  In this work we develop an ab initio informed rate theory model to track the
spatial and temporal evolution of implanted ions (Cr+) in Fe and Fe-14%Cr
during high dose irradiation. We focus on the influence of the specimen
surface, the depth dependence of ion-induced damage, the damage rate, and the
consequences of ion implantation, all of which influence the depth dependence
of alloy composition evolving with continued irradiation. We investigate
chemical segregation effects in the material by considering the diffusion of
the irradiation-induced defects. Moreover, we explore how temperature, grain
size, grain boundary sink strength, and defect production bias modify the
resulting distribution of alloy composition. Our results show that the
implanted ion profile can be quite different than the predicted SRIM
implantation profile due to radiation enhanced transport and segregation.
