Resonance instability: the link between drag and electrostatic interactions in dusty plasmas

The physics of dusty plasmas is of great interest in both astrophysical and laboratory contexts. Its applications range from investigating the cosmic-scale dust bunnies that may evolve into planets to soft condensed matter physics and semiconductor manufacturing. Recent research termed one class of phenomena found in fluid-dust systems as resonant drag instabilities (RDIs), which can occur when dust streams through fluid supporting at least one oscillatory mode. The resonance phenomenon produced, however, is not specific to RDIs.

Israeli et al. noticed a similarity between filamentary ionization instability and RDIs—the former being a laboratory phenomenon, and the latter observed in astrophysics. In addition to drag interactions, they were especially interested in the electrostatic effects of charged dust particles in plasma.

“Both instabilities involve drag between dust and a background fluid, both drive large fluctuations in dust density, and both are driven by a resonance between the dust and fluid parts of the system,” said author Ben Israeli. “This led to us asking whether they might somehow be related to each other.”

After comparing the resonance behavior and growth rates of a range of instabilities with RDIs, the team found that these instabilities, driving dust clumping in different regimes, can be attributed to a particular type of dust-plasma resonance—a framework they coined as resonance instability.

“Our future goals include extending our understanding of the endpoint of the evolution of acoustic resonant drag instability, namely the turbulent flow and filamentary dust structures it produces,” said Israeli. “Similar study of the nonlinear evolution of other resonant instabilities, either individually or in combination, is also an area of active work with much to be done.”

Source: “Resonant instabilities mediated by drag and electrostatic interactions in laboratory and astrophysical dusty plasmas,” by Ben Y. Israeli, Amitava Bhattacharjee, and Hong Qin, Physics of Plasmas (2023). The article can be accessed at https://doi.org/10.1063/5.0151645 .