富集10B的Ce:Li6Lu(10BO3)3晶体生长及其闪烁性能

为了提高中子探测效率, 以富集¹⁰B的H₃¹⁰BO₃为原料, 通过提拉法生长了富集¹⁰B的Ce:Li₆Lu(¹⁰BO₃)₃晶体。X射线激发发射光谱测试表明: 其发光峰位于360~480 nm, 属于Ce³⁺离子典型的5d - 4f跃迁发光, 其闪烁发光效率为BGO晶体的3.9倍。在350 nm紫外光和¹³⁷Cs所发出的662 keV的γ射线激发下测得的衰减时间分别为21.0 ns 和31.7 ns, 在¹³⁷Cs辐射源激发下所测得的相对光输出是CsI(Tl)晶体的20%, 能量分辨率为9.7%。在慢化²⁵²Cf中子源激发下可以观测到明显的中子全能峰, 其能量分辨率为33%。上述研究结果表明, Ce:Li₆Lu(¹⁰BO₃)₃晶体具有较高的闪烁效率、快的衰减时间和良好的中子探测效率, 是一种具有应用前景的中子探测用闪烁晶体。

Growth and Scintillation Properties of Ce:Li6Lu(10BO3)3 Crystal

To improve the neutron detection efficiency, Ce:Li₆Lu(¹⁰BO₃)₃ crystal was grown by Czochralski method from the raw materials enriched with ¹⁰B isotopes. The X-ray excited luminescence of Ce:Li₆Lu(¹⁰BO₃)₃ crystal presents an emission band from 360 nm to 480 nm corresponding to 5d - 4f transitions of Ce³⁺ ions. The scintillation efficiency of Ce:Li₆Lu (¹⁰BO₃)₃ crystal was 3.9 times as large as that of BGO crystal, and the photoluminescence decay time excited by 350 nm and scintillation decay time excited by ¹³⁷Cs γ-ray source were 21.0 ns and 31.7 ns, respectively. The relative light output of Ce:Li₆Lu(¹⁰BO₃)₃ crystal excited with 662 keV γ-ray from ¹³⁷Cs was 20% that of CsI(Tl) crystal and the energy resolution was measured to be 9.7%. In the neutron energy spectrum excited by moderated ²⁵²Cf neutron source, the obvious full energy peak of neutron was observed and the energy resolution was 33%. With the relatively high scintillation efficiency, fast decay time and good neutron detection efficiency, Ce:Li₆Lu(¹⁰BO₃)₃ crystal is a promising fast scintillator for neutron detection applications.