Spatial pileup considerations for pixellated gamma-ray detectors
Spatial pileup considerations for pixellated gamma-ray detectors
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DOI：
10.1109/23.872985
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发表时间：
2000-08-01
影响因子：
1.8
通讯作者：
Barrett, HH
中科院分区：
文献类型：
--
作者：
Furenlid, LR;Clarkson, E;Barrett, HH
为伽马射线应用开发的高空间分辨率固态探测器受益于像素尺寸基本上小于探测器板厚度。这导致由于横向于漂移方向的扩散（和二次光子发射）而导致电荷部分扩散到相邻像素的可能性增强。不期望的结果是事件“尺寸”的有效放大和空间重叠问题，这是当两个光子在检测器/读出系统的积分时间内紧密接近地被吸收时导致的。我们开发了成像系统中空间堆积的一般统计数据，并将结果应用于我们正在开发的基于像素化碲锌镉（CdZnTe）和多路复用应用的探测器-专用集成电路（ASIC）读出。我们认为，对总计数率的能力和详细探讨的后果LISTMODE数据采集策略的限制。算法提出了识别，并在可能的情况下，解决重叠事件的最大似然估计。这些算法的有效性和噪声容忍度将在未来的工作中进行测试与模拟和实验数据相结合。
High-spatial-resolution solid-state detectors being developed for gamma-ray applications benefit from having pixel dimensions substantially smaller than detector slab thickness. This leads to an enhanced possibility of charge partially spreading to neighboring pixels as a result of diffusion (and secondary photon emission) transverse to the drift direction. An undesirable consequence is the effective magnification of the event "size" and the spatial overlap issues which result when two photons are absorbed in close proximity within the integration time of the detector/readout system.In this work, we develop the general statistics of spatial pileup in imaging systems and apply the results to detectors we are developing based on pixellated cadmium zinc telluride (CdZnTe) and a multiplexing application-specific integrated circuit (ASIC) readout. We consider the limitations imposed on total count rate capacity and explore in detail the consequences for the LISTMODE data-acquisition strategy. Algorithms are proposed for identifying and, where possible, resolving overlapping events by maximum-likelihood estimation. The efficacy and noise tolerance of these algorithms will be tested with a combination of simulated and experimental data in future work.