Atomistic simulations of threshold displacement energies in SiO2

Silica is one of the candidate materials for final focusing mirrors in inertial fusion reactors. This material will be exposed to high neutron irradiation fluxes during operation. Radiation damage results in point defects that can lead to obscuration of this material; that is, degradation of the optical properties of silica. In this paper, we present molecular dynamic simulations of defect production in silica glass. Results on the threshold displacement energies due to oxygen primary knock-on atoms (PKA) are reported concluding that a range of energies (20–40 eV) exists in which the defects have a probability to be created. In addition, we determine a range of distances for a PKA to become a stable defect from its original position. Our present analysis is focused on the formation of oxygen deficient centers (ODC).