An investigation was made of the defects which were created in optical-grade fused silica due to 200MeV Ag-ion bombardment. Paramagnetically positively charged O vacancies or neutral dangling Si bonds (E’ centers), non-bridging O hole centers and non-paramagnetic defects like B2 bands were observed. The fluence dependent optical and paramagnetic behaviors of these defects were studied by using UV–visible absorption spectroscopy, photoluminescence spectroscopy, infra-red absorption and electron paramagnetic resonance. It was observed that the generation of E’ centers, non-bridging O hole centers and B2 bands saturated beyond a fluence of 1012/cm2. Infra-red spectra which showed saturation of transmission at this fluence also support this observation. At this fluence samples became fully covered with latent tracks which contained these defects.

Dense Electronic Excitation Induced Defects in Fused Silica. T.Mohanty, N.C.Mishra, S.V.Bhat, P.K.Basu, D.Kanjilal: Journal of Physics D, 2003, 36[24], 3151-5