Scintillators With Potential to Supersede Lanthanum Bromide
Scintillators With Potential to Supersede Lanthanum Bromide
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DOI：
10.1109/tns.2009.2020165
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发表时间：
2009-06-01
影响因子：
1.8
通讯作者：
Moses, William W.
中科院分区：
文献类型：
--
作者：
Cherepy, Nerine J.;Payne, Steve A.;Moses, William W.
用于高分辨率伽马射线光谱学的新的闪烁体已经被识别、生长和表征。我们的开发工作主要集中在两类高光产率材料：掺铕碱土金属卤化物和掺铈石榴石。在我们用布里奇曼法生长的卤化物单晶中，SrI_2、CaI_2、SrBr_2、BaI_2和BaBr_2-SrI_2是最有前途的。SrI 2（Eu）发射到Eu 2+带，中心在435 nm，具有1.2 μ s的衰减时间和高达115，000光子/MeV的光产额。它在662 keV下提供优于3% FWHM的能量分辨率，并具有出色的光产额比例。透明陶瓷制造允许生产钆基和铽基石榴石，其由于相不稳定性而不能通过熔融技术生长。铈掺杂的陶瓷石榴石的闪烁光产额很高，20，000 - 100，000光子/MeV。我们正在发展的机制的能量依赖闪烁光产额不成比例的理解，以及它如何影响能量分辨率。我们还确定了光学设计的方面，可以优化，以提高能量分辨率。
New scintillators for high-resolution gamma ray spectroscopy have been identified, grown and characterized. Our development efforts have focused on two classes of high-light-yield materials: europium-doped alkaline earth halides and cerium-doped garnets. Of the halide single crystals we have grown by the Bridgman method-SrI2, CaI2, SrBr2, BaI2 and BaBr2-SrI2 is the most promising. SrI2 (Eu) emits into the Eu2+ band, centered at 435 nm, with a decay time of 1.2 mu s and a light yield of up to 115,000 photons/MeV. It offers energy resolution better than 3% FWHM at 662 keV, and exhibits excellent light yield proportionality. Transparent ceramic fabrication allows the production of gadolinium- and terbium-based garnets which are not growable by melt techniques due to phase instabilities. The scintillation light yields of cerium-doped ceramic garnets are high, 20,000-100,000 photons/MeV. We are developing an understanding of the mechanisms underlying energy dependent scintillation light yield non-proportionality and how it affects energy resolution. We have also identified aspects of optical design that can be optimized to enhance the energy resolution.