SEM

SEM produces an image from the electrons released from the object

It examines the structure of microorganisms

To create an image , SEM scans narrow tapered electron beam back and forth over the specimen

When beam strikes the surface of atoms , a tiny shower of electrons is discharged called secondary /backscattered/X-rays

These are detected by a special detector

Secondary electrons entering the detector strike a scintillator causing it to emit light which a photomultiplier converts to an electric signal and amplifies

The signal is sent to a cathode ray tube and produces an image.