Regensburg 2004 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 25: Growth and Roughness

DY 25.2: Vortrag

Dienstag, 9. März 2004, 15:15–15:30, H3

Three Dimensional Reconstruction of Experimentally Grown Xenon Dendrites and Doublons. — •Herman M. Singer and Jörg H. Bilgram — Laboratorium für Festkörperphysik, ETH Zürich, 8093 Zürich (Schweiz)

We investigate in our in situ experiments three dimensional xenon crystals during free growth into pure supercooled melt. Supercooling is the only control parameter of the system and determines the morphology of the crystal. We present a method of reconstructing quantitatively the three dimensional shape of an experimentally grown xenon dendrite based on a hybrid approach of sophisticated image processing and measured parameters of dendrites. This new method can readily be applied to other experimental fields where transparent substances are to be investigated. We can prove that the development of the fourfold symmetry of the fins is not merely a result of a modulating perturbation but an inherent structure formation process. We have found a power law dependence for volume and surface on distance from the tip and time. We present the 3D reconstruction of experimental doublons and their temporal evolution as well as their relaxation.