First results of Soret Coefficient Measurement Experiment

Abstract

The scope of the Soret Coefficient Measurement Experiment (SCM) is to measure the Soret coefficient in 20 binary organic mixtures and aqueous solutions. Because of the limited mass and power budget, this can be considered as a difficult technical challenge. It has been performed in the Solution Growth Facility in non fully nominal conditions and this has an impact on the accuracy of the measurements obtained as discussed in this presentation. However, the high values obtained for the species segregation in microgravity give very valuable results. They allow for a better understanding of ground based measurements and a definition, using the SCM results as standards, of the best technique to be used. The values of the Soret coefficients will be used in the investigation of the role of the Soret effect in interfacial instabilities (Marangoni-Bénard instabilities in binary mixtures), on morphological instabilities of a planar solidification front and striations and on the buoyancy induced instabilities (Rayleigh-Bénard instabilities).