基质组分配比对Cs2LiYCl6∶Ce晶体生长及闪烁性能的影响

Cs₂LiYCl₆∶Ce(CLYC∶Ce)是一种具有良好能量分辨率、高光输出,以及优秀的中子/伽马分辨能力的新型闪烁晶体,但因其组分复杂,晶体生长很困难。本文使用坩埚下降法分别生长了LiCl占57%、60%和63%(摩尔分数)及CsCl与YCl₃比例为1.9∶1和2.1∶1共5种不同组分配比的CLYC晶体,发现LiCl占比为60%的组分得到的CLYC相体积占比最大,而改变CsCl与YCl₃的比例对晶体生长没有明显的积极作用。5 mm×5 mm×5 mm和φ25 mm×10 mm样品在¹³⁷Cs激发下的能量分辨率分别为4.8%和5.6%。CLYC晶体在662 keV伽马射线激发下的闪烁衰减时间为17 ns、436 ns和3 603 ns。

Effect of Matrix Composition Ratio on the Growth and Scintillation Properties of Cs2LiYCl6:Ce Crystal

Cs₂LiYCl₆:Ce (CLYC:Ce) is a new type of scintillation crystal with good energy resolution, high light output and excellent neutron/gamma discrimination ability. However, its complex composition results in many difficulties for crystal growth. In this paper, five different CLYC crystals with different composition ratios of LiCl accounted for 57%, 60% and 63% (mole fraction) and CsCl to YCl₃ ratios of 1.9:1 and 2.1:1 were grown using the vertical Bridgman method. It is found that optimal proportion for high quality CLYC is 60% LiCl, where the volume ratio of transparent CLYC phase to the total ingot is the largest. Changing the ratio of CsCl to YCl₃ has no obvious positive effect on crystal growth. The energy resolution of 5 mm×5 mm×5 mm and φ25 mm×10 mm samples excited by ¹³⁷Cs is 4.8% and 5.6%, respectively. The scintillation decay time of CLYC crystal under 662 keV gamma-ray excitation is 17 ns, 436 ns and 3 603 ns.