Reaction microscope endstation at FLASH2

A reaction microscope dedicated to multi‐particle coincidence spectroscopy on gas‐phase samples is installed at beamline FL26 of the free‐electron laser FLASH2 in Hamburg. The main goals of the instrument are to follow the dynamics of atoms, molecules and small clusters on their natural time‐scale and to study non‐linear light–matter interaction with such systems. To this end, the reaction microscope is combined with an in‐line extreme‐ultraviolet (XUV) split‐delay and focusing optics, which allows time‐resolved XUV‐XUV pump–probe spectroscopy to be performed. The instrumentation and commissioning results of the reaction microscope endstation at FLASH2 are reported.