Generation and Characterization of Chaotic Convection in Collisional Plasma

Turbulence in the plasma sheath around reentry vehicles is known to contribute to radio-communications blackout, but a practical laboratory model of that extreme environment remains elusive. Herein, we present a table-top plasma system with sustained, chaotic convection for that purpose. Strong sound waves exert acoustic radiation pressure on gradients within the plasma and are shown to drive sufficient convection to cause abrupt and chaotic variation in the plasma properties. The volume-averaged plasma conductivity and collision time are determined in real time by phase-sensitive detection of a microwave probe signal. The experiment provides unique opportunities to study transmission into plasma conditions that can inform detailed models of high-temperature turbulent flows.