卤化物闪烁晶体研究进展

Research Advances in Halide Scintillation Crystals

闪烁晶体作为重要的辐射探测材料,在核医学、高能物理、安全检查等诸多领域有着广泛应用。近年来,一系列性能优异的新型卤化物闪烁晶体相继涌现,使卤化物型闪烁晶体成为本领域的研究热点。本文对当前几种不同类型的卤化物闪烁晶体的研究情况进行了综述,重点介绍了以LaBr_3∶Ce为代表的REX_3∶Ce型稀土卤化物闪烁晶体,以SrI_2∶Eu为代表的MX_2∶Eu型碱土金属卤化物闪烁晶体,以及以Cs_2LiYCl_6∶Ce为代表的Ce^(3+)激活的复合稀土卤化物型闪烁晶体的研究进展情况。这些晶体普遍具有高光输出、高能量分辨率等优点,但也都存在易潮解、成本高、大尺寸单晶生长困难等问题。晶体生长用高纯无水卤化物原料的制备技术是当前制约卤化物闪烁晶体产业发展的关键技术。该技术有望在近年内获得突破并有力促进上述卤化物闪烁晶体的实际应用。

Scintillation crystals are important radiation detection materials which are widely used in nuclear medicine, high energy physics, security inspection and various other fields. In recent years, a series of novel halide scintillation crystals with excellent scintil- lation properties were developed, which made halides the new research hotspot in this field. This paper reviewed recent advances of several different types of halide scintillation crystals, including REX3 ： Ce-type rare earth halide crystals represented by LaBr3 ： Ce, MX2 ： Eu-type alkaline earth halide crystals represented by SrI： ： Eu, and Ce3 ＋ activated rare earth complex halide crystals represented by Cs2 LiYC16 ： Ce. All these halide crystals showed merits of high light yield and good energy resolution, but they also suffered from the drawbacks of hygroscopicity and high cost, and had difficulty in growing large single crystals. Lack of an efficient technique to prepare high purity anhydrous metal halides as raw materials for crystal growth was the key factor that currently restrained the development of these halide scintillation crystals. However, this problem was expected be solved in the near future, which might greatly promote the application of these crystals.