantages of multichannel pulsed Raman spectroscopy as a diagnostic technique in gas-phase combustion systems are discussed. With a single-laser shot excitation of 20 nsec, all the major species have been simultaneously detected at different parts of flames. We show that the combination of two detection devices will further allow to determine the temperature and the concentration of the species. Postflame regions have been analyzed in lean, stoichiometric, and rich normal flames, whereas resolved spatial investigations have been achieved in two-stage diethylether-air flames stabilized in flat-flame burners.

Rapid and Ultra Rapid Raman Spectroscopy

An electromechanically scanned monochromator is used for rapid recording of Raman spectra from gases and liquids. This system has demonstrated its usefulness in applications to Raman spectroscopy of time-evolving samples. The limitations of the electromechanically scanned system are discussed and a new electro-optic system is described that utilizes an image intensifier and television camera tube to simultaneously record spectral information in a large number of channels. Results with the electro-optic systems are presented.