Abstract
Electron paramagnetic resonance (EPR) studies have been carried out on KU1 fused silica irradiated with neutrons at fluences 10 21 and 10 22 n/m 2, and gamma-ray doses up to 12 MGy. The effects of post-irradiation thermal annealing treatments, up to 850 °C, have also been investigated. Paramagnetic oxygen-related defects (POR and NBOHC) and E′-type defects have been identified and their concentration has been measured as a function of neutron fluence, gamma dose and post-irradiation annealing temperature. It is found that neutrons at the highest fluence generate a much higher concentration of defects (mainly E′ and POR, both at concentrations about 5 × 10 18 spins/cm 3) than gamma irradiations at the highest dose (mainly E′ at a concentration about 4 × 10 17 spins/cm 3). Moreover, for gamma-irradiated samples a lower treatment temperature (about 400 °C) is required to annihilate most of the observed defects than for neutron-irradiated ones (about 600 °C).
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
