Confinement of dust particles in a double layer

Negatively charged, micron-sized dust grains have been electrostatically confined in the high-potential region of an anode double layer formed in a single-ended Q-machine plasma. The levitated dust grains are large enough to be visually observed in the scattered light from the plasma source. The various forces on a dust grain in a plasma, i.e., gravitational, electric, ion drag, and neutral drag are estimated based on the measured plasma and dust parameters. The possibility of observing a Coulomb lattice in such a setup is discussed.