Filamentary and Resonant Drag Instabilities in Laboratory and Astrophysical Dusty Plasmas*

Previous work on the filamentary instability seen in laboratory dusty plasmas has demonstrated that its onset is associated with a resonance between dust and ion acoustic modes and is mediated by drag between these species.[1] Recent work on resonant drag instabilities (RDIs), which are driven by resonance between fluid waves and dust streaming through the fluid, suggests that RDIs have significant implications for planet formation.[2] Motivated by similarity between these physical pictures, we have developed a general framework for the study of both of these instabilities and the conditions for their appearance, with the objective of studying their linear and nonlinear properties more exhaustively in dusty as well as other low-temperature laboratory experiments (including microgravity conditions). We demonstrate that the filamentary instability is analogous to a zero-drift velocity-RDI. Unlike normal RDIs, we find that the addition of a nonzero streaming velocity strongly affects and eventually suppresses the filamentary instability. Further generalizations, including the consideration of plasma and dust charging effects in astrophysical systems, are considered.

[1]X. Wang, et. al. Physics of Plasmas 8, 5018 (2001).

[2]J. Squire and P. F. Hopkins, MNRAS 477, 5011 (2018).