Generalized framework for interatomic potential design: Application to Fe-He system

Radiation damage phenomena plays an important role in the lifetime of structural materials for future fusion power reactors. Developing predictive multiscale models for material behavior under irradiation conditions in a fusion reactor requires understanding the mechanisms associated with radiation damage phenomena, the He interaction with microstructures, and quantifying the associated uncertainties. Nanoscale simulations and interatomic potentials play an important role in exploring the physics of nanoscale structures. However, while interatomic potentials are designed for a specific purpose, they are often used for studying mechanisms outside of the intended purpose. Hence, a generalized framework for interatomic potential design is designed such that it can allow a researcher to tailor an interatomic potential towards specific properties. This methodology produces an interatomic potential design map, which contains multiple interatomic potentials and is capable of exploring different nanoscale phenomena observed in experiments. This methodology is efficient and provides the means to assess uncertainties in nanostructure properties due to the interatomic potential fitting process. As an initial example with relevance to fusion reactors, an Fe-He interatomic potential design map is developed using this framework to show its profound effect.