File:Original cavity magnetron, 1940 (9663811280).jpg

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English: Microwave cavities in original cavity magnetron tube, developed by John Randall (1905-1984) and Harry Boot (1917-1983) at Birmingham University in 1940. This was contained inside a vacuum tube. A heated cathode extended up the central axis, which emitted electrons, and a permanent magnet embracing the tube created a magnetic field along the axis of the tube. The magnetic field caused the electrons to circle in bunches within the central cavity of the tube, inducing microwave oscillations in the 6 peripheral cylindrical cavities.
The cavity magnetron was the first practical device for producing power at centimeter wavelengths. It enabled the development of radars that could produce clear images of distant objects by bouncing microwaves off their targets. These played a significant role in World War 2. Please note: this image has not been fully finished.
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Original cavity magnetron, 1940

Author Science Museum London / Science and Society Picture Library

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This image, originally posted to Flickr, was reviewed on 3 September 2013 by the administrator or reviewer File Upload Bot (Magnus Manske), who confirmed that it was available on Flickr under the stated license on that date.

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Date/TimeThumbnailDimensionsUserComment
current15:05, 29 July 2021Thumbnail for version as of 15:05, 29 July 2021861 × 863 (254 KB)Maury Markowitz (talk | contribs)Cropped 13 % horizontally, 31 % vertically using CropTool with precise mode.
10:24, 3 September 2013Thumbnail for version as of 10:24, 3 September 2013988 × 1,250 (345 KB)File Upload Bot (Magnus Manske) (talk | contribs)Transferred from Flickr by User:Mrjohncummings

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