Terahertz time-domain spectroscopy (THz-TDS) is demonstrated to be effective in novel application, for 3D characterization of wrapped scintillator crystals in search for defects affecting the light-yield of these crystals. This is of special importance for fast scintillators currently in demand to be exploited in high-energy physics experiments and medical imaging devices. Typical inorganic (GAGG:Ce) and organic (BC-408) scintillators wrapped in polytetrafluoroethylene (PTFE) and enhanced specular reflector (ESR) tapes have been studied. Time-of-flight information extracted from THz-TDS data reveals positions of the interfaces between the materials, wrapping thickness variations, and allows for the wrapping inspection with resolution better than a single layer, typically ∼200 μm-thick, of PTFE, the currently most common wrapping material. The results are supported by the study of the properties of the wrapping materials in the THz range and evidence of the prospectiveness of THz-TDS technique as a novel tool for nondestructive inspection of wrapped scintillators.

中文翻译：

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太赫兹断层扫描，用于检测包裹的闪烁晶体


太赫兹时域光谱 （THz-TDS） 被证明在新的应用中是有效的，用于包裹闪烁体晶体的 3D 表征，以寻找影响这些晶体光产率的缺陷。这对于目前需要用于高能物理实验和医学成像设备的快速闪烁体尤为重要。已经研究了包裹在聚四氟乙烯 （PTFE） 和增强型镜面反射器 （ESR） 带中的典型无机 （GAGG：Ce） 和有机 （BC-408） 闪烁体。从 THz-TDS 数据中提取的飞行时间信息揭示了材料之间界面的位置、包装厚度的变化，并允许以优于单层 PTFE（通常为 ∼200 μm 厚）的分辨率进行包装检查，PTFE 是目前最常见的包装材料。对包装材料在 THz 范围内的性能的研究以及 THz-TDS 技术作为包裹闪烁体无损检测新工具的前景的证据支持了这一结果。