= Scanning electron microscope
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= Scanning electron microscopy
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= SEM
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A <scanning electron microscope> scans a focused <Electron> probe across a specimen and assigns a detector signal to each probe position. <Secondary electrons> leaving the irradiated region often reveal surface relief; <backscattered electrons> can provide composition-dependent contrast. Image brightness records the selected signal, rather than a transmitted projection enlarged by two lenses. Display enlargement is therefore set by the ratio of display width to scanned specimen width. Surface geometry and composition both affect brightness.<Scanning Electron Microscopes (SEM) by JEOL>[JEOL, Why can a specimen be observed with an electron? and Various Function of SEM: secondary and backscattered signals]{ref}
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