A mobile UHV-system designed for femtosecond time, energy and spin resolved photoelectron spectroscopy

We report on the design and tests of a completely mobile photoemission end station for femtosecond time, energy and spin resolved magnetodynamics experiments. The setup is designed for the use at free-electron laser (FEL) x-ray beamlines as well as at synchrotron facilities. In situ sample preparation in an adjacent UHV chamber is performed. The assembly can be altered to obtain energy resolved measurements with the help of a hemispherical electron energy analyzer or to obtain energy integrated measurements by inserting an electron transfer lens system. The magnetic information is obtained by spin analysis with a 50 kV Mott detector. The setup is tested in house with an electron gun, at the Swiss Light Source (SLS) and has been used at the FEL at FLASH in Hamburg. Results show the practicability of the system and exemplarily the kinetic energy dependent polarization of the low energy secondary electrons emitted from a 15 ML iron film on W(110) is presented.