The grain in the plasma gets charged until the net plasma flux to the grain surface vanishes. In the absence of any analytical formula, this ambipolar condition is utilized to compute the grain charge indirectly. The present work proposes an approximate analytical expression for the grain charge that is exact in the asymptotic limit and in which the relative error between analytical and numerically computed solutions is less than 3%. Using this formula, we show that, much like the plasma sheath, the Bohm criterion is satisfied near the dust surface.
|Number of pages||5|
|Journal||Physical Review E - Statistical, Nonlinear, and Soft Matter Physics|
|Publication status||Published - 6 Jan 2011|