A platinum filament covered with a mixture of oxides has been used to replace the tungsten filament in the RCA model EMU‐2 electron microscope. This unit originally was used on an Akashi electron microscope. Since the filament operates at a low temperature, evaporation of the filament itself is very slow. The electron source is very small. The drift of illumination is small and the field of illumination is quite uniform.

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3.
The filament coating material was obtained from Akashi, Naka 8th Bldg, Marunouchi, Tokyo, Japan. They have this to say about the coating. “The powder is a mixture of BaCO3, SrCO3, and CaCO3, and nitrocellulose which acts as a binder.”
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© 1960 The American Institute of Physics.
1960
The American Institute of Physics
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