New approach to measurement of the three-dimensional crystallization front propagation velocity in strongly coupled complex plasma

Abstract

The PK-3 Plus laboratory onboard the International Space Station is used to form complex plasma with a liquidlike particle subsystem in metastable state and to observe the propagation of crystallization fronts corresponding to the surfaces of crystal domains. We propose the "axis" algorithm of solidlike particles identification, which makes it possible to isolate different domains and their surfaces as well. Determination of the three-dimensional front velocity is based on its definition implying that there exists a small area of the domain surface propagating along some line perpendicularly to it. The velocity measured in this way is an important characteristic of the plasma crystallization kinetics. It proves to be almost independent of time and the direction of front propagation and amounts to ca. 60-80 µm s −1 .

Spontaneous dust pulse formation in the afterglow of complex plasmas under microgravity conditions

“…The experiments presented here were performed in the PK-3 Plus Laboratory [20,[43][44][45] which was a Russian-German laboratory hosted on board the ISS during 2006 -2013. This microgravity laboratory made it possible to explore the interdisciplinary features of complex plasmas with several dedicated experiments on diverse topics such as the heartbeat instability and its effect on the microparticle dynamics [46,47], phase separation [48], lane formation [49], crystallization [48,[50][51][52], electrorheological plasmas [53], and interface effects [54,55].…”