Force fields and simulation of ultra high temperature ceramics for fusion applications

The development of fusion reactors depends on a combination of the insight from multiple disciplines at a wide range at length and timescales. An important part of any future fusion reactor are materials that are exposed to extreme radiation and temperature conditions as plasma facing components. While a significant amount of research has focused on refractory alloys, another class of promising materials are ultra high temperature ceramics and TiB2 is one of the most promising candidates. A very limited information is available on the radiation effects and defects properties in TiB2, thus we consider an atomistic simulation approach to investigate those. To model microstructure evolution and surface erosion, we perform a combination of first principles static and molecular dynamics (MD) simulations and derive machine learned (ML) force fields to achieve DFT like accuracy in classical MD simulations. We will present our ML force fields for TiB2 and Deuterium and compare the accuracy and performance of classical MD simulations using these potentials to first principles DFT simulations.