Institute for Nanometer Optics and Technology, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, Berlin 12489, Germany.
J Synchrotron Radiat. 2013 Jul;20(Pt 4):522-30. doi: 10.1107/S0909049513008613. Epub 2013 May 1.
Aiming at advancing storage-ring-based ultrafast X-ray science, over the past few years many upgrades have been undertaken to continue improving beamline performance and photon flux at the Femtoslicing facility at BESSY II. In this article the particular design upgrade of one of the key optical components, the zone-plate monochromator (ZPM) beamline, is reported. The beamline is devoted to optical pump/soft X-ray probe applications with 100 fs (FWHM) X-ray pulses in the soft X-ray range at variable polarization. A novel approach consisting of an array of nine off-axis reflection zone plates is used for a gapless coverage of the spectral range between 410 and 1333 eV at a designed resolution of E/ΔE = 500 and a pulse elongation of only 30 fs. With the upgrade of the ZPM the following was achieved: a smaller focus, an improved spectral resolution and bandwidth as well as excellent long-term stability. The beamline will enable a new class of ultrafast applications with variable optical excitation wavelength and variable polarization.
针对推进基于储存环的超快 X 射线科学，在过去几年中，BESSY II 的 Femtoslicing 设施已经进行了多次升级，以继续提高谱线性能和光子通量。本文报告了其中一个关键光学组件——波带板单色仪（ZPM）谱线的特殊设计升级。该谱线专门用于光学泵浦/软 X 射线探测应用，在软 X 射线范围内提供 100 fs（FWHM）的 X 射线脉冲，具有可变偏振。该谱线采用了一种由九个离轴反射波带板组成的阵列，用于在设计分辨率为 E/ΔE=500 和脉冲展宽仅为 30 fs 的情况下，对 410 至 1333 eV 之间的光谱范围进行无间隙覆盖。通过对 ZPM 的升级，实现了更小的焦点、更高的光谱分辨率和带宽以及出色的长期稳定性。该谱线将能够实现具有可变光学激发波长和可变偏振的新型超快应用。
