Sub-pixel resolution of a pnCCD for X-ray white beam applications
Sub-pixel resolution of a pnCCD for X-ray white beam applications
复制标题
用于 X 射线白光束应用的 pnCCD 的亚像素分辨率
DOI：
10.1088/1748-0221/8/05/p05005
复制
发表时间：
2013
影响因子：
1.3
通讯作者：
U. Pietsch
中科院分区：
文献类型：
--
作者：
A. Abboud;S. Send;N. Pashniak;W. Leitenberger;S. Ihle;M. Huth;R. Hartmann;L. Strüder;U. Pietsch
针对X射线单光子计数模式的应用，提出了一种实现75×75μm2像素的pnCCD亚像元空间分辨率的新方法。该方法以矩形电荷云密度模型为基础，考虑了单个光子产生的电荷云的能量依赖性及其在探测器相邻像素之间的分裂概率。对于这种云的电荷分布在3个或4个像素上的情况，可以以优于2μm的精度重建光子碰撞的中心位置。预测的电荷云大小在选定的X射线荧光线上进行检验，分别发射能量在6.4keV到17.4keV之间以及形成尺寸(均方根)在8μm到10μm之间变化的电荷云。通过在整个光纤光栅上的X射线传输实验，验证了pnCCD2μm空间分辨率的提高。
A new approach to achieve sub-pixel spatial resolution in a pnCCD detector with 75 × 75 μm2 pixel size is proposed for X-ray applications in single photon counting mode. The approach considers the energy dependence of the charge cloud created by a single photon and its split probabilities between neighboring pixels of the detector based on a rectangular model for the charge cloud density. For cases where the charge of this cloud becomes distributed over three or four pixels the center position of photon impact can be reconstructed with a precision better than 2 μm. The predicted charge cloud sizes are tested at selected X-ray fluorescence lines emitting energies between 6.4 keV and 17.4 keV and forming charge clouds with size (rms) varying between 8 μm and 10 μm respectively. The 2 μm enhanced spatial resolution of the pnCCD is verified by means of an x-ray transmission experiment throughout an optical grating.