Berlin 2015 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 45: P10: Colloids and Complex Liquids

CPP 45.3: Poster

Wednesday, March 18, 2015, 10:00–13:00, Poster A

Phase Unwrapping of two-dimensional interferograms - Preparations for the DCMIX-3 experiment on board the ISS — •Thomas Triller and Werner Köhler — Physikalisches Institut, Universität Bayreuth, 95440 Bayreuth, Germany

The DCMIX project is an international effort to investigate diffusive transport in ternary fluid systems in the presence of a temperature gradient. In certain systems these processes are prone to gravitational instability. Therefore, experiments have been designed in a microgravity environment on board the ISS with SODI (Selectable Optical Diagnostics Instrument). SODI is a variation of a Mach-Zehnder interferometer and thus generates two-dimensional interferograms of a thermodiffusion cell. To analyse these interferograms and extract transport coefficients (e.g. the Soret coefficients of the diffusing components), the image information has to be processed with the Phase Unwrapping method. Such image processing is necessary, because the phase information ψ(t) in the images is wrapped into the range (−π,π]: ψ(t) = ϕ(t) + 2 π k(t) with k(t) an integer function. The full phase ϕ(t) has to be reconstructed with proper algorithms. As preparations for the DCMIX-3 experiment (the system Water/Ethanol/Triethylene-glycol), several algorithms for Phase Unwrapping have been implemented and compared.