The Gas-phase end station (GPES), shown in the photo below, has been designed for photoelectron-photoion coincidence (PEPICO) experiments of gas phase targets and samples with high vapour pressure. The main instruments are a Scienta R4000 electron spectrometer and a momentum imaging multi-hit-capable ion Time-of-Flight (TOF) spectrometer. They are equipped with fast position-sensitive detectors that are particularly designed for coincidence measurements. The electron and ion spectrometers can also be used independently for high-resolution electron and ion spectroscopy or to collect electron and ion yields as a function of photon energy. The coincidence set-up is controlled by tailor-made software.

The GPES has been designed to accommodate a variety of sample preparation systems, provided by the FinEstBeAMS consortium or by external users. Initially, gas inlet systems and solid target vaporisation set-ups will be available.

A second, exchangeable chamber can be mounted downstream of the electron-ion coincidence set-up. It can host various user instruments. It can be moved to the focal plane of the beamline for the best experimental conditions, when a connection pipe between the GPES and the beamline is removed.













Gas-phase endstation at FinEstBeAMS.