We developed a single-shot X-ray spectrometer for wide-range high-resolution measurements\nof Self-Amplified Spontaneous Emission (SASE) X-ray Free Electron Laser (XFEL) pulses. The\nspectrometer consists of a multi-layer elliptical mirror for producing a large divergence of 22 mrad\naround 9070 eV and a silicon (553) analyzer crystal. We achieved a wide energy range of 55 eV with a\nfine spectral resolution of 80 meV, which enabled the observation of a whole SASE-XFEL spectrum\nwith fully-resolved spike structures. We found that a SASE-XFEL pulse has around 60 longitudinal\nmodes with a pulse duration of 7.7 �± 1.1 fs.
Loading....