The Very-Small Angle Neutron Scattering from Neutron-Irradiated Amorphous Silica

The very-small-angle neutron scattering has been measured for amorphous silica which had been reactor-irradiated with a thermal neutron fluence of 3×10 19 /cm 2 at 48°±2°C. Structural inhomogeneities were revealed with a radius of gyration of 3×10 5 A. The observation is consistent with that of the very-small-angle X-ray scattering (Suzuki et al. Jpn. J. Appl. Phys. 19 (1980) L205) and with optical microscopy.