Wavelength-dispersive X-ray spectroscopy
Wavelength-dispersive X-ray spectroscopy (WDXS or WDS) is a non-destructive analysis technique used to obtain elemental information about a range of materials by measuring characteristic x-rays within a small wavelength range. The technique generates a spectrum in which the peaks correspond to specific x-ray lines, and elements can be easily identified.
Source: Wikipedia — Wavelength-dispersive X-ray spectroscopy (CC BY-SA 4.0)