High-Speed PIXE: Fast and laterally resolved elemental analysis over wide areas

A new PIXE (particle-induced X-ray emission) beamline equipped with a full-field energy-dispersive X-ray camera [1,2] has been recently put into operation at HZDR. The so-called High-Speed PIXE is a combination of a 264 x 264 pixel-detector with polycapillary optics guiding the proton-induced X-ray fluorescence radiation towards a pnCCD-chip with an energy resolution of 156 eV (@Mn-Kα). It allows a fast detection of elements over a field of 12 x 12 mm² simultaneously with a lateral resolution better than 100 µm, even at the trace level (<0.1 at.%). A large vacuum sample chamber containing a high-precision sample manipulator (Figure 1) enables a high throughput of even large and heavy samples.
The new set-up is mainly developed for the investigation of geological samples for resource technology research, e.g. analysis of grain composition and intergrowths or determination of rare earth element distributions. The simultaneous measurement of a big array of pixel enables a fast overview over a large region of the sample with first results becoming visible almost immediately. Together with the PIXE-PIGE (particle-induced gamma-emission) implementation at the classical micro-beamline at HZDR (~3 µm resolution) this new approach allows analysis of most of the elements of interest in mineralogy and resource technology research.
First results concerning lateral resolution and detection limits of geological samples are encouraging. Due to the low background in the PIXE spectra investigation of the lateral distribution of trace elements is possible in unrivalled time.

[1] O. Scharf et al., Anal. Chem., 2011, . 83, 2532.
[2] I. Ordavo et al., NIM A, 2011, . 654, 250.