Build your own Micro-XRD-XRF System

We present an in-house built micro-focus X-ray setup for diffraction and fluorescence measurements. The complete system was assembled, commissioned and tested in the course of laboratory internships and bachelor education, providing first-hand experience to students in the design, construction of an experimental analytical device and its application to a scientific problem.

At the heart of the machine is a Ag micro-focus X-ray tube with a multi-layer optic that provides a focal spot of 50 µm at a distance of 200 mm with a photon flux of 10⁶ photons/sec at 22 keV. XRD patterns are collected on a mar345 image plate detector. XRF spectra are recorded by a Ketek Si-drift detector with 30 mm² active area and a digital signal processing unit. Beam intensity is monitored by a Si-PIN diode. The sample is mounted on a Huber XYZ stage with one vertical rotation and a second long translational stage perpendicular to the beam. An optical microscope allows for observation of the sample. The whole system is operated using TANGO (www.tango-controls.org) and SARDANA (www.sardana-controls.org).

The performance is presented with three examples: i) quantitative measurements of reference material ii) destruction-free analysis of an unprepared grain of Mukundpura CM2-Chondrit providing spatially resolved semi-quantitative mineralogical and chemical information; iii) in-situ high-pressure measurements of the unit-cell volume of a spinel by XRD up to 15 GPa using a diamond anvil cell.

Acknowledgements: Thanks to: L. Hecht MfN Berlin, E. Bonato, DLR Berlin, for providing the meteorite sample; S. Niese, AXO Dresden, for technical support.