Ionizing radiation is one of the most unique and tunable driving forces for microstructural change. Its application leads to drastic material property changes via the creation of a plethora of defects, whether beneficial or deleterious, over time scales from picoseconds to decades. Thus, ionizing radiation sets off a class of unique phenomena in materials, related to the relatively slow movement and clustering of larger-scale defects compared to the timescale of their creation. These defects are responsible for material property changes, and often manifest themselves as sudden changes in material properties after a long, seemingly dormant nucleation period. A more fundamental understanding of how they form and induce property changes is therefore sought.

Despite over a century of study, our fundamental understanding of precisely how ionizing radiation changes material properties is still incomplete, to the point that we cannot yet predict the performance of a new, known material under a known fluence of radiation. The very nature of such slowly-driven, interaction-dominated phenomena renders radiation-induced microstructural evolution difficult to study, as dose-rate effects, local material inhomogeneities, temperature, and external driving forces such as strain all change both the initial creation and the interactions of radiation-induced microstructural defects. Irradiation therefore exhibits fundamental similarities to longstanding issues such as creep, stress corrosion cracking, and strain-rate dependent deformation, whose mechanistic origins are only recently becoming clear through a concerted effort of theory, simulation, and experiments. Empiricism still pervades all of these fields, which is being replaced with multiscale understanding of how and why these phenomena occur, and their severity as functions of the intrinsic material and external driving forces. This symposium will explore all fundamental aspects of material property changes under ionizing irradiation, especially those which have been difficult to study in the past.

Invited presentations from leaders in their fields will tie together the most recent innovations in the theory, simulation, and experimental measurement of irradiation-induced microstructural evolution. At variance with the previous six symposia of the same series (2006 – 2016), the current symposium scope goes beyond nuclear materials, to invite a broader community to share a more varied and complete picture of how materials evolve out of equilibrium under the driving force of ionizing radiation.

Topics from the fields of ion beam techniques, lithography, ion implantation, electron/ion microscopy, nuclear fuels and structural materials, semiconductor engineering, and radiation-hard electronics will specifically be sought to provide this complete and diverse picture. Sessions will be organized around physical mechanisms and methodologies, not classes of materials, to ensure that attendees can draw parallels between material systems in every session.

diffusion electron irradiation embrittlement ion-beam processing kinetics microstructure neutron irradiation radiation effects simulation thermal conductivity