Dynamics of a Dust Crystal with Two Different Size Dust Species.pdfVIP

Dynamics of a Dust Crystal with Two Different Size Dust Species L.S. Matthews, K. Qiao, T.W. Hyde CASPER (Center for Astrophysics, Space Physics, and Engineering Research), Baylor University, Waco, Texas 76798-7310, USA (Truell_Hyde@baylor.edu) Abstract A self-consistent three-dimensional model for a complex (dusty) plasma is used to study the effects of multiple-sized dust grains in a dust crystal. In addition to the interparticle forces, which interact through a Yukawa potential, the model includes the effects of gravity, the variation of the sheath potential above the powered electrode, and a radial confining potential. Simulations studied various ratios of a mix of 6.5- and 8.9-micron monodisperse particles and compared their correlation functions, electric potential energy of the crystal formations, and the dispersion relations for in-plane and out-of-plane dust lattice wave (DLW) modes for two different sheath thicknesses. In the 7 mm sheath, the particles formed two layers in the vertical direction by size, and acted as a two-layer crystal with weak correlation between the layers. In the 3 mm sheath, the particles formed an essentially monolayer crystal; however the crystal dynamics showed some characteristics of a bilayer crystal. 1. Background 2003). The dispersion relation of a wave mode is defined as the relationship between the angular The two-dimensional (2D) plasma crystal frequency (or frequency) and the wave number produced in a typical laboratory complex plasma (or wavelength). It provides the fundamental environment is formed when negatively charged properties of a given wa