A model for the condensation of a dusty plasma
Abstract
A model for the condensation of a dusty plasma is constructed by considering the spherical shielding layers surrounding a dust grain test particle. The collisionless region less than a collision mean free path from the test particle is shown to separate into three concentric layers, each having distinct physics. The method of matched asymptotic expansions is invoked at the interfaces between these layers and provides equations which determine the radii of the interfaces. Despite being much smaller than the Wigner-Seitz radius, the dust Debye length is found to be physically significant because it gives the scale length of a precipitous cut-off of the shielded electrostatic potential at the interface between the second and third layers. Condensation is predicted to occur when the ratio of this cut-off radius to the Wigner-Seitz radius exceeds unity and this prediction is shown to be in good agreement with experiments.
Cite
@article{arxiv.physics/0403119,
title = {A model for the condensation of a dusty plasma},
author = {P. M. Bellan},
journal= {arXiv preprint arXiv:physics/0403119},
year = {2009}
}
Comments
29 pages, 4 figures, 1 table, to appear in Physics of Plasmas. Manuscript revised on May 1, 2004 to take into account accuracy of Mie scattering dust grain diameter measurement method used in Hayashi/Tachibana experiment. Model now compared to Hayashi/Tachibana experiment using measured rather than fitted dust grain diameter and using higher estimate for Te/Ti (two new references added; revisions made to two paragraphs in Sec. VII, to bottom plot of Fig. 3, and to right-most column of Table 1)