Characterization of a system that combines energy dispersive X-ray diffraction with X-ray fluorescence and its potential applications in archeometry

摘要

We report a proof of concept constructing an experimental setup to explore the imaging capability of a single X-ray detector, simulating a pixelated X-ray detector, to measure EDXRF (Energy Dispersive X-ray Fluorescence) and EDXRD (Energy Dispersive X-ray Diffraction) image spectra simultaneously. Combining a conventional rotating anode Cu X-ray source and assembling a single X-ray detector (Si-PIN Amptek, 139eV at 5.98keV) on a computer controlled XY stage, a proxy of an imaging X-ray detector was constructed for the measurement of simultaneous EDXRD and EDXRF of the same spot of a sample. The main advantages of this setup are the virtual need for sample preparation and the simultaneous XRF-XRD measurements of the same spot, enabling a combined and consistent analysis of a sample. The time consumed in an analysis using this setup is largely due to the need for acquiring multiple (several hundred) single spectra, which can be compensated, by using a variable acquisition time, depending on the count rate, exploring the high dynamic range of the X-ray emission during data acquisition. A Python code was written for offline data filtering and analysis. Using a simple geometrical model, d-spacings were calculated, and the model predictions were superimposed to the ED (Energy Dispersive) surface plots with good agreement. The instrument proved to work according to expectations and helped set the main experimental parameters for a more compact and portable setup under development.