Characterization of dynamics of quasi-stable filamentary structures in the Magnetized Dusty Plasma eXperiment (MDPX)

At sufficiently high magnetic fields (B > 0.5 T), experiments in the Magnetized Dusty Plasma eXperiment (MDPX) at Auburn University, a capacitively-coupled, low-temperature plasma device, have shown the presence of filamentary structures. These appear as bright columns, elongated along the applied magnetic field, when viewed in the plane perpendicular to the magnetic field. Controlled changes in the parameters, including pressure, rf power, and gas type result in unique morphologies. Most commonly, the filaments appear as circular or multiple-arm spiral-like shapes. However, many times the filaments have complex structures, and we use an azimuthal mode decomposition to more precisely characterize these morphologies. Consequently, we can better understand which filament structures and plasma parameters are conducive to stable lifetimes of filaments and which lead to more complex dynamics including the particular case of a ring-shaped filament that exhibits a quasi-periodic lifetime.