scanning electron microscope

noun

1. a device in which the specimen is examined point by point directly in a moving electron beam, and electrons reflected by the specimen are used to form a magnified, three-dimensional image on a television screen. Abbreviation: SEM

noun

1. a type of electron microscope that produces a three-dimensional image

n.

1. An electron microscope that forms a three-dimensional image on a cathode-ray tube by moving a beam of focused electrons across an object and reading both the electrons scattered by the object and the secondary electrons produced by it.

1. An electron microscope that moves a narrowly focused beam of electrons across an object and detects the patterns made by the electrons scattered by the object and the electrons knocked loose from the object. From these patterns a three-dimensional image of the object is created.