XANES@KMC-2

XANES@KMC-2

The instrument is located at the KMC-2 beamline, which provides linearly polarized light in the energy range of 4 keV – 15 keV for X-ray absorption spectroscopies (EXAFS, XANES), fluorescence, diffractometry and reflectometry. Beam intensity is stabilized by MOSTAB electronics with an accuracy of 0.3 %. KMC-2 XANES is a dedicated instrument for X-ray Absorption Spectroscopy measurements at-air. The experimental setup allows for a parallel monitoring of the transmitted through the sample X-ray beam intensity as well as for fluorescence yield measurements.

Anwendungsbeispiele:
  • investigate the short-range environment around selected atomic species in condensed matter
  • study structural properties in various materials like: liquids, molecular solutions, liquid crystals; single- and poly-crystalline materials; amorphous and highly disordered solids; molecules and macromolecules containing metallic atoms or partially substituted with heavy atoms


Methods

EXAFS, NEXAFS, XRF, XRF Mapping

Remote access

not possible

Instrument data
Phone (~49 30 8062-) 14623
Source D9.2 (Dipole)
Beam availability 24h/d
Monochromator Si 111, Ge-graded
Energy range (at experiment) 4 - 15 keV
Energy resolution 1/4000
Flux 10710
Polarisation linear horizontal
Focus size (hor. x vert.)
  • 250 μm x 600 μm
  • 4.8 μm x 4.8 μm with capillary optics
Temperature range 293 K
Pressure range For details contact the Instrument Scientist
Detector Bruker X-Flash 6|60, 3 ionization chambers, Si-PIN photodiodes, scintillation counter
Manipulators Huber goniometer
Sample holder compatibility
  • Maximum sample size: unlimited
  • For details contact the Instrument Scientist
Additional equipment
  • Microfocusing: > 5 μm
  • Micro-EXAFS, Micro-fluorescence: limited / no mapping
  • Beam intensity stabilization: MOSTAB electronics (accuracy 0.3%)
  • Control system: PC-based BESSY monochromator control system EMP/2
  • Data-acquisition computer: PC, measurement bus-extension, OS/2-operating system
  • Data acquisition software: Windows-NT, RADICON RDPW software
Additional information Further details: beamline KMC-2


Instrument application

X-ray Absorption Spectroscopy (XAS) is a powerful structural technique to investigate the short-range environment around selected atomic species in condensed matter. While scanning the x-ray energy impinging onto the sample, a core level photoelectron is generated. This is scattered by the surroundings matter producing interference effects visible in the absorption cross-section and usually referred to as x-ray absorption fine structure (XAFS). The process itself is general and therefore fundamental to study structural properties in materials like:

  • liquids, molecular solutions, liquid crystals
  • single- and poly-crystalline materials
  • amorphous and highly disordered solids
  • molecules and macromolecules containing metallic atoms or partially substituted with heavy atoms

The energy range 4.0 keV < E < 15 keV is sufficient for K-edge studies of elements in the range 21 < Z < 36 and L-edge studies of elements in the range 49 < Z < 83. The sample thicknesses for experiments are in the µm range for transmission experiments. However, thin film and/or dilute systems studies are still possible in fluorescence mode.