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根据美国ＳＬＡＣ公司及日本ＫＥＫ公司的要求，我们为其提供高能探测器所需的大尺寸掺铊碘化铯晶体。他们对晶体性能提出了较高的要求，要求晶体透明不着色、无云层和杂质包裹体等缺陷。由于这些缺陷的存在会导致晶体光输出下降、均匀性变差、抗辐照损伤能力下降、甚至出现开裂而影响晶体的质量。但这些缺陷在生长过程中又不可避免，为此我们对这些缺陷进行了深入的研究。在卤化物晶体生长过程中，氧的存在哪怕是ｐｐｍ级的含量都会对生长带来危害，造成晶体性能下降，所以大多采用在真空状态下生长。对于掺铊的碘化铯晶体国外更是全部采用在真空状态下生长，而我们根据掺铊碘化铯晶体的生长特性采用不同于国外的真空炉生长而使用大气下坩埚下降法，且又不同于一般的坩埚下降生长法。在我们的工艺条件下主要产生上述三种缺陷，本文阐述了这些缺陷的形成和危害。其中晶体的着色表现为顶部泛黄，这主要是生长过程中来源于水分和外界空气中氧的进入。虽然我们在装料过程中采用了真空处理，然而仍不可避免氧的进入。晶体生长是排杂过程，氧离子作为阴离子杂质不断向上排，在顶部富集与铊离子结合从而使晶体顶部发黄。同样，云层也出现在晶体的上半部，但它的产生是由于温场变化而引起。主要是加热功率起伏?
According to the requirements of American SLAC Company and Japanese KEK Company, we provide them with the large size of thallium-doped cesium iodide crystals needed by high-energy detectors. They put forward higher requirements on the performance of the crystal, requiring the crystal to be transparent and not colored, and free of defects such as clouds and impurity inclusions. Due to the existence of these defects, the light output of the crystal will be decreased, the uniformity will be deteriorated, the ability of anti-radiation damage will be reduced, and even the cracking will affect the quality of the crystal. However, these defects in the growth process is inevitable, for which we have conducted an in-depth study of these defects. In the process of halide crystal growth, the presence of oxygen, even if it is in the ppm level, will bring harm to the growth and cause the crystal performance to decline. Therefore, the growth is mostly performed in a vacuum state. For the thallium-doped cesium iodide crystals abroad are all used in vacuum growth, and we based on the growth characteristics of thallium-doped cesium iodide crystals using different vacuum furnace growth abroad and the use of atmospheric crucible down method, and different In the general crucible down growth method. In our process conditions mainly produce the above three defects, this article describes the formation of these defects and hazards. Among them, the coloring of the crystal is yellowing at the top, which is mainly due to the moisture and the oxygen in the outside air during the growth. Although we used vacuum in the charging process, it is still inevitable that oxygen will enter. Crystal growth is a process of exclusion. Oxygen ions continue to rise up as anion impurities, enriching with the thallium ions at the top and yellowing the top of the crystals. Similarly, clouds also appear in the upper half of the crystal, but its production is due to changes in the temperature field. Mainly heating power fluctuations?