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Coolidge tube, United States, 1920

Science Museum, London


Free to use with attribution CC BYCredit: Science Museum, London
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American physicist William Coolidge (1832-1919) patented his ‘hot cathode’ tube in 1913. The cathode was a heated, electron-emitting tungsten filament. It produced a high output of X-rays that did not fluctuate and were easily adjusted. This eliminated many problems of the older so-called ‘gas tubes’. Combined with more reliable power supplies, it allowed X-ray techniques to become standardised and reproducible. The fins at the end of the tube disperse the heat generated in the tungsten anode which the larger currents use. maker: General Electric Place made: United States



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Coolidge tube, United States, 1920. Credit: Science Museum, London. CC BY

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