Development of a precise evaluation technique for the pre-sampled point spread function of X-ray imaging detectors with sub-micrometer resolution
Development of a precise evaluation technique for the pre-sampled point spread function of X-ray imaging detectors with sub-micrometer resolution
复制标题
开发亚微米分辨率X射线成像探测器预采样点扩散函数的精确评估技术
DOI：
10.1016/j.nima.2021.165303
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
T. Hatsui
中科院分区：
文献类型：
--
作者：
K. Nakajima;T. Kameshima;T. Hatsui
本文介绍了一种在 X 射线成像探测器的像素采样之前精确测量硅传感器内部电荷扩散的方法。以亚微米分辨率演示了硅传感器的电荷扩散或预采样点扩散函数 (PSF) 的形状。测量装置包括由同步加速器辐射源发射的准单色 X 射线束、直径为 5 μ m 的钨针孔、亚 μ m 分辨率 X 射线光束分析仪以及用于步进扫描测量的自动化模式下的光电二极管阵列。根据在 SPring-8 的 BL19LXU 上使用 7.3 keV X 射线进行的初步实验，我们获得了 16.5–17.1 μm 的值（半峰全宽；传感器厚度：650 μm；偏置电压：750 V）。该值与从光束轮廓和预采样 PSF 的卷积获得的预期值一致，该 PSF 对应于在大约 1 μ m 范围内掺杂剂密度为～ 1 0 12 cm− 3 的多个光子。我们相信我们的测量方法有足够的潜力来评估光电二极管阵列的预采样 PSF，精度为 1 μm 或更小。成像探测器的单光子能力取决于探测器噪声以及预采样的PSF。我们的测量方法具有高空间分辨率，在使用像素数量有限的样本片优化 X 射线图像传感器的像素设计方面是有益的。
This article presents a method for precisely measuring the charge spread inside a silicon sensor, before it is sampled by the pixels of an X-ray imaging detector. The shape of the charge spread or pre-sampled point spread function (PSF) of the silicon sensor was demonstrated with a sub-micrometer resolution. The measurement setup comprises quasi-monochromatic X-ray beams emitted by a synchrotron radiation source, 5-μ m-diameter tungsten pinhole, sub-μ m-resolution X-ray beam profiler, and photodiode array in automation mode for step-scanning measurements. We obtained a value of 16.5–17.1 μ m (full width at half-maxima; sensor thickness: 650 μ m; bias voltage: 750 V) based on preliminary experiments using 7.3 keV X-rays at BL19LXU of SPring-8. This value is consistent with the expected value obtained from the convolution of the beam profiles and pre-sampled PSFs corresponding to multiple photons for a dopant density of∼ 1 0 12 cm− 3 within a range of approximately 1 μ m. We believe that our measurement method has sufficient potential for evaluating the pre-sampled PSF of a photodiode array with an accuracy of 1 μ m or less. The single-photon capability of imaging detectors depends on the detector noise as well as the pre-sampled PSF. Our measurement method, with high spatial resolution, is beneficial in the sense that it optimizes the pixel design of X-ray image sensors using a sample piece with a limited number of pixels.
影响因子：
35
作者：
Ackermann, W.;Asova, G.;Zapfe, K.
通讯作者：
Zapfe, K.