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A new parallel-beam wavelength dispersive (PB-WDS) X-ray emission spectrometer was constructed at the external proton beamline at the Microanalytical Centre of the Joˇzef Stefan Institute in Ljubljana. The spectrometer combines polycapillary X-ray optics for efficient X-ray collection with diffraction on a flat crystal analyzer and achieves energy resolution in the eV range. The whole set-up is enclosed within a He bag to be able to operate in the tender X-ray energy range. The basic design is described together with the results of characterization measurements yielding the main operation characteristics. Finally, an application for the micro-PIXE analysis of biological tissue is demonstrated exploiting both spatial and energy resolution of the new set-up.

Wavelength-dispersive X-ray spectrometry is used to examine the influence of multiple ionization satellites induced by 3–5 MeV energy helium ion beams upon the accuracy of particle-induced X-ray emission analysis (PIXE). The work extends our prior study of elements magnesium, aluminum and silicon and their oxides to elements phosphorus, chlorine, potassium, calcium, titanium and chromium and, for the latter two, their oxides. Fitting of the spectra with Voigtian peaks enables construction of a database that comprises the mean energies and the relative intensities of up to four distinct satellite groupings. This database provides an empirical means for inclusion of one peak per satellite group when modelling energy-dispersive spectra. This is a useful step towards improving the accuracy of PIXE analysis of materials using helium beams ; an example of this is provided using a spectrum recorded by the Curiosity rover on Mars.

Application of laboratory-based X-ray analytical techniques that are capable of a reliable characterization of the chemical state of sulfur within bulk battery cathode in parallel with electrochemical characterization is essential for further development of lithium-sulfur batteries. In this work, MeV proton-induced X-ray emission (XES) sulfur measurements were performed in ex situ mode on laboratory-synthesized sulfur standards and precycled battery cathodes. The average sulfur charge was determined from the energy shift of the Kα emission line and from the spectral shape of the Kβ emission spectrum. Finally, operando Kα XES measurements were performed to monitor reduction of sulfur within battery cathode during discharge. The experimental approach presented here provides an important step toward more routine laboratory analysis of sulfur-based battery systems and also other sulfur-neighboring low-Z bulk materials with emission energies in the tender X-ray range.