BESSY II
LowDosePES - PM4 beamline

Soft X-ray dipole variable polarisation with PGM and MHz Chopper Beamline for LowDosePES

This soft x-ray bending magnet beamline is equipped with a Plane Grating Monochromator operated in collimated light (collimated PGM) and with a MHz Chopper System to create single bunch on demand for the ArTOF Low Dose PES end-station.

 

Low Dose Photoelectron Spectroscopy Station at PM4

The LowDose PES end-station is permanently installed at the PM4 dipole beamline. 

It is equipped with a SES100 hemispherical analyzer, as well as with a novel angle-resolved time-of-flight (ArTOF) spectrometer. 

Distinctive features of the latter are an extremely high transmission and the possibility to collect electrons over a very broad angular range in parallel. 

Thanks to the high transmission of the ArTOF, up to 1000 times faster acquisition times and equally reduced dose rates can be achieved with respect to the more conventional hemispherical analyzers, thus making possible PES investigations of materials that usually suffer from radiation damage. 

When further considering its full cone detection capabilities, the ArTOF turns out to be particularly suitable to track changes in the sample electronic structure as a function of parameters such as gas exposure, temperature or delay after excitation from an optical pump. 

As the ArTOF calls for a pulsed source with repetition rate of few MHz maximum, a fast mechanical chopper is installed at the intermediate focus of the beamline enabling permanent access to 1.25 MHz - spaced X-ray bunches, not only with the single-bunch filling pattern of the storage ring, but also during the more common hybrid operation mode.

The end-station has access to a synchronized ultra-fast (300 fs) high-average power (30 W) high- repetition rate (up to 2MHz) infrared (1030 nm) laser (and its second to fourth harmonics) for time-resolved laser-pump/ x-ray-probe photoemission measurements.

Beamline Energy Range
20 - 2000 [eV]
Max Flux On Sample
1 * 1010 [ph/s]
contacts
Dr. Ruslan Ovsyannikov
Dr. Erika Giangrisostomi
Techniques
Absorption
  • NEXAFS
Photoelectron emission
  • Angular Resolved PES
  • Time-resolved studies
  • UPS
  • XPS
Disciplines
Chemistry
  • Catalysis
  • Electrochemistry
  • Green Chemistry
  • Physical Chemistry
Energy
  • Sustainable energy systems
Engineering & Technology
  • Nanotechnology & production processes
Life Sciences & Biotech
  • Biophysics
Material Sciences
  • Knowledge based multifunctional materials
  • Other - Material Sciences
Physics
  • Dynamics
  • Hard condensed matter - electronic properties
  • Hard condensed matter - structures
  • Nanophysics & physics of confined matter
  • Soft condensed matter physics
  • Surfaces, interfaces and thin films
control/Data analysis
Control Software Type
  • tbc
Data Output Type
  • tbc
Data Output Format
  • tbc