Inclusion of a Charge Sharing Correction Algorithm Into an X-Ray Photon Counting Spectral Detector Simulation Framework
Inclusion of a Charge Sharing Correction Algorithm Into an X-Ray Photon Counting Spectral Detector Simulation Framework
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DOI：
10.1109/trpms.2020.3008861
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发表时间：
2021-07-01
影响因子：
4.4
通讯作者：
Darambara, D. G.
中科院分区：
文献类型：
--
作者：
Pickford Scienti, O. L. P.;Bamber, J. C.;Darambara, D. G.
大多数光子计数光谱成像 (x-CSI) 模拟结合了蒙特卡罗技术和实验测量来模拟信号输出。这些通常会省略一些物理过程，以最大限度地减少所需的计算资源，从而获得比实验更高的模拟能量分辨率。未模拟过程的总体效应可以使用实验得出的“模糊”因素进行补偿。模糊因子通常采用模拟输出的高斯卷积的形式来模拟系统噪声和收集效率低下。然而，这种方法并不适合涉及电荷共享校正算法 (CSCA) 建模的应用，因为大多数 CSCA 在预阈值域中运行并跨多个像素，包含不同数量的噪声和收集效率。为了更好地模拟 x-CSI CSCA，这项工作引入了 CoGI：一个结合蒙特卡罗和有限元方法的框架，用于模拟光子-物质相互作用、像素内电荷传输、像素间电荷共享、信号生成和 CSCA。 CoGI 是文献中报道的第一个包含 CSCA 的完整 x-CSI 模拟框架。 CoGI 已分别使用伽马射线光谱仪和 Acteon 系列像素化 x-CSI 探测器在光谱和能量分档模式下进行了验证。因此，CoGI 代表了一个用于比较多个基于 ASIC 的 CSCA 的通用框架，并将有助于为未来的 x-CSI 系统开发提供信息。
Most photon counting spectral imaging (x-CSI) simulations combine Monte Carlo techniques and experimental measurements to model signal output. These often omit some physical processes to minimize the computational resources needed, resulting in higher simulated energy resolutions compared with experiments. The aggregate effect of unsimulated processes can be compensated for using experimentally derived "blurring" factors. Blurring factors usually take the form of Gaussian convolutions of the simulation output to model system noise and collection inefficiencies. This approach is not suitable for applications involving charge sharing correction algorithm (CSCA) modeling, however, as most CSCAs operate in the prethresholding domain and across multiple pixels, incorporating variable amounts of noise and collection efficiency. To better model x-CSI CSCAs, this work introduces CoGI: a framework combining Monte Carlo and finite element methods to simulate photon-matter interaction, intrapixel charge transport, interpixel charge sharing, signal generation, and CSCA. CoGI is the first full x-CSI simulation framework to incorporate CSCA reported in the literature. CoGI has been validated in spectral and energy binning modes, using a gamma-ray spectrometer and an Acteon series pixelated x-CSI detector, respectively. CoGI thus represents a versatile framework for comparing multiple ASIC-based CSCAs and will help inform future x-CSI system development.