Dosimetric properties of europium, gadolinium and cerium borosilicate glasses in application of electron beam dose measurements

Dosimetric properties of the borosilicate glasses (SiO₂–B₂O₃–Al₂O₃–CaO–Na₂O type) doped with Eu₂O₃, Gd₂O₃ and CeO₂ rare earth oxides were investigated as potential materials for e-beam radiation dose measurement purposes. Glasses were prepared by classical melt-quench methodology with varying concentration of rare earth metal oxides from 0.5% to 1.5%. Linear electron accelerator was used for irradiation (17 ns or 4 μs duration pulsed mode). For lower dose range investigated (up to 900 Gy) all samples studied exhibit good dosimetric response vs. dose absorbed, whereas for higher dose range (up to 30 kGy), only materials doped with 0.5% and 1.5% of Gd₂O₃, as well as 0.5% CeO₂ doped glasses were able to provide reproducible dosimetric response. Significant dose sensitivity variation was observed for all investigated glasses, which was dependent both on the rare earth metal concentration and the dose rate of radiation used for signal generation. For irradiated 0.5% Eu₂O₃, Gd₂O₃ and CeO₂ doped glasses spectrally-resolved thermoluminescence measurements were performed. Results suggest different traps formation and stabilization mechanisms for each dopant, indicating Eu³⁺→Eu²⁺ ions reduction with simultaneous traps number consumption, glass network modification and traps stabilization for Gd₂O₃ doped glass and direct reduction of Ce⁴⁺→Ce³⁺ with simultaneous glass network disruption and increasing number of low energy traps. All investigated glass samples can be considered as potential dosimetric materials for electron beam delivered dose within the dose range up to 900 Gy and with some limitations, regarding higher doses up to 15 kGy.