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X-ray absorption spectroscopy
Australian Synchrotron beamlines

X-ray absorption spectroscopy

X-ray absorption spectroscopy (XAS) is a versatile tool for chemistry, biology, and materials science. By probing how x rays are absorbed from core electrons of atoms in a sample, the technique can reveal the local structure around selected atoms.

X-ray absorption spectroscopy (XAS) is a versatile tool for chemistry, biology, and materials science. By probing how x rays are absorbed from core electrons of atoms in a sample, the technique can reveal the local structure around selected atoms.

Techniques available

Hutch B:

The first experimental hutch is optimised for transmission and fluorescence XAS on "standard samples" in standard sample holders. This hutch supports the use of three ionization chambers, a multi-element solid state Ge fluorescence detector, a PIPS detector, soller slits and filters, a fast beam shutter, a 10K cryostat, and a room temperature sample stage. In order to use this experimental hutch, samples/environments must fit within our cryostat or our room temperature sample stage. There is also a harmonic rejection mirror sitting on the optical table for use at energies below the Fe K-edge.

Hutch C:

The second experimental hutch is designed to allow "non-standard samples" in non-standard sample holders / user supplied sample environments. The hutch is currently available for transmission type experiments, including the use of our in-situ heater. If you seek to use this hutch you must contact us well in advance of any proposal deadline to establish technical feasibility. The optical table currently has three ionization chambers, a set of slits, and motorised stages for user-supplied equipment. Note that there is no harmonic rejection mirror available in this hutch and as such only experiments at the Fe K-edge and above are possible (> 7 keV).

  • Standard samples: e.g. powders, films, or liquids that fit in our standard sample holders.
  • Non-standard samples: e.g. large, fragile, radioactive, or bio-hazards that do not fit in our standard sample holders, and would often be mounted in user-supplied sample environments.

Photon delivery system

 Source

1.9T Wiggler
 Available Energy range5 - 31 keV
 Optimal Energy range

Mode 1: 5 - 9 keV using Si(111)

Mode 2: 8.5 - 18.5 keV using Si(111)

Mode 3: 15 - 31 keV using Si(311)

 Resolution deltaE/ECrystal dependent:
~ 1.5x10-4 using Si(111)
~ 0.4x10-4 using Si(311)
 Nominal beam size at sample

~ 0.25 by 0.25 mm fully focussed

 Photon flux at sample 1010 to 1012 ph/s using Si(111)
109 to 1011 ph/s using Si(311)
 Harmonic content at 5-18 keV  < 10-5

Detectors and Ancillaries

The beamline consists of two experimental stations: Hutch B and Hutch C.

In Hutch B standard experiments are run. These are experiments requiring little or no modification from one user group to the next in terms of hardware setup. That limits the type of experiments to samples prepared in our standard sample holders to be measured either at ambient temperature and pressure or in our cryostat in transmission or fluorescence mode.

In Hutch C non-standard experiments may be run. This type of experiments include users having their own apparatus, e.g. sample environments or detectors. Note that the lowest energy feasible in Hutch C is the Fe K edge at 7 keV.  

 Hutch B (5 to 31 keV)

Hutch C (7 to 31 keV)
Optical table 2.4 by 1.2 mOptical table 2.4 by 1.2 m
100 element Ge fluoro detector

36 element Ge fluoro detector

 3 ion chambers3 ion chambers
Cryostat and room temperature holder

In-situ heating stage to ~1000C

Harmonic rejection mirrorVarious stages
Fast shutter 

In-situ heater (XAS)

The XAS beamline will be offering an in-situ heater from the second cycle of 2013 in the second experimental hutch (Hutch C). Please contact Bernt ( bernt.j@synchrotron.org.au ) for further information. See also B. Johannessen, ZS Hussain, DR East, MA Gibson, An in-situ heater for the XAS beamline (12-ID) in Australia, J. Phys.: Conf. Ser. 430 (2013) 012119.

in-situ heater xas

 

Beamtime