  This study examines the effect that dipole-dipole charge interactions between
fractal aggregates have on the growth of dust grains. Aggregates in a plasma or
radiative environment will have charge distributed over their extended surface,
which leads to a net dipole moment for the charged grains. A self-consistent
N-body code is used to model the dynamics of interacting charged aggregates.
The aggregates are free to rotate due to collisions and dipole-dipole
electrostatic interactions. These rotations are important in determining the
growth rate and subsequent geometry (fractal dimension) of the grains. In
contrast to previous studies which have only taken charge-dipole interactions
into account, like-charged grains are found to coagulate more efficiently than
neutral grains due to preferential incorporation of small aggregates into
mid-sized aggregate structures. The charged aggregates tend to be more compact
than neutral aggregates, characterized by slightly higher fractal dimensions.

Plasma Physics