As far as I know this method allows both getting surface image and then taking refractogram from a very specific area of the sample. Can you please explain in simple words how does it work?
The electron beam shines through the sample, the inhomogeneous absorption of electrons by different parts of the sample gives a two-dimensional picture of the density distribution of the transmitted electron beam. The flow passing through the sample is then focused on the recording surface by magnetic electronic lenses (electronic optics) in an enlarged size. As a recording surface, fluorescent screens coated with a phosphor layer, photographic film or photographic plate, or charge-coupled devices are used.
But how come electron beam give the same type of data as X-ray?
What types of signals generated in an electron microscope are used in analytical transmission microscopy?