gun: The electrons are generated and accelerated to
the required high energy.
system: A set-up of different magnetic
lenses and apertures
makes it possible to get either a parallel beam (micro probe for
TEM) or a convergent beam with selected convergence angles (nano
probe for STEM and CBED). Furthermore, the beam can be scanned (STEM)
or tilted (DF-TEM).
lens: Most important lens in the microscope since it generates
the first intermediate image, the quality of which determines the
resolution of the final image.
lens: Switching between imaging and diffraction mode.
lenses: Further magnification of second intermediate image
(image or diffraction pattern, respectively).
observation: Images and diffraction pattern can directly
be observed on the viewing screen in the projection chamber or
a TV camera
mounted below the microscope column. Images can be recorded on
negative films, on slow-scan CCD cameras or on imaging plates.
system: Because of strong interactions of electron with
matter, gas particles must be absent in the column. The required
high vacuum is maintained by a vacuum system typically comprising
a rotary pump (pre-vacuum pump), a diffusion pump and one or
more ion getter pumps.