208g Probes of Supercritical CΟ2 by Deflection of Multiple Beamlets

Erhard W. Rothe and Irina Robu. Chemical Engineering, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI 48202

We describe the creation of sets of 633-nm beamlets and their bending by supercritical CO2. Small temperature gradients within a cell that contains the fluid resulted large density-gradients that, in turn, are almost proportional to gradients of optical refractive index. The paths of such beamlets can be described quantitatively. Beamlets were made with a He-Ne laser-beam that impinged on an array of apertures. The transmitted light forms Fraunhofer diffraction patterns whose shapes depend upon the arrangement of the apertures. The beamlets traversed a 7.62 cm-long cell and were deflected downward to a degree that depended upon the spatial distribution of CO2 density. The deflection is as much as 0.25m at a distance of 2m.