INTERFEROMETRIC MEASUREMENT OF THE TEMPERATURE FIELD IN THE VICINITY OF AN EVOLVING DENDRITE CRYSTAL

by Dharmatilleke, Medha

The process of crystallization from a succinonitrile melt is investigated using interferometry. Succinonitrile is the most suitable chemical for this process because of its convenient melting point. It is a transparent and colorless chemical. Circulating heated water bath controls the temperature of the sample. The cell and the container have eight parallel glass windows, which are properly aligned to each other to provide the path for each of four interferometer beams. In the current experiment only one beam was used. The cell is then placed in one arm of the Mach-Zehnder interferometer to investigate the interference pattern. The interference pattern is video recorded before and while the crystal is grown. The fringe pattern as a function of time is captured with a frame grabber and then analysed using a computer program to extract information from the variation of the index of refraction in the melt.