Variable polarization undulator beamline with plane-grating monochromator feeding the Coincidence ESCA Experiment and the nano Cluster Trap
The COincidence Electron Spectroscopy for Chemical Analysis station is at a plane grating monochromator beamline with a UE-52 undulator. The beamline offers photons in linear polarisation from 110-1900 eV and in elliptical polarisation from 110-1390 eV and can be switched in “one-click” between mutli-bunch and the quasi single bunch PPRE mode (PPRE: pulse-picking by resonant excitation).
The CoESCA station is equipped with two Angle-Resolved Time-Of-Flight spectrometers, one ArTOF 10k prototype with an angular acceptance of 30° and one ArTOF2-EW with a wider angular acceptance of 56°. Thus both spectrometers measure the 3D angular resolved electron distributions. Further they can be operated either independently or in coincidence mode. The data is saved shot-to-shot for both spectrometers and hence the time evolution of the data can be investigated in post-processing on slow time scales from minutes to hours. The ArTOFs’ high information rate makes studies of radiation sensitive samples at very low photon flux feasible even in a reasonable acquisition time.
The main experimental chamber features a 5-axis sample manipulator, with the possibility to cool or heat the sample (T = 30-1200 K), put up a bias voltage and measure the sample current for basic absorption measurements. The end-station is equipped with sample loading, storing and preparation facilities. The preparation chamber is equipped with a sample heating stage (up to 800°C), a quartz balance, a mass spectrometer and free ports for mounting user provided equipment (e.g. evaporators). Furthermore, the transfer system is ready for additional, users-provided preparation chambers.
CoESCA end-station layout