362 / 2019-02-28 00:47:01

The high spectral resolution single shot spectrometer for absorption spectrum measurements

XFEL Absorption spectrum, single shot

全体主题 > Science and Technology based on XFEL

For XFEL, one baseline X-ray creation process is called Self-Amplification of Spontaneous Emission (SASE). The stochastic nature of SASE-XFEL radiation gives rise to shot to shot fluctuations of beam properties, including its spectral content. The precise knowledge of incident X-ray spectra on a shot by shot basis is crucial for normalization of absorption spectra. The high spectral resolution spectrometer (SSP) is an on-line monitor for single-shot spectral diagnostics. The spectrometer is based on the ultrathin bent crystals. A defocusing geometry using convex crystals is used to gain high resolution. Four different cuts of silicon crystals are used to measure the energy range from 3keV to 25keV which is covered the whole photon energy range of European XFEL. The actual design is compatible with the use of a grating. This can be implemented in the future and will be especially useful for the low energy range. The SSP is developed by the collaboration of CAEP and European XFEL and will be used to inspect and measure the incident X-ray spectra of HED instrument. Especially for the research by absorption spectrum measurements.