Y3+/Li+和Y3+/Na+双掺杂氟化钡快响应闪烁晶体

氟化钡(BaF₂)晶体是已知响应最快的闪烁晶体,在高能物理、核物理及核医学等领域有着广泛的应用前景。抑制BaF₂晶体的慢发光成分对其工程应用至关重要。本文利用坩埚下降法制备了高Y³⁺掺杂浓度5%、8%、10%(摩尔分数)的BaF₂晶体,并采用Y³⁺与碱金属离子(Li⁺、Na⁺)共掺杂的方法形成电荷补偿阻止间隙F^-的产生,制备了双掺杂型BaF₂快响应闪烁晶体,进而基于优化的5 ns和2 500 ns时间门宽测试方法,研究了Y³⁺掺杂浓度以及Y³⁺与碱金属离子(Li⁺、Na⁺)共掺杂浓度对BaF₂闪烁晶体快/慢成分比的影响规律。结果表明,生长的高浓度Y³⁺掺杂BaF₂晶体的光学质量优异,在220 nm和300 nm处透过率分别高于90%和92%;随着Y³⁺掺杂浓度由0提高至10%,BaF₂晶体的慢发光成分显著降低,快/慢成分比由0.15提高至1.21;生长的Y³⁺/Li⁺及Y³⁺/Na⁺共掺杂BaF₂晶体的慢发光成分较Y³⁺掺杂BaF₂晶体进一步降低,快/慢成分比最高分别可达1.63和1.61。研制的双掺杂BaF₂快响应闪烁晶体有望应用于高能物理、核物理前沿实验等重要领域。

Y3+/Li+ and Y3+/Na+ Co-Doped Barium Fluoride Fast Response Scintillation Crystal

Barium fluoride (BaF₂) crystal is known as the fastest scintillation crystal, which has a wide application prospect in high energy physics, nuclear physics and nuclear medicine. It is very important to suppress the slow luminescence component of BaF₂ crystal for its engineering application. BaF₂ crystals with high Y³⁺ doping concentration 5%, 8%, 10% (mole fraction) were prepared by Bridgman method, and the co-doped BaF₂ fast response scintillation crystals were prepared by co-doping Y³⁺ with alkali metal ions (Li⁺, Na⁺) to form charge compensation to eliminate the generation of interstitial F^-. Then, based on the optimized 5 ns and 2 500 ns time gate width measurement methods, the effects of Y³⁺ doping concentration and the co-doping concentration of Y³⁺ and alkali metal ions (Li⁺, Na⁺) on the fast/slow component ratio of BaF₂ scintillation crystal were studied. The results show that the optical quality of the high concentration Y³⁺ doped BaF₂ crystals is excellent, and the transmittance at 220 nm and 300 nm is higher than 90% and 92%, respectively. With the increase of Y³⁺ doping concentration from 0 to 10%, the slow luminescence component of BaF₂ crystal decrease significantly, and the fast/slow component ratio increase from 0.15 to 1.21. The slow luminescence component of the grown Y³⁺/Li⁺ and Y³⁺/Na⁺ co-doped BaF₂ crystals are further decrease compared with that of the Y³⁺ doped BaF₂ crystals, and the highest fast/slow component ratios obtained are 1.63 and 1.61, respectively. The co-doped BaF₂ fast response scintillation crystal is expected to be applied in the frontier experiments of high energy physics and nuclear physics.