超高密度Ce3+激活硼锗碲酸盐闪烁玻璃制备及其发光性能研究

高密度闪烁玻璃因化学组份易调、尺寸与形状可控、光学均匀性好、方法简单及成本低廉等优势有望取代商用闪烁晶体，应用于高能物理实验与核医学成像等工程领域。但现有Ce3+激活高密度闪烁玻璃因吸收边红移诱导的严重自吸收降低了其光产额，进而产生“高密度闪烁玻璃光产额普遍较低”现象，限制了其广泛应用。本项目以硼锗碲三元系玻璃为网络形成体，通过富含稀土化合物（40-55 mol%）获得紫外截止波长较短、密度超过7.0 g/cm3的Ce3+激活硼锗碲酸盐闪烁玻璃。利用光谱技术并结合发光理论、光碱度理论和晶场理论分析玻璃中稀土离子间的能量传递效率、发光效率与其掺杂浓度的关系。利用现代材料表征技术系统研究Ce3+激活硼锗碲酸盐闪烁玻璃微结构与发光性能间构效关系，并综合评估硼锗碲酸盐闪烁玻璃的光学透过率、光产额、衰减时间、余辉、能量分辨率、能量响应及辐照硬度等闪烁性能，为获得实际应用的高性能闪烁玻璃奠定科学基础。

Dense scintillating glasses, with the advantages of versatile composition, controllable size and shape (including fiber), excellent optical homogenization, simple preparation technology and relatively low production cost, have been a crucial candidate for commercial scintillating crystals in the engineering fields of high-energy physics experiment and medical imaging. However, the available dense fluoride and oxide scintillating glasses with the relatively longer cut-off edges have been usually strictly limited to a few applications owing to the lower light yield or zero light yield, which results from the heavy self-absorption of cerium ions. In this project, the superdense Ce3+-acitvated borogermanate-tellurite scintillating glass consisting of both glass networks (B2O3, GeO2 and TeO2) and modifier (40-55 mol% of RE2O3 and REF3) is expected to be featured with the shorter cut-off edge, higher density of over 7.0 g/cm3, and brighter radiouluminescence intensity. The relationship among energy transfer efficiency, luminescence efficiency and the concentration of the rare-earth ions in borogermanate-tellurite scintillating glass will be investigated based on the luminescence, optical basicity, crystal field theories, together with the spectral data. Moreover, the relationship between the microstructure and the corresponding scintillation properties of Ce3+-activated borogermanate-tellurite glass will be revealed in detail by material characterization methods. The overall scintillation properties including optical transmittance, light output, decay time, afterglow, energy resolution, energy response and radiation-resistance will be finally evaluated and compared with the standard BGO scintillating crystal. All that done is aimed to make a solid scientific foundation for the practical application of the studied superdense Ce3+-activated borogermanate-tellurite scintillating glass.