Dust plasma behavior observed in three dimensions in microgravity during parabolic flights
Dust plasma behavior observed in three dimensions in microgravity during parabolic flights lead image
Due to their easily observable behavior and similarities with fluids, studying dusty plasmas has become increasingly important for understanding sonic boom dynamics. To date, many dust studies have been conducted using two-dimensional systems to study phenomena such as turbulence. New experiments in microgravity look to shed light on dust behavior in the vicinity of an obstacle in a large, undisturbed system.
Schütt et al. examined dust flows around obstacles in three-dimensionally extended dust clouds during parabolic flights. Using a tungsten wire strung in the middle plane between two parallel radio-frequency electrodes, they were able to shift dust clouds periodically by superimposing a low-frequency modulation on the electrodes.
This marks one of the first times a three-dimensionally extended dust cloud was studied while controlling dust flow and observing it with high-resolution diagnostics.
“There has been a history of different experiments on bow shocks and turbulence in various geometries,” said author Stefan Schütt. “We hope that our work paves the way for a new type of experiment for investigations of such dust flows that allows a three-dimensional analysis in extended dust clouds.”
As dust flows between the electrodes approached the sound barrier, bow shocks formed upstream of the wire and propagated away at constant speeds, maintaining a constant width. The group found a complex interplay between dust density, shock formation, particle charge, and dust-density waves.
The researchers concluded that shocks were excited by dust reaching critical densities, rather than through the flow of ions.
The group hopes their findings provide background into the early phase of emerging bow shocks and next look to examine longer dust flow times and downstream effects.
Source: “Bow shock formation in a dusty plasma flowing around an obstacle under microgravity,” by S. Schütt, C. A. Knapek, D. Maier, D. P. Mohr, and A. Melzer, Physics of Plasmas (2025). The article can be accessed at https://doi.org/10.1063/5.0252819 .
