On the Measurements of Small Amplitude Side-Branch Spacing at the Dendrite Tip
Abstract
The focus of this ongoing research is to analyze the tip region of dendrites in order to find out if there is evidence of side-branching in the "smooth" tip regime. More recently it has been reported that the dendrites do not grow at a steady-state velocity, and that there are growth velocity oscillations at the tip. Extracting a smooth curve from the dendrite, we measured correlations in the deviation between the actual dendritic interface and the smooth reference as a function of arclength. These results constitute a wavenumber spectrum of perturbations at the dendrite tip. One way to quantify the side-branch structure is to measure the distance between adjacent side-branches, which we call the side-branch spacing, λ. Results show that the inverse of these wavenumbers, which is a spacing, when scaled by the tip radius, yields λ _tip-wavenumber/R = 3.1. This is about the same as the measured side-branch spacing of λ _side-branching/R = 2.9. This constitutes the first experimental evidence that there is side-branch activity at the tip.
- Publication:
-
APS New England Section Fall Meeting Abstracts
- Pub Date:
- November 2001
- Bibcode:
- 2001APS..NEF.AA002D