(208g) Probes of Supercritical CΟ2 by Deflection of Multiple Beamlets

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.