Electron Source 



Condenser Coil 

 Specimen Mount 

 Objective Coil 



Port tor intermediote Viewing 



Vacuum Pump 



Projection Coil 



Ports tor Viewing Fi-nol Enlarged Image 

 Fluorescent Screen or Photographic Plate 



Figure 8-2. Simplified drawing of electron microscope, taken from "Electron Microscope" 

 prepared by R.C.A. Manufacturing Company, Camden, N. J. 



it is possible to select the most interesting part of the specimen and to move it 

 into position to be magnified further by the projection-lens coil. 



Six observation windows enable a number of spectators to view the image 

 simultaneously. With the choice of a selected field of view and the magnification 

 adjusted to the desired value, the fluorescent screen is raised, exposing a photo- 

 graphic plate to the electrons. This plate is carried in a holder in the vacuum 

 system of the microscope. Magnifications of 1000 to 20,000 diameters are pos- 

 sible, and the definition of the photograph is sufficiently clear to allow further 

 optical enlargement to full useful magnification. 



43 



