How It Works
An ESEM employs a scanned electron beam and electromagnetic lenses to focus and direct the beam on the specimen surface in an identical way as a conventional SEM. A very small focused electron spot (probe) is scanned in a raster form over a small specimen area. The beam electrons interact with the specimen surface layer and produce various signals (information) that are collected with appropriate detectors. The output of these detectors modulates, via appropriate electronics, the screen of a monitor to form an image that corresponds to the small raster and information, pixel by pixel, emanating from the specimen surface. Beyond these common principles, the ESEM deviates substantially from a SEM in several respects, all of which are important in the correct design and operation of the instrument. The outline below highlights these requirements and how the system works.
Read more about this topic: Environmental Scanning Electron Microscope
Famous quotes containing the word works:
“They commonly celebrate those beaches only which have a hotel on them, not those which have a humane house alone. But I wished to see that seashore where man’s works are wrecks; to put up at the true Atlantic House, where the ocean is land-lord as well as sea-lord, and comes ashore without a wharf for the landing; where the crumbling land is the only invalid, or at best is but dry land, and that is all you can say of it.”
—Henry David Thoreau (1817–1862)