BElChem-PGM

Berlin Joint Lab for Electrochemical Interfaces @U49-2 PGM

The BElChem-PGM beamline covers the soft X-ray energy range from approximately 90 eV to 2000 eV with a plane grating monochromator. Its source is a planar undulator with a period length of 49.4 mm (U49-2) and minimum gap of 16 mm. The optical elements and layout of the beamline have been optimized to deliver a high photon flux over a broad energy range, in particular at energies above 800 eV, with moderate spectral resolution. This helps to facilitate in-situ and operando experiments that are conducted at elevated gas pressures or in liquids.

Anwendungsbeispiele:
  • X-ray photoelectron spectroscopy (XPS) under high vacuum (p=10^(-8) mbar) and near ambient pressure conditions (maximum 20 mbar, typically 1 mbar)
  • X-ray aborption spectroscopy (XAS) at pressure up to 20 mbar with NAP-HE-XPS endstation
  • log-in methodology applying the beamline chopper to modulate the incoming X-ray induced signal
Optical layout (top and side views) of the future BElChem plane grating monochromator (PGM) beamline. The concept of the beamline is based on a SX700-type monochromator working in collimated light served by a planar undulator U49-2 providing photons within the soft X-ray range.

Optical layout (top and side views) of the future BElChem plane grating monochromator (PGM) beamline. The concept of the beamline is based on a SX700-type monochromator working in collimated light served by a planar undulator U49-2 providing photons within the soft X-ray range.


Station data
Temperature range room temperature up to 1000 K
Pressure range Maximum pressure: 20 mbar
Minimum pressure: 10-8 mbar
Typical pressure: 1 mbar

For more details contact the instrument scientist.
Weitere Details BElChem-PGM station
Beamline data
Segment H05
Location (Pillar) 6.2
Source U49-2 (planar undulator)
Monochromator PGM
Energy range 90 - 2000 eV
Energy resolution 70meV at 400eV photon energy
Flux 4.00 1013 mbar photons/s@300mA
Polarisation horizontal
Divergence horizontal 10 mrad
Divergence vertical 10 mrad
Focus size (hor. x vert.) 100 µm X 20 µm (expected)
User endstation
Distance Focus/last valve 964 mm
Height Focus/floor level 1400 mm
Beam availability 24h/d, operation in TRIBS mode possible
Phone +49 30 8062 14842
beamline specials mechancial choppper
differentially pumped interface
Expected performance (photon flux and spectral resolution, respectively) of the future BElChem-PGM beamline as obtained by ray tracing

Expected performance (photon flux and spectral resolution, respectively) of the future BElChem-PGM beamline as obtained by ray tracing


For more details and current status please contact instrument scientist(s) listed on the right.

The Berlin Joint Lab for Electrochemical Interfaces (BElChem) is located at the BESSY II synchrotron in Berlin, Germany, and co-run by the Fritz-Haber-Institut, the Max-Planck-Institut of Chemical Energy Conversion and the Helmholtz-Zentrum Berlin. BElChem focuses on providing a molecular-level description of (photo)electrochemical interfaces that are of high relevance for solar fuel production and renewable energy storage.

The BElChem facility consists of two beamlines with two endstations in two separate hutches and an additional sample preparation/chemical lab. BElChem-PGM (plane grating monochromator) covers the soft X-ray energy range, whereas BElChem-DCM (a dipole magnet sourced beamline) with a double crystal monochromator (DCM) covers the tender X-ray energy range.

Please find more details on BElChem in 

David E. Starr, Michael Hävecker, Axel Knop-Gericke, Marco Favaro, Simone Vadilonga, Marcel Mertin, Gerd Reichardt, Jan-Simon Schmidt, Frank Siewert, Robert Schulz, Jens Viefhaus, Christian Jung & Roel van de Krol (2022) The Berlin Joint Lab for Electrochemical Interfaces, BElChem: A Facility for In-situ and Operando NAP-XPS and NAP-HAXPES Studies of Electrochemical Interfaces at BESSY II, Synchrotron Radiation News, 35:3, 54-60, DOI: 10.1080/08940886.2022.2082209