What is shadowing in XRF mapping?

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Multiple Choice

What is shadowing in XRF mapping?

Shadowing occurs when something blocks the detector’s line of sight to part of the sample during mapping. In XRF mapping, the detector collects fluorescence from every point, so if a feature of the sample or surrounding hardware sits between the sample area of interest and the detector, photons from that region can be blocked. The result is fewer counts coming from that region, making it appear under-sampled or missing in the map. This can distort the apparent distribution of elements and mimic a low-concentration area even if the material is uniform. To avoid shadowing, adjust the geometry so there’s a clear line of sight—tilt or elevate the sample, reposition the detector or stage, or remove obstructive items from the field of view. Other terms describe different issues: increased background noise from scattering is general noise, not a blocked view; over-sampling refers to data density rather than obstruction; calibration artefacts in energy relate to the energy scale, not visibility between sample and detector.

Shadowing occurs when something blocks the detector’s line of sight to part of the sample during mapping. In XRF mapping, the detector collects fluorescence from every point, so if a feature of the sample or surrounding hardware sits between the sample area of interest and the detector, photons from that region can be blocked. The result is fewer counts coming from that region, making it appear under-sampled or missing in the map. This can distort the apparent distribution of elements and mimic a low-concentration area even if the material is uniform.

To avoid shadowing, adjust the geometry so there’s a clear line of sight—tilt or elevate the sample, reposition the detector or stage, or remove obstructive items from the field of view. Other terms describe different issues: increased background noise from scattering is general noise, not a blocked view; over-sampling refers to data density rather than obstruction; calibration artefacts in energy relate to the energy scale, not visibility between sample and detector.

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