Cs_2NaGdBr_6∶Ce单晶生长及闪烁性能研究

Study on Growth and Scintillation Properties of Cs_2NaGdBr_6∶Ce Single Crystal

Cs_2NaGdBr_6∶Ce(CNGB∶Ce)是新近发现的性能优异的闪烁晶体,本文用Bridgman法成功制备出尺寸达Φ25×25 mm^3的CNGB∶Ce单晶,并测试了CNGB∶Ce晶体的相关闪烁性能。荧光光谱和X射线激发发射光谱测试结果表明CNGB∶Ce晶体主要有两个发射峰,分别位于383 nm和418 nm附近,分别对应于Ce^(3+)的5d→4f^(12)F_(5/2)和5d→4f^(12)F_(7/2)跃迁发射。γ射线能谱测试表明CNGB∶Ce晶体的光输出约为LaBr_3∶Ce晶体的2/3,在662 ke V处的能量分辨率为6.2%,衰减时间为76 ns左右,这些特点使得CNGB∶Ce晶体有望成为实用化的新型闪烁晶体。

Cs2NaGdBr6∶Ce（ CNGB ∶ Ce） isa newly discovered scintillation crystal with excellentproperties. Single crystal of CNGB∶ Ce with dimensions up to Φ25 mm × 25 mm were successfully grown through the Bridgman method. The luminescence and scintillation characterizations of CNGB ∶ Ce single crystal were presented. Under UV and X-ray excitation, the CNGB ∶ Ce sample crystals exhibitedcerium double emission peaks located around 383 nm and 418 nm,corresponding to Ce^3＋5d→4f12F5 /2 and 5d → 4f 12F7 /2 transmission,respectively. γ-ray spectroscopy measurements revealsthat the lightoutput of CNGB∶ Ce is about 2 /3 times ofcalibrated LaBr3∶ Ce single crystal. The energy resolutions of the CNGB ∶ Ce crystal at 662 ke V is 6. 2%. The decay time is fitted to be about 76 ns. Those properties make it possible for CNGB∶ Ce crystal to become a new practical scintillation crystal.