Latest Results on Complex Plasmas with the PK-3 Plus Laboratory on board the International Space Station

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Kurzfassung

Complex plasmas are low temperature plasmas that contain microparticles in addition to ions, electrons, and neutral particles. The microparticles acquire high charges, interact with each other and can be considered as model atoms for effects such as crystallization and fluid movement. In contrast to atoms in ordinary systems, their movement can be traced on the most basic level, tht of individual particles. The PK-3 Plus Laboratory was operated on board the International Space Station from 2006 - 2013. Its heart consisted of a capacitively coupled radio-frequency plasma chamber. Microparticles were inserted into the low-temperature plasma, forming large, homogeneous complex plasma clouds. Here, we present the latest results obtained with PK-3 Plus: The onset of turbulence. We study how the kinetic energy spactra of the microparticls change when the complex plasma undergoes an instability and becomes turbulent. We compare the spectra with the double cascade predicted for two-dimensional forced turbulence. Density waves at the interface of a binary complex plasma. We study how density waves are transmitted across the interface between two mediums by considering a binary complex plasma that is composed of microparticles of two sizes. We show that a collision zone and a merger zone develop before and after the interface. Sphere - complex plasma interaction. In the experiment presented here, 1 mm diameter metallic spheres were present in the complex plasma in addition to microparticles. We study the interaction between the complex plasma and the spheres and show that the spheres strongly affect both the local plasma environment and the microparticles. Crystallization. We melt a complex plasma crystal and study how the microparticle cloud re-crystallizes. We examine the three-dimensional propagation of crystallization fronts by scanning through the cloud and measuring the mean square displacement of the microparticles.

Verfügbare Versionen dieses Eintrags

• Latest Results on Complex Plasmas with the PK-3 Plus Laboratory on board the International Space Station. (deposited 10 Okt 2017 18:00) [Gegenwärtig angezeigt]