论文标题
X射线游离电子激光器的单发X射线吸收光谱
Single-shot X-ray Absorption Spectroscopy at X-ray Free Electron Lasers
论文作者
论文摘要
X射线吸收光谱（XAS）是一种广泛使用的X射线诊断方法。虽然Synchrotrons具有大量的XAS用户社区，但其在X射线免费电子激光器（XFEL）设施上的使用却相当有限。乍一看，XFEL源的相对狭窄的带宽和高度波动的光谱结构似乎可以防止高质量的XAS测量值，而不会在许多镜头上积聚。在这里，我们首次演示了XFEL上单次XAS光谱的集合，而错误条仅为数十EV。我们通过连接几十个单发测量值来展示如何将该技术扩展到较宽的光谱范围朝向扩展的X射线吸收精细结构（EXAFS）测量。这些结果对未来飞秒时间的XAS研究开放了无可争议的观点，尤其是对于可以以低重复速率启动的瞬态过程。
X-ray Absorption Spectroscopy (XAS) is a widely used X-ray diagnostic method. While synchrotrons have large communities of XAS users, its use on X-Ray Free Electron Lasers (XFEL) facilities has been rather limited. At a first glance, the relatively narrow bandwidth and the highly fluctuating spectral structure of XFEL sources seem to prevent high-quality XAS measurements without accumulating over many shots. Here, we demonstrate for the first time the collection of single-shot XAS spectra on an XFEL, with error bars of only a few percent, over tens of eV. We show how this technique can be extended over wider spectral ranges towards Extended X-ray Absorption Fine Structure (EXAFS) measurements, by concatenating a few tens of single-shot measurements. Such results open indisputable perspectives for future femtosecond time resolved XAS studies, especially for transient processes that can be initiated at low repetition rate.
