  Atomistic simulations are used to explore the effect of interfacial structure
on residual radiation damage. Specifically, an ordered grain boundary is
compared to a disordered amorphous intergranular film, to investigate how
interface thickness and free volume impacts point defect recombination. The
collision cascades induced by neutron bombardment are simulated and residual
point defect populations are analyzed as a function of boundary type and
primary knock on atom energy. While ordered grain boundaries easily absorb
interstitials, these interfaces are inefficient vacancy sinks. Alternatively,
amorphous intergranular films act as ultra-efficient, unbiased defect sinks,
providing a path for the creation of radiation-tolerant materials.
