The present study focuses on the implementation of two X-ray phase contrast imaging (XPCI) techniques: free-space propagation (FSP) and single mask edge illumination (SM-EI) with a microfocus polychromatic X-ray source and a Timepix3 photon-counting detector with a CdTe sensor. This detector offers high spatial resolution, high detection efficiency and it is able to simultaneously record information about Time-over-Threshold (ToT) and Time-of-Arrival (ToA) for each X-ray photon. All these features play a key role in enabling an improvement of XPCI image quality, especially through spectral analysis, since it is possible to measure the energy of each incident X-ray photon. Measurements of phase contrast and contrast-to-noise ratio (CNR) are presented for different energy bins within the typical spectrum of soft X-ray imaging. It is shown that a significant enhancement of XPCI image quality can be obtained, for both implemented techniques, by performing pixel clustering to correct for charge sharing and by introducing some degree of energy-weighting.

本研究着重于两种X射线相衬成像（XPCI）技术的实现：具有微焦点多色X射线源和Timepix3光子的自由空间传播（FSP）和单掩模边缘照明（SM-EI）带有CdTe传感器的计数检测器。该探测器提供高空间分辨率，高探测效率，并且能够针对每个X射线光子同时记录有关阈值时间（ToT）和到达时间（ToA）的信息。所有这些功能在提高XPCI图像质量（尤其是通过光谱分析）方面起着关键作用，因为可以测量每个入射X射线光子的能量。给出了在软X射线成像的典型光谱内不同能量仓的相衬对比度和对比度噪声比（CNR）的测量结果。