DOUBLE-BEAM X-RAY RADIOGRAPHY SYSTEM FOR 3-DIMENSIONAL FLOW VISUALIZATION OF MOLTEN SILICON CONVECTION

A ''double-beam X-ray radiography system'' is developed for three-dimensional visualization of the flow of molten silicon convection during Czochralski crystal growth. The system contains two sets of X-ray sources and X-ray cameras set at right angles to each other. Tracers are tracked in three dimensions by stereoscopic photograph theory. The new system is described in detail and three-dimensionally visualized particle paths of molten silicon convection are presented. This visualization technique shows that the azimuthal flow direction of molten silicon strongly depends on the crucible and crystal rotations rates, and they can be categorized using the relationship between the crystal and crucible Reynolds numbers.