Signature of Gyrophase Drift: Analysis of Charging Dynamics Relevant to Magnetized-Orbit Dusty-Plasma Confinement and Space-Dust Trajectories

Each dust grain is a heavy charged particle. An electrostatic potential well, arising naturally in the plasma or applied externally, can confine or expel dust grains and the properties of this dusty plasma equilibrium and its dynamics can be studied. The dusty plasma is considered magnetized if the charge-to-mass ratio of the dust grain is sufficiently large that a significant fraction of the grains gyrate with gyro-radii much smaller than the dusty plasma's dimensions perpendicular to the magnetic field and if the dust gyromotion is not prevented by particle collisions. The guiding center drift of a magnetized-orbit dust grain in inhomogeneous plasma depends sensitively on the charging-rate details when the grain gyro-synchronously deviates from being fully charged at its in-situ equilibrium-charge state. Gyro-phase-resonant excursions into a region with inhomogeneity or anisotropy can cause periodic charge-state changes. When such charge-state changes are not instantaneous, a modification, known as gyro-phase drift, to the usual ExB drift, alters the grain's diamagnetic drift vector in ways that may be significant in modeling planetary and lab dusty plasma. We explain, model, and apply the phenomenon in general to space and lab and, specifically, to the Auburn Magnetized Dusty Plasma Experiment.