Characteristics of gamma-ray-induced absorption bands in oxygen deficient silica

The properties of gamma-ray-induced absorption spectra in oxygen deficient vitreous silica were studied. The spectra were well fitted with five Gaussian absorption bands, the same bands as those found in x-ray- and excimer-laser-induced absorption spectra. Absorption intensity in oxygen deficient silica was much greater than those in silicas with Si-OH or Si-Cl units. The mechanisms for producing radiation-caused defects and the function of terminal structures such as Si-OH and Si-Cl on resisting defect formation were studied.