Abstract: Disclosed herein is an interferometric-based materials analysis system (10) that employs a novel combination of laser beam shaping and pointing techniques, the use of a low cost, rugged, and compact diode laser (22) as a detection laser, and the use of signal processing techniques that compensate for inherent instabilities and short-term drift in the diode laser. A matched filter processing technique is disclosed for processing interferometrically-obtained data points from a target being analyzed. The matched filter technique is shown to be especially useful for detecting and analyzing Lamb modes within thin targets, such as a silicon wafer undergoing a rapid thermal processing cycle. Also disclosed is a method and apparatus for interferometrically monitoring a target to determine, in accordance with predetermined criteria, an occurrence of a period of time that is optimum for obtaining a data point.

Abstract: A tuyere for use in a metallurgical vessel comprising a first pipe adapted to be affixed to the wall of a metallurgical vessel and having a first end extending through the refractory lining of the vessel and a second end extending outwardly therefrom. A gas inlet member is affixed to the second end of the pipe and the second pipe is affixed to the gas inlet member and extends inwardly through the first pipe. The outer diameter of the second pipe is smaller than the inner diameter of the first pipe to provide a gap there between. Means are provided between the first and second pipes to maintain them in spaced-apart relation and the interior of the first pipe is filled with a material such as refractory.