The primary objective of the proposed research is to investigate the use of light scattering for the measurement of instantaneous temperatures in rapid thermal reactors. Rayleigh light scattering systems have been used for measurement of temperature and concentration in combustion studies previously. This non-invasive optical technique measures the intensity of light scattered by gas molecules at a point. From the intensity measurement, gas molecular density can be determined and used to evaluate temperature. An optical system for temperature measurement is presented with a cylindrical control volume of diameter 0.125 mm and 0.5 mm length. An uncertainty analysis demonstrates that temperature can indeed be measured by the system with a high degree of accuracy. An impinging jet type rapid thermal processing test section will be built. Temperature measurements in the reactor test section will be performed using the Rayleigh scattering system. Velocity measurements will be accomplished by Laser-Doppler Velocimeter. Because transient temperature measurements are possible, conditions which lead to thermal instabilities can be identified.
