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Notes:
A paper in Physical Review in February 2000, discusses what happens when the dust is levitated in the presence of a strong magnet.
As the experimental setup illustrates, a strong magnet forms the base of the experiment, and a RF power source is applied to the magnet to generate a plasma around it. Dust is sprinkled on the magnet, and as the plasma charges up the dust, a ring shaped electrode above the magnet is used to create a vertical electric field that levitates the dust in a thin layer above the magnet. A sheet of laser light, formed by shining a laser through a cylindrical lens, illuminates the dust and a CCD camera above the magnet is used to record positions of the dust. The dust forms a Coulomb crystal which experiences a magnetic force that causes the dust to circulate as if it were a rigid disk. This result is so reminiscent of Saturn’s rings, that perhaps it inspired the following experiment