  We study the production and dynamics of heavy quarks in the parton cascade
model for relativistic heavy ion collisions. The model is motivated by the QCD
parton picture and describes the dynamics of an ultra-relativistic heavy-ion
collision in terms of cascading partons which undergo scattering and
multiplication while propagating. We focus on the dynamics of charm quark
production and evolution in p+p and Au+Au collisions for several different
interaction scenarios, i.e. collisions only between primary partons without
radiation of gluons, multiple collisions without radiation of gluons and
multiple collisions with radiation of gluons, allowing us to isolate the
contributions of parton rescattering and radiation to charm production. We also
discuss results of an eikonal approximation of the collision which provides a
valuable comparison with mini-jet calculations and clearly brings out the
importance of multiple collisions.
