Figure 1
Many of the biologically relevant trace metals have rather low fluorescence yields, giving rise to poor signal-to-noise in individual projections. Shown here is the fluorescence yield (Krause, 1979BB22) of several elements plotted as a function of the emission energies. The competing process, Auger electron emission, is not well suited to elemental detection in thick biological specimens because Auger electrons do not escape at their original element-signalling energy except from regions well within 100 nm of the sample's surface.  [article HTML]

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