Analogous Lubberts effect in photon counting detectors.
Analogous Lubberts effect in photon counting detectors.
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光子计数探测器中的类似鲁伯特效应。
DOI：
10.1117/12.2549785
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Li,Ke
中科院分区：
文献类型：
--
作者：
Li,Ke
对于由X射线-闪烁体相互作用产生的光突发，光量子的准各向同性扩展决定了光突发的光收集效率和扩展函数都取决于相互作用的深度(Z)：光突发的初始位置离光传感器越近，探测器系统遇到的光损失和空间分辨率劣化就越小。对于基于闪烁体的间接转换探测器，X射线转换增益和MTF沿z方向的变化对DQE损失有很大贡献，被称为Lubberts效应。了解效应背后的物理机制并开发减少效应的解决方案，使间接转换探测器的性能得到了极大的改善。相比之下，对于直接转换光子计数探测器(PCD)，由于不涉及光量子的产生或输运，因此不存在经典的Lubberts效应。然而，半导体中产生的载流子的输运性质确实取决于它们的旅行距离。因此，直接转换检测器的性能可能取决于z。这种依赖可以被认为是经典吕伯茨效应的对应物。这项工作的目的是分析各种物理机制的贡献，这些机制可能有助于直接转换PCD中的类Lubberts效应。结果表明，类Lubberts效应主要是由深度相关的电荷俘获和复合几率引起的。在物理分析的基础上，可以优化PCD电极的设计，使类Lubberts效应和相关的DQE损耗最小化。
For a light burst generated by an x ray-scintillator interaction, the quasi-isotropic spreading of optical quanta determines that both the light collection efficiency and the spread function of the light burst depend on the depth (z) of interaction: the closer the initial position of light burst to the light sensor, the less light loss and spatial resolution degradation a detector system encounters. For scintillator-based indirect-conversion detectors, the variation of the x-ray conversion gain and the MTF along thezdirection contributes to a significant fraction of DQE loss and is known as the Lubberts effect. Understanding the physics behinds the effect and developing solutions to reduce the effect have led to tremendous improvements in the performance of indirect-conversion detectors. In contrast, for direct-conversion photon counting detectors (PCDs), since no optical quanta generation or transport is involved, there is no classical Lubberts effect. However, the transport properties of the generated charge carriers in semiconductors do depend on their travel distance. As a result, the performance of direct conversion detectors may depend onz. This dependence can be considered as a counterpart of the classical Lubberts effect. The purpose of this work is to analyze the contributions of a variety of physical mechanisms that may contribute to a Lubberts-like effect in direct-conversion PCDs. The results show that the Lubberts-like effect is primarily caused by the depth-dependent charge trapping and recombination likelihood. Based upon the physics analysis, PCD electrode design can be optimized to minimize the Lubberts-like effect and the associate DQE loss.
影响因子：
3.8
作者：
Badano, A;Gagne, RM;Myers, KJ
通讯作者：
Myers, KJ
使用单 X 射线光子成像直接测量 CsI:Tl 闪烁体中的鲁伯特效应
影响因子：
--
作者：
A. Howansky;A. Lubinsky;S. Ghose;Katsuhiko Suzuki;Wei Zhao
通讯作者：
Wei Zhao
有限磷光体厚度对探测量子效率的影响。
影响因子：
3.8
作者：
R. Nishikawa;M. Yaffe;R. Holmes
通讯作者：
R. Holmes