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Structure and trapping of three-dimensional dust clouds in a capacitively coupled rf-discharge.

Authors :
Arp, O.
Block, D.
Piel, A.
Source :
AIP Conference Proceedings. 2005, Vol. 799 Issue 1, p20-28. 9p. 4 Diagrams, 9 Graphs.
Publication Year :
2005

Abstract

In this survey the recently found “Coulomb balls” are discussed, which show an unusual kind of crystalline order. These three-dimensional dust clouds consisting of hundreds or thousands of micrometer-sized dust particles have a spherical shape and exist in a wide range of plasma conditions. Coulomb balls are optically highly transparent and have macroscopic dimensions of several millimeters in diameter. The clouds allow for the observation of each single particle and thus the complete reconstruction of the crystal structure by means of video microscopy techniques. The particles are arranged in distinct nested shells in which they form patterns with mostly five and six neighbors. The confinement of Coulomb balls by dielectric walls involves electric forces, surface charges, ion drag forces, and thermophoretic levitation. The thermophoretic force field is measured with tracer particles and particle image velocimetry (PIV). The electric forces are derived from simulations with the two-dimensional SIGLO-2D code. It is shown the the sum of all confineing forces results in a stable potential well that describes levitation and spherical confinement of the Coulomb ball. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
0094243X
Volume :
799
Issue :
1
Database :
Academic Search Index
Journal :
AIP Conference Proceedings
Publication Type :
Conference
Accession number :
18738203
Full Text :
https://doi.org/10.1063/1.2134569