File:Megavolt x-ray tube - St Bartholomew's Hospital 1937.jpg
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Megavolt x-ray machine London
Summary
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| Description |
English: A megavolt x-ray tube for radiotherapy installed at St. Bartholomew's Hospital, London in 1937. It was 30 feet long and weighed 10 tons. External beam radiotherapy began in the early 1900s with low voltage (<150 kV) x-ray tubes. It was found that low voltage tubes could treat superficial tumors, but more penetrating radiation was needed to reach tumors deep in a patient's body, motivating the creation of orthovoltage (200-500 kV) machines in the 1920s, then megavoltage (>1 million volts) machines in the 1930s. This machine was used until 1960. Today linear accelerators have mostly superseded x-ray radiotherapy. Caption: Said to be the world's largest, this ten-ton thirty foot tube of St. Bartholomew's Hospital, London, is built within walls of barium concrete for protection against stray rays. The patient converses by means of the microphone with doctors, who observe him with a mirror system |
| Date | |
| Source | Retrieved November 23, 2015 from "World's Largest X-ray Tube" in Electronics magazine, McGraw-Hill Publishing Co., New York, Vol. 10, No. 3, March 1937, p. 36 on http://www.americanradiohistory.com |
| Author | Unknown author |
| Permission (Reusing this file) |
This 1937 issue of Electronics magazine would have the copyright renewed in 1965. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. Search of the Renewals for Periodicals for 1964, 1965, and 1966 show no renewal entries for Electronics. Therefore the copyright was not renewed and it is in the public domain. |
Licensing
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This work is in the public domain because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the copyright was not renewed. For further explanation, see Commons:Hirtle chart and the copyright renewal logs.
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 05:40, 24 November 2015 | | 383 × 323 (39 KB) | Chetvorno (talk | contribs) | User created page with UploadWizard |
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