The influence of high temperature during electron irradiation on silica structure

This study explores the combined effects of high-dose electron irradiation and elevated temperature on Type III silica glass, focusing on its vibrational structural evolution and defect formation. A systematic investigation was carried out on both pristine and pre-densified at high pressure high temperature conditions silica samples. Electron irradiation was performed at doses up to 11 GGy, with combined heating up to 1000 K, conditions that have not been systematically studied before. Structural changes were characterized through Raman spectroscopy and photoluminescence measurements (to identify defect populations). Results show that while densification is promoted around room temperatures by irradiation, increasing the temperature above 600 K activates significant defect annealing and glass network relaxation back towards a pristine-like SiO₂ structure. These findings provide new insights into the dynamic behavior of silica under extreme conditions and help guide the design of silica-based components and sensors for high-dose, high-temperature applications, particularly in next-generation nuclear reactors.