Diamond Light Source
Beamline I15-1 - X-ray Pair Distribution Function (XPDF)


XPDF (I15-1) is the dedicated X-ray Pair Distribution Function beamline. XPDF is applicable to a diverse range of disciplines such as materials chemistry, solid-state physics, earth sciences and pharmaceuticals.

Researchers are able to study the local structure of crystalline, semi-crystalline and amorphous solids and liquids with a speed and robustness which has not been possible at Diamond before. The beamline optics and endstation have been optimised to give the high X-ray energy, high flux and low background signal which are necessary for quality PDF data.

XPDF typically operates with two large area detectors, one placed close to the sample to the provide the large Q range required for quality PDF data (Qmax up to 40 Å–1 at 76.7 keV) and one mounted further from the sample for simultaneous higher-resolution Bragg data.


Beamline Energy Resolution
5 * 10-4 [meV] @ 20 [eV]
Beamline Resolving Power
2 * 103 [deltaE/E] @ 20 [eV]
Beamline Energy Range
20 - 80 [eV]
Spot Size On Sample Hor
5 - 1000 [um]
Spot Size On Sample Vert
5 - 1000 [um]
Christine Beavers
  • Powder diffraction
  • Elastic scattering
control/Data analysis
Control Software Type
  • GDA
Data Output Type
  • image
Data Output Format
  • ascii, tiff, jpeg, nexus
Softwares For Data Analysis
  • DAWN/in-house, TOPAS/commercial