PositronDiscovery

Forfatter/Opretter:

Carl D. Anderson (1905–1991)

Kredit:

Anderson, Carl D. (1933). "The Positive Electron". Physical Review 43 (6): 491–494. DOI:10.1103/PhysRev.43.491.

Shortlink:

https://dkwiki.dk/b/135fe

kilde:

Wikimedia Commons

størrelse:

2408 x 2374 Pixel (1998934 Bytes)

beskrivelse:

Cloud chamber photograph of the first positron ever observed. The thick horizontal line is a lead plate. The positron entered the cloud chamber in the lower left, was slowed down by the lead plane, and curved to the upper left. The curvature of the path is caused by an applied magnetic field that acts perpendicular to the image plane. The higher energy of the entering positron resulted in lower curvature of its path.
Original caption: A 63 million volt positron (H_ρ = 2.1×10⁵ gauss-cm) passing through a 6 mm lead plate and emerging as a 23 million volt positron (H_ρ = 7.5×10⁴ gauss-cm). The length of this latter path is at least ten times greater than the possible length of a proton path of this curvature.

Licens:

Public domain

Kommentar på licensen:

Obtained from American Physical Society, March 5, 2008. The copyright for the periodical containing this picture, if renewed, would have had to be renewed in 1960 or 1961. I checked the Catalog of copyright entries for Periodicals in 1960 and 1961, http://onlinebooks.library.upenn.edu/cce/, but The Physical Review is not listed there. Therefore, the copyright on the entire issue of The Physical Review, including this picture, has expired.