506 Chapter 17. Dusty plasmas
potential fields. Assume thatZd=10^4 and that the dust grains are made of a material
which has a mass density of 1 gm/cc.- Suppose a negatively charged dust grain has a chargeZdand a radiusrd.Show that the
potential on the surface of the dust grain is much less thanZd/ 4 πε 0 rdifrd>>λD
whereλDis the nominal shielding length for the shielding cloud around the dust grain.
What implication does this have for dust charging theory and why do interesting dusty
plasmas typically haverd<<λD?