alfa filter

One of the in-column type energy filters, which is installed between the intermediate and projector lenses in a TEM. The "alfa filter," whose principle of energy dispersion is the same as that of the omega filter, consists of two electromagnets instead of four electromagnets in the omega filter. Since the trajectory of electrons passing through the alfa filter takes the shape of a letter "alfa," this is called alfa filter. Its energy dispersion is ～0.7 μm/eV, which is smaller than that of the omega filter.

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