Scanning x-ray fluorescence experiment cartoon

This cartoon is of a scanning x-ray fluorescence experiment, using an image of thorium enrichment in a fossilised fish. The two images, those of the fossil and the fluorescence map, are taken from data published here. The x-ray fluorescence spectra are simulated and are not the original data that produced the fluorescence map. They contain signal from calcium, phosphorus, thorium, and uranium. Note that as the incident x-rays (17.2 keV) pass over the thorium-rich parts of the fossil, the signal at 12.97, 15.62, and 16.2 keV increases, while the cartoon fluorescence ‘plume’ lights up from blue to green, yellow, and red.