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Summary
| Description |
The first betatron, a particle accelerator that accelerates electrons, built at University of Illinois in 1940 by Donald W. Kerst, seen at right working on the pole pieces. It consisted of a 4 ton electromagnet with a donut-shaped vacuum chamber circling the pole piece and produced 24 Mev electrons. |
| Date | |
| Source | Retrieved January 2, 2015 from Electronics magazine, McGraw-Hill Publishing Co., New York, Vol. 15, No. 2, February 1942, p. 22 on http://www.americanradiohistory.com |
| Author | Unknown author |
| Permission (Reusing this file) |
This 1942 issue of Electronics magazine would have the copyright renewed in 1970. 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 1969, 1970, and 1971 show no renewal entries for Electronics. Therefore the magazine's 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. Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 13:57, 2 January 2015 | | 701 × 832 (172 KB) | Chetvorno | User created page with UploadWizard |
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