To discuss the scientific opportunities offered by the availability of a high-resolution hemispherical electron spectrometer at the SQS instrument of the European XFEL a two-day workshop is organized at the European XFEL in Schenefeld on July 1-2, 2024.
This new electron spectrometer is provided to SQS as a user contribution from the French Centre National de la Recherche Scientifique (CNRS) and design, construction and commissioning of the spectrometer was coordinated by J. Bozek (SOLEIL) and M. Simon (Sorbonne U). After commissioning at the instrument this device will be made available to all users of SQS. The spectrometer will allow high-energy-resolution electron spectra to be recorded with a variable resolution as small as several millielectron volts. In addition, the large acceptance angle (±30°) will assure high collection efficiency and angular resolution over 60° range. Additionally, electrons from an 8-mm long interaction volume can be collected, preserving the position of their emission along the FEL beam, allowing for creative pump-probe configurations or intensity variations (as the beam size varies) to be observed. We envision that the spectrometer will enable a deeper and more detailed analysis of many processes providing a particular advantage for time-resolved pump-probe (X-ray – optical laser or X-ray – X-ray) studies as well as for investigations of non-linear phenomena in the X-ray regime. The initial objective is fundamental AMO research using atomic and molecular beams, but other applications, e.g. on liquid-beam targets or cluster and nanoparticle beams can also be discussed.
