  In order to characterize the early growth of fine-grained dust rims (FGRs)
that commonly surround chondrules, we simulate the growth of FGRs through
direct accretion of monomers of various sizes onto the chondrule surfaces. Dust
becomes charged to varying degrees in the radiative plasma environment of the
solar nebula (SN), and the resulting electrostatic force alters the
trajectories of colliding dust grains, influencing the structure of the dust
rim as well as the time scale of rim formation. We compare the growth of FGRs
in protoplanetary disks (PPD) with different turbulence strengths and plasma
conditions to previous models which assumed neutral dust grains. We use a
combination of a Monte Carlo method and an N-body code to simulate the
collision of dust monomers with chondrules: a Monte Carlo algorithm is used to
randomly select dust particles that will collide with the chondrule as well as
determine the elapsed time interval between collisions; at close approach, the
detailed collision process is modeled using an N-body algorithm, Aggregate
Builder (AB), to determine the collision outcome, as well as any restructuring
of the chondrule rim. The collisions are driven by Brownian motion and coupling
to turbulent gas motion in the protoplanetary disk. The charge distribution of
the dust rim is modeled, used to calculate the trajectories of dust grains, and
then analyze the resulting morphology of the dust rim. In a weakly turbulent
region, the decreased relative velocity between charged particles causes small
grains to be repelled from the chondrule, causing dust rims to grow more slowly
and be composed of larger monomers, which results in a more porous structure.
In a highly turbulent region, the presence of charge mainly affects the
porosity of the rim by causing dust particles to deviate from the extremities
of the rim and reducing the amount of restructuring.
