Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom.
Phys Rev Lett. 2015 Mar 13;114(10):103901. doi: 10.1103/PhysRevLett.114.103901. Epub 2015 Mar 11.
X-ray dark-field imaging can provide inaccessible and complementary information compared to conventional absorption contrast imaging. However, extraction of the dark-field signal is difficult, and sophisticated optics are often required. In this Letter, we report a novel approach to generate high-quality dark-field images using a simple membrane. The dark-field image is extracted from the maximum correlation coefficient by applying a cross-correlation algorithm to a stack of speckle images collected by scanning a membrane in a transverse direction to the incident x-ray beam. The new method can also provide directional dark-field information, which is extremely useful for the study of strongly ordered systems. The potential of the proposed technique for nondestructive x-ray imaging is demonstrated by imaging representative samples.
X 射线暗场成像是一种与传统吸收对比度成像相比可以提供更难获取但互补的信息的技术。然而，暗场信号的提取很困难，通常需要复杂的光学元件。在这封信件中，我们报告了一种使用简单的膜片生成高质量暗场图像的新方法。通过对在与入射 X 射线束横向扫描膜片时采集的散斑图像进行堆栈，应用互相关算法，从最大相关系数中提取暗场图像。这种新方法还可以提供具有方向的暗场信息，这对于研究强有序系统非常有用。通过对代表性样本成像，展示了所提出技术在无损 X 射线成像中的潜力。
