Layer structures and the vertical dust lattice instability in a confined plasma crystal

Summary form only given. The formation of plasma crystals confined in an external one-dimensional parabolic potential well was simulated under typical experimental conditions using a computer code called BOX/spl I.bar/TREE. As expected, simulated dust particles formed clear thin layers and the number and positions of the layers changed with the external potential parameter. When the number of layers is constant, the structure of the particles in each layer changes from a square lattice symmetry to a triangular lattice symmetry in agreement with previous theoretical and experimental research. The transition point from a single layer to two layers was examined with dispersion relations of the vertical dust lattice wave around the transition point obtained and analyzed. The transition was shown to be caused by the vertical dust lattice instability, in agreement with previous predictions. Growth rates of the dust lattice instability were calculated employing the simulation data for several external potential parameters and shown to agree with theoretical results.