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Ed Thomas: Using magnetic fields and microgravity to explore the physics of dusty plasmas

Professor of Physics and Associate Dean for Research and Graduate Studies
College of Sciences and Mathematics
Auburn University

Over the last three decades plasma scientists have learned how to control a new type of plasma system known as a “complex” or “dusty” plasma.  These are four-component plasma systems that consist of electrons, ions, neutral atoms, and charged, solid, nanometer- to micrometer-sized particles.  The presence of these microparticles allow us to “tune” the plasma to have solid-like, fluid-like, or gas-like properties.  This means that dusty plasmas are not just a fourth state of matter – they can take on the properties of all four states of matter. 

From star-forming regions to planetary rings to fusion experiments, charged microparticles can be found in many naturally occurring and man-made plasma systems.  Therefore, understanding the physics of dusty plasmas can provide new insights into a broad range of astrophysical and technological problems.  This presentation introduces the physical properties of dusty plasmas – focusing on how the small charge-to-mass ratio of the charged microparticles gives rise to many of the characteristics of the system.  In particular, dusty plasmas can be used to study a variety of processes in non-equilibrium or dissipative systems such as self-organization and energy cascade as well as a variety of transport and instability mechanisms.  This presentation will discuss results from our studies of dusty plasmas in high (B ≥ 1 T) magnetic fields using the Magnetized Dusty Plasma Experiment (MDPX) device at Auburn University and in microgravity experiments using the Plasmakristall-4 (PK-4) laboratory on the International Space Station.