U41-PEAXIS Beamline - Combined RIXS and XPS

U41-PEAXIS beamline is one of the highest flux beamlines at BESSY II. It provides highly focused soft X-rays, thanks to the ellipsoidal refocusing mirror. The beamline is connected to a fixed endstation PEAXIS that is dedicated to studies of angle-resolved RIXS (Resonant Inelastic X-ray Scattering) and PES (PhotoElectron Spectroscopy) on solids and liquids that are sealed in a fluid micro-cell.

Beamline layout

Photon flux at the exit slit. The flux at the sample position is roughly half of it.

Beamline resolution @ 401 eV

Beamline resolution @ 867 eV

Focal spot @ 400 eV and slit 20 µm

PEAXIS Station - Combined RIXS and XPS

The station PEAXIS (PhotoElectron Analysis and X-ray Inelastic Spectroscopy) is a fixed experimental station installed at the U41-PEAXIS beamline, in user operation since October 2018. It is dedicated to studies of angle-resolved RIXS (Resonant Inelastic X-ray Scattering) and PES (PhotoElectron Spectroscopy) on solids and liquid cells. As shown in the Schematic figure below, the station is equipped with an electron energy analyzer (violet) and a RIXS spectrometer (blue). Various sample manipulators (red) can be installed in the sample chamber (green) according to different sample environments. The RIXS spectrometer includes a grating chamber (dark blue), a five-meter RIXS arm (light blue) and a CCD detector (orange). The RIXS arm is continuously rotatable on a supporting rail in a range of 106.5 degrees.

Schematic of the PEAXIS station

Photo of the PEAXIS station

RIXS spectra of liquid acetone vibrations detected at the excitation energy of 531 eV and various θ angles. The intense peaks at the channel 1000 come from the elastic scattering, and the rest, equally-spaced peaks represent the vibrational excited final states in the electronic ground state. The RIXS resolution (combined with the beamline) at 531 eV is about 60 meV.