What Is an SEM?
An electron microscope uses electrons to "probe" a specimen. Electrons have particular wavelengths associated with them depending upon their energies. These wavelengths are much smaller than the wavelengths of light. Therefore, they can resolve, or "see" much finer details. Theoretically, one can see details on the order of Angstroms (10 -10 meters!).
Instead of light waves, we use electron waves!
So, how do we use these electrons?
First, electrons are ejected off a fine filament running a high voltage (usually 10kV to 30kV). Then, they travel down a long "gun" where various magnetic lenses condense them into a narrower beam. Finally, they are focused toward one final spot (hopefully on the specimen under investigation!).
The electrons can then "interact" with the specimen in a variety of ways.
West Georgia Microscopy Center Department of Geosciences University of West Georgia 1601 Maple Street Carrollton, GA 30118 (678) 839-6479
