In situ and tomographic observations of defect free channel formation in ion irradiated stainless steels

► Irradiation-produced defects present strong barriers to dislocation motion. ► Dislocation motion creates defect free channels. ► Channels widen through cross-slip mechanisms and source widening. ► Channels consist of dense tangles and elongated dislocations lining channel walls. ► In situ microscopy and electron tomography allow full characterization of system.