Scanning electron microscope

Unlike the TEM, where electrons of the high voltage beam carry theNJM3770AFM2

 image of the specimen, the electron beam of the scanning electron microscope does not at any time carry a complete image of theBA5938

 specimen. The SEM produces images by probing the specimen with a focused electron beam that is scanned across a rectangular area of the specimen (raster scanning). At each pointCSM14083DN

 on the specimen the incident electron beam loses some energy, and that lost energy is converted into other forms, such as heat, emission of low-energy secondary electrons, light emissionTA7270P

 (cathodoluminescence) or X-ray emission. The display of the SEM maps the varying intensity of any of these signals into the image in a position corresponding to the position of the beam on the specimen whenMAX192

 the signal was generated. In the SEM image of an ant shown at right, the image was constructed from signals produced by a secondary electron detector, the normal or conventional imaging mode in most SEMs.