Time Evolution of Three-Dimensional Structural State in Microgravity Dusty Plasma

Dusty plasmas are collections of charged macroscopic particles (referred to as “dust”) in low temperature, weakly ionized plasma. As the dust grains collect charge from the free-moving electrons in the plasma cloud, they become negatively charged and are observed to organize in complex structural states. Here we analyze data from the Plasmakristall-4 microgravity dusty plasma experiment on board the International Space Station. Previous studies of dust clouds in the PK-4 experiment have suggested that anisotropic dust-dust interactions lead to the formation of exotic structural states reminiscent of liquid crystal states [1], such as smectic and nematic structures. We extend those previous studies for datasets that used improved temporal resolution through a reduced FOV and corresponding increased camera frame rate for better imaging and data. In these experiments, the clouds are trapped in the camera field of view using a polarity-switched axial electric field. The time evolution of the dusty plasma structural state is studied using pair correlation functions calculated for particles within the central plane of the dust cloud and within successive planes of the cloud (the 3D cloud).

[1] https://doi.org/10.48550/arXiv.2505.14576