THERMOLUMINESCENCE PROPERTIES OF THE 0.5P₂O₅ - xBaO - (0.5-x)K₂O GLASS SYSTEM. A POSSIBLE DOSIMETRIC MATERIAL

Abstract

Thermoluminescence (TL) properties of freshly b irradiated phosphate glasses doped with BaO and K₂O oxides at various concentrations were investigated. Barium-doped glasses (0.5P₂O₅ -  0.5BaO) show two TL peaks  centered at 180 ⁰C and 380 ⁰C due to the defects generated by modifier Ba²⁺ ions inserted into the glass network. In the case of potassium-doped glasses (0.5P₂O₅ - 0.5K₂O) an intense TL peak at 280 ⁰C with an weak shoulder at 150 ⁰C appear. The TL emission of the other phosphate glasses, 0.5P₂O₅ -  xBaO - (0.5-x)K₂O with 0.1 £ x £ 0.4, containing both type of the network modifier ions (K⁺, Ba²⁺) consist from the overlap of the above – mentioned luminescence spectra depending on the local energetic level diagrams of the luminescence centers. A linear dependence (R² > 0.99) of the integral TL signals with the absorbed doses were evidenced for all the investigated glasses which can be considered as good materials for dosimetry in the 0 – 50 Gy range.