![]() The projector throws its image onto a fluorescent screen which may be substituted by a photographic plate to make a permanent record. The electron beam coming out of the specimen passes to the objective lens, which has high power and forms the intermediate magnified image. ![]() In contrast, transparent regions are brighter. The denser regions in the specimen scatter more electrons and therefore appear darker in the image since fewer electrons strike that area of the screen. The condenser lenses focus the electronic beams through the specimen and electrons are scattered depending upon the thickness or refractive index of different parts of the specimen. A large voltage is applied between the cathode (the tungsten filament) and the anode, which excites the electrons and it travels with high velocity towards the condenser lens. ![]() ![]() The electronic beam is obtained from a heated tungsten filament which generates electrons. Slices thus prepared are then mounted on a metal slide.
0 Comments
Leave a Reply. |