XRF Spectrum of Magnesium taken with an Olympus/Innov-X DP-2000 X-Ray Fluorescence spectrometer with a Si-Drift detector (Hardware settings: Source: Rh; Voltage: 15 kV, Analytical Mode-FP algorithm, acquisition time 34s). Note that the region of of 2.5 to 12.5 keV, not shown, is complicated with peaks (e.g., target and diffraction lines) that are not fluorescence from the magnesium.
Note that irradiation of the light elements that are weak absorbers affords a backscatter pattern. This is observed for pure magnesium for the a-2000 analyzer (Si-Pin detector) at atmospheric pressure, in which case the emission lines for Mg are too weak to see above the noise (below). A similar pattern is observed for organics and light inorganics (elements with Atomic # <15).
XRF Background (Light Matrix) Spectrum, using a disk of Magnesium, taken with an Innov-X a-2000 X-Ray Fluorescence spectrometer with a Si-PiN detector (Hardware settings: Source: Ta; Voltage: 40 kV; Current: 24 uA; Filter: 250 uM Cu, Analytical Mode-FP algorithm, acquisition time 34s).