Dendritic sidebranching initiation by a localized heat pulse

Publisher Website
Google Scholar
Abstract
The response of a growing crystalline dendrite to a brief localized heat pulse applied near its tip was investigated in a directional solidification experiment on succinonitrile containing 1% acetone. The induced deformation was initially unobservably small, but grew rapidly into a sidebranchlike feature with time. This observation supports the proposed selective amplification of noise mechanism for sidebranching. A prelimimary fit to our data of the Gaussian wave-packet description of Pieters and Langer and of Barber, Barbieri, and Langer indicates exponential growth of the perturbation with the 1/4 power of distance.