Dosimetric properties of lithium magnesium borate glasses doped with dysprosium and phosphorus oxide for radiation dose measurement

Abstract

Series of lithium and magnesium oxide modified borate glasses of compositions 30Li2O – (70 – x) B2O3 – xDy2O3 where 0 = x = 1 mol % (LB:Dy), 20Li2O – 10MgO – (70-x) B2O3 – xDy2O3 where 0.3 = x = 1 mol % (LMB:Dy) and 20Li2O – 10MgO – (69.5 – x) B2O3 – 0.5Dy2O3 – xP2O5 where 0.5 = x = 2 mol % (LMB:Dy,P) were prepared using melt-quenching method. The present study was performed with the aim of improving the thermoluminescence (TL) properties of lithium borate glass. The prepared glass samples were characterized by X-Ray diffraction (XRD) and differential thermal analysis (DTA). The room temperature photoluminescence (PL) emission spectra of the glass series at 350 nm excitation consist of two peaks centered at 481 nm and 573 nm corresponding to the transitions (4F9/2 ? 6H15/2) and (4F9/2 ? 6H13/2), respectively. The TL glow curves of LB:Dy (0.5 mol %) revealed a single prominent peak at a maximum temperature (Tm) of 190 °C. An enhancement of TL response about 1.4 times was observed with the presence of MgO as a second modifier to lithium borate. The addition of P2O5 as co-dopant into LMB:Dy (0.5 mol %) enhanced the TL intensity by a factor of 2.2, with the increase of P2O5 concentration up to 1 mol % and quenching effects occurred beyond this concentration value. LMB:Dy,P was found to have a good effective atomic number (Zeff=9.05), linear dose response up to 100 Gy and showed a higher TL response compared to LMB:Dy and LB:Dy. The study of fading characteristic showed that LMB:Dy,P glass has lower fading compared to LMB:Dy and LB:Dy. The trap parameters, including the order of kinetics, activation energy (E) and frequency factor (s) for the glass samples were also determined. In conclusion, the prepared glasses have potential as a thermoluminescence material for radiation monitoring and dose measurement.