The role of the fused silica stoichiometry on the intrinsic defects concentration

Silica is one of the reference materials for optical systems in Fusion Technology both in magnetic (ITER) and in inertial (NIF) confinement concepts. Its properties of interest (such as optical absorption, radioluminescence or mechanical properties) are closely related to the presence of defects which may be intrinsic to the material, generated by irradiation, or associated to impurities. In this work the types of intrinsic defects and their concentration as a function of stoichiometric deviations are studied using classical molecular dynamics. The Feuston–Garofalini potential is assessed in this study by analysing the obtained defects. The structural properties of defects found by computer simulations are characterized and compared with known defects in silica.