PLEIADES is an ultra high resolution soft X-ray beamline (ultimate resolving power of about 100000 at 50 eV) covering the energy range from 9 eV to 1 keV. PLEIADES is dedicated to spectroscopy based atomic and molecular physics studies of dilute samples (atoms, molecules, ions, cluster, nanoparticles). All horizontal,vertical and tilted linear polarizations, as well as circular and elliptical polarizations, are available starting from 55 eV thanks to a permanent magnet (80 mm period) Apple II type of undulator. Linear horizontal and vertical polarized beams are available as low as 10 eV from a 2nd (256 mm period) electromagnetic undulator. In the beamline design, particular care has been taken in order to obtain a spectrally pure soft X-ray beam : thanks to an appropriate combination of quasi-periodic design for the low-energy undulator and the use of a varied groove depth (VGD) for the plane grating, higher orders are very partly rejected. A high resolution electron spectrometer, an energy and angle Auger electron - ion coincidence setup (EPICEA), as well as a dedicated station (MAIA) for positive and negative ion photoionization studies (ECRsource) are permanently installed on the beamline. The beamline has three optical branches with different focusing properties of the beam. Two of them (branch N°2 and N°3) are offering the external users the possibility of installing their own setups (see table below for spot sizes and beam divergences on sample).

Beamline Energy Resolution
1 * 10-5 [eV] @ 50 [eV]
4 * 10-5 [eV] @ 550 [eV]
Beamline Resolving Power
1 * 105 [deltaE/E] @ 50 [eV]
2.5 * 105 [deltaE/E] @ 550 [eV]
Beamline Energy Range
10 - 1000 [eV]
Max Flux On Sample
3.5 * 1013 [ph/s] @ 98 [eV]
Spot Size On Sample Hor
15 - 2000 [um]
Spot Size On Sample Vert
25 - 3000 [um]
Emission or Reflection
  • Polarimetry
Photoelectron emission
  • Angular Resolved PES
  • Photoelectron diffraction
  • UPS
  • XPS
  • Atoms, molecules, clusters and gas-phase chemistry
  • Catalysis
  • Electrochemistry
  • Femtochemistry, solid- and liquid-state chemistry
  • Physical Chemistry
Life Sciences & Biotech
  • Pharmaceutics (drug screening)
  • Atomic & molecular physics
control/Data analysis
Control Software Type
  • IgorPro, GlobalScreen, Java Tools
Data Output Type
  • detector images, spectra, all beamline parameters, sample pressure, relative photon flux
Data Output Format
  • IgorPro waves or IgorPro packed experiment
Softwares For Data Analysis
  • IgorPro by WaveMetrics Inc.
in partnership with