Properties of dust-plasma structures formed in a glow discharge above the lower wall of the discharge chamber

• Published in: Plasma physics reports 2012-07, Vol.38 (7), p.540-544
• Main Authors: Dzlieva, E. S., Ermolenko, M. A., Karasev, V. Yu
• Format: Article
• Language: English
• Subjects: Atomic; Dusty Plasma; Molecular; Optical and Plasma Physics; Physics; Physics and Astronomy
• ISSN: 1063-780X; 1562-6938
• DOI: 10.1134/S1063780X12060013

The properties are studied of dusty plasma structures formed in a glow discharge in a dust trap above the lower wall of the side branch of the discharge tube, near the turn of the discharge channel. The dust structure is three-dimensional with a characteristic size of up to 3 cm and contains about 30000 dust grains. Depending on the experimental conditions, dust-acoustic, dissipative, and charge-gradient instabilities can develop in such a structure. When using highly polydisperse dust grains of arbitrary shape, the effect of selection of dust grains by the plasma with respect to their mean size and shape was discovered. This effect was studied quantitatively in two gases by using the method of gathering and extraction of the dust grains levitating in the trap. The morphology of the dust structures was determined from the pair correlation functions of the horizontal cross sections containing long-range order peaks and elements of a hexagonal lattice. Stratification of a uniform structure accompanied by convective rotation caused by the grain charge gradient was observed. Applications of the dusty plasma created in this type of device are discussed.