The Energy Dissipation to Defect Evolution (EDDE) EFRC aims to develop a fundamental understanding of how the energy of radiation is dissipated, and ultimately to control defect dynamics and microstructural evolution in structural alloys. Specifically, we seek to understand and quantify the mechanisms of energy dissipation through electronic, vibrational and magnetic excitation, their impact on atomic processes that control defect production and recombination under irradiation, and how their dissipation mechanisms are influenced by alloy complexity.

Two thrusts are designed to test our hypothesis that alloy complexity can be tailored to reduce defect production and enhance recombination. We will address the challenges on Energy Dissipation in Thrust 1 and Defect Evolution in Thrust 2.” In this Center, we take advantage of recent successes in synthesis of nontraditional multi-element alloys with compositions at or near equiatomic ratios, including high entropy alloys, to go beyond traditional alloy development. Our emphasis will be on single-phase solid-solution alloys with two to five principal elements. We aim to develop strategies to minimize defect production as well as encourage defect recombination. The Center will also take advantage of recent theoretical and computational developments, many of them by members of our Center, to explore for the first time a comprehensive electronic and atomic description of an irradiated material very far from equilibrium. State-of-the-art synthesis, controlled irradiations, in situ ion beam analysis, and post-irradiation microstructure characterization techniques will all be utilized, including channeling image scans, advanced analytical transmission electron microscopy, atom probe tomography, and X-ray and neutron scattering methods. Experimental results, especially on model alloys, will be quantitatively compared to predictions from specialized density functional theory, classical molecular dynamics, and kinetic Monte Carlo techniques.  The combination of experiments and these multi-scale computational approaches will offer us the possibility to probe and understand the critical knowledge for controlling and engineering material properties and performance at the ultimate scale – that of atoms and electrons.

The EDDE Center engages a diverse mix of principal investigators and senior/key personnel who have complementary experience and skills. Each thrust will incorporate both theory and experiment. Most participants will contribute to both thrusts, thus maximizing synergies and coordination. The strong university involvement will enhance educational outreach. The success of the EDDE Center will yield new design principles for radiation-tolerant structural alloys for applications in nuclear energy and new defect engineering paradigms for much broader science and technologies.

— Yanwen Zhang, Director