Pascarelli S, Boscherini F, D'Acapito F, Hrdy J, Meneghini C, Mobilio S
J Synchrotron Radiat. 1996 Jul 1;3(Pt 4):147-55. doi: 10.1107/S0909049596004992.
The performance of a dynamical sagittal-focusing monochromator for hard X-rays is described. It consists of a flat first crystal and a diamond-shaped ribbed second crystal which is clamped by its central rib and dynamically bent by applying a force on its two apices. The system has proved to perform very well on the GILDA beamline at the ESRF. The horizontal acceptance varies with energy and with focusing geometry as predicted theoretically; the total available horizontal fan of radiation (3.6 mrad) is in fact collected in the 1:3 geometry. The system is routinely run in a dynamical focusing mode for XAFS spectroscopy in the energy range 5-30 keV with Si(311) crystals, with a constant spot size FWHM ~1 mm on the sample and without degradation of energy resolution or reproducibility. Using simple geometrical considerations we calculate the variations of the horizontal profile of the reflected beam during rocking-curve scans in different focusing geometries and find them in agreement with observed ones. Not only is this is a practical aid in alignment but it illustrates the X-ray optics of sagittal focusing in an elegant way.
描述了一种用于硬X射线的动态矢状聚焦单色仪的性能。它由一块平坦的第一晶体和一个菱形带肋的第二晶体组成，第二晶体通过其中心肋夹紧，并通过在其两个顶点施加力而动态弯曲。该系统已证明在欧洲同步辐射装置（ESRF）的吉尔达光束线上运行良好。水平接受度随能量和聚焦几何形状而变化，正如理论预测的那样；实际上，在1:3几何形状中收集了总的可用水平辐射扇形（3.6毫弧度）。该系统通常在动态聚焦模式下运行，使用Si(311)晶体进行能量范围为5 - 30 keV的XAFS光谱分析，在样品上的光斑尺寸半高宽（FWHM）恒定约为1毫米，且能量分辨率或重现性没有下降。通过简单的几何考虑，我们计算了在不同聚焦几何形状下摇摆曲线扫描期间反射光束水平轮廓的变化，并发现它们与观察到的结果一致。这不仅在对准方面是一种实用的辅助手段，而且以一种简洁的方式说明了矢状聚焦的X射线光学原理。
