any analytical technique which involves the generation and evaluation of secondary electrons (and to a lesser extent back scattered electrons) by a finely focused electron beam (typically 10 nm or less) for high resolution and high depth of field imaging, analüütiline tehnika, mille puhul kitsalt fokuseeritud elektronkiire (tavaliselt 10 nm või vähem) abil tekitatakse suure sügavusteravusega kujutis