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Limitation of electrostatic charging of dust particles in a plasma
Author(s) -
Goertz C. K.,
Ip W.H.
Publication year - 1984
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl011i004p00349
Subject(s) - dusty plasma , plasma , physics , debye length , atomic physics , radius , saturn , observable , plasma parameters , astrophysics , planet , quantum mechanics , computer security , computer science
We show that in a dusty plasma consisting of a plasma (density n and temperature T) and dust grains (density N and radius a) the charge on a grain is not given by its free‐space value Q o = Va, where V is its surface potential. Instead the charge is reduced by a factor 1 + x, with x = 4πNaλ D ², where λ D is the plasma Debye length. Except in the optically thin E and G rings this factor is large. Usually electromagnetic forces on dust particles in Saturn's ring system are too small to produce observable effects. The current carried by dust particles moving relative to the plasma with a speed w is to a good approximation given by j = NQw. Thus magnetic perturbations by the F ring should be much smaller than previously estimated.