DHY 230 Lecture Notes - Thermionic Emission, Bremsstrahlung, Collimator
Document Summary
, the filament heats up , and thermionic emission occurs. When exposure button is activated: the electrons strike the tungsten target , X - rays produced at x - ray tube anode the electrons are accelerated from cathode to anode and their kinetic energy is converted to x-rays and heat. Most of the x-rays are general (bremsstrahlung) or characteristic /small portion) Plmary beam exists tobehead after filtration / collimation absorbed , scattered. Goal of radiographic process depends on : Quality , quantity , density what is an ideal. Image? incoming energy of beam + how it is attenuated. {g. contrast : separation between light / dark clow contrast = dark) ( kvp) ( low density = bright) balancing these is key to an ideal. An image with mostly black / white and few grays = high contrast. Ray beam quality image low energy low frequency.
