You searched for: “sem
electron scanning microscope, scanning electron microscope, SEM
An instrument similar to an electron microscope in that a beam of electrons is used to scan the surface of a specimen.

The beam is moved in a point-to-point manner over the surface of the specimen and these electrons are deflected collected, accelerated, and directed against a scintillator.

The large number of photons that are created are converted into an electric signal which, in turn, modulates the beam scanning the surface of the specimen.

This entry is located in the following units: electro-, electr-, electri- (page 52) -tron, -tronic, -tronics + (page 4)