Influences of Thermal Annealing Temperatures on Irradiation Induced E′ Centers in Silica Glass

Influences of pre-irradiation and thermal annealing on E' defect concentration are studied by measuring E' centers and optical absorptions using ESR and spectrophotometer, respectively. The results show that the E' defect concentration decreases significantly when silica glass is pre-irradiated by gamma rays and a subsequent thermal annealing. The effect of thermal annealing on the E' concentration has also been investigated for the temperature from 300 degrees C to 1300 degrees C. It is found from the ESR spectrum that the anti-irradiated property or the silica glass can be improved when the thermal annealing temperature is larger than 700 degrees C. These results have been proved by optical absorption spectra.