X-ray diffraction from neutron-irradiated vitreous silica

Both large-angle and small-angle diffraction studies have been made on pile irradiated silica glass. The radial distribution curves obtained from the large-angle scattering were in essential agreement with the earlier work of Simon. The small-angle scattering from samples irradiated with a relatively low fast neutron dose showed a noticeable rise in the scattering at the smallest angles. Two possible causes of this scattering are suggested. In addition, all irradiated samples showed a general increase in the scattering over the entire small-angle region. This scattering which showed little angular dependence was attributed to increased density fluctuations within the sample after irradiation. The irradiation induced scattering was almost completely removed by annealing the glass at 1300°C.