Evaluation of tungsten interatomic potentials for radiation damage simulations

Abstract

The structure and properties of materials under neutron irradiation are an important basis in future fusion reactors. In the absence of fusion neutron sources for irradiation experiments, it is increasingly important and urgent to carry out neutron irradiation simulations on fusion reactor materials and then establish complete databases of defect properties and collisional cascades, where the first and foremost step is to select suitable interatomic potentials for atomistic-level simulations. In this work, six typic interatomic potentials for tungsten (W) are evaluated and reviewed systematically for radiation damage simulations. The relative lattice stability and elastic constants of bulk W are considered first with those potentials; then, the properties of point defects and defect clusters at interstitial sites and vacancies are obtained by molecular statics/dynamics simulations. The formation energies of interstitial/vacancy clusters, 1/2 〈111〉 and 〈100〉 dislocation loops in W and the threshold displacement energies along different directions are also determined. In addition, the extended defects are further investigated, such as free surfaces and the energy profiles of 1/2 〈111〉 {110} and 1/2 〈111〉 {112} stacking faults. The current results provide a reference for selecting W potentials to simulate the radiation damage.