论文标题
Sase3软X射线光束线在欧洲XFEL上的单色操作
Monochromatic operation of the SASE3 soft X-ray beamline at European XFEL
论文作者
论文摘要
欧洲XFEL处的SASE3软X射线光束线已设计和构建，以在光子能量范围250 eV -3000 eV的光子能量范围内提供粉红色或单色光束。在这里，我们专注于Sase3梁线的单色操作，并报告Sase3光栅单色器的设计和性能。 FEL源产生高度连贯性的短飞秒脉冲的独特能力通过控制光子能量和时间分辨率的需求来挑战单色仪设计。接近转换有限脉冲的运输的目的对光学质量（尤其是在光栅上）的需求非常高。与最佳设计性能相比，讨论了Sase3单色器的当前实现。目前，单色仪具有两个光栅：低分辨率的光栅已针对时间分辨的实验进行了优化，并允许在2000-5000大约2000-5000的中等分辨能力，以及脉搏伸展很少至几英尺至几英里的fevtoSconds rms，以及高分辨率的螺旋式启动的高分辨率触发功能，即可达到10000的较大脉冲伸展的脉冲功率。
The SASE3 soft X-ray beamline at the European XFEL has been designed and built to provide experiments with pink or monochromatic beam in the photon energy range 250 eV - 3000 eV. Here, we focus on the monochromatic operation of the SASE3 beamline and report on design and performance of the SASE3 grating monochromator. The unique capability of an FEL source to produce short femtosecond pulses of high degree of coherence challenges the monochromator design by a demand to control both photon energy and temporal resolution. The aim to transport close to transform-limited pulses poses very high demands on the optics quality, in particular on the grating. The current realization of the SASE3 monochromator is discussed in comparison with optimal design performance. Presently, the monochromator operates with two gratings: the low-resolution grating is optimized for time-resolved experiments and allows for moderate resolving power of about 2000 - 5000 along with pulse stretching of few to few tens of femtoseconds RMS, and the high-resolution grating reaches resolving power of 10000 at a cost of larger pulse stretching.
