Dusty plasma (Yukawa) rings

One-dimensional and quasi-one-dimensional strongly-coupled dusty plasma rings have been created experimentally. Longitudinal (acoustic) and transverse (optical) dispersion relations for the 1-ring were measured and found to be in very good agreement with the theory for an unbounded straight chain of particles interacting through a Yukawa (i.e., screened Coulomb or Debye-H\"uckel) potential. These rings provide a new system in which to study one-dimensional and quasi-one-dimensional physics.