Operation of hard X-ray single-shot spectrometer for MHz spectral measurement at European XFEL

The European X-ray Free Electron Laser (EuXFEL) is a user facility delivering soft and hard X-ray FEL radiation. It provides 2700 pulses at a 10 Hz with femtosecond up to 4.5 MHz pulse repetition rate and X-ray with high brilliance and intensities in the photon energy range 0.5 keV to 25 keV. The FEL radiation which is created by the Self Amplified Spontaneous Emission (SASE) process, whose stochastic nature gives rise to shot-to-shot fluctuations of the pulse energy and spectrum. In order to cover these variations, the HIgh REsolution hard X-ray single-shot (HIREX) spectrometer has been installed in the Hard X-ray beamlines SASE1 and SASE2. The HIREX spectrometer is an online device, based on a bent diamond and Silicon crystal as a dispersive element and a MHz-repetition rate GOTTHARD strip detector. The two spectrometers have upgraded with 4.5 MHz GOTTHARD-II detector. Thus, the spectrometers have new capability of measuring the spectral data in the MHz repetiton rate.