- Castle Yankee
Castle Yankee was the code name given to one of the tests in the
Operation Castle series of American nuclear tests.Jughead
Yankee was originally intended to be a test of a simplified and lightened bomb version (the TX-16, or "emergency capability" EC-16) of the large and complex
cryogenic device (the first successful multi-stage fusion device) tested inIvy Mike . A small number of EC-16s were produced on an emergency basis to provide a stop-gapthermonuclear weapon capability in response to the Russian nuclear weapons program.The test device, code-named "Jughead", had been prepared as a backup in case the non-cryogenic "Shrimp" fusion device (first tested in
Castle Bravo ) failed to work. The test of "Jughead" was cancelled when the Bravo device was successful, and the few EC-16s which were actually built were withdrawn and dismantled.Runt II
Jughead was replaced in the Yankee test by the so-called "Runt II" device (the TX-24 bomb, initially the "emergency capability" EC-24), a modified form of the "Runt" device (the TX-17/EC-17) tested in
Castle Romeo . Externally identical, the principal difference between them was in the fuel for the fusion stage. While Runt used naturallithium (with 7.5% of the Lithium-6isotope ), Runt II used the same partially enriched lithium (approximately 40% Lithium-6) as the "Shrimp" device tested in Bravo.It was detonated on
May 5 ,1954 , atBikini Atoll of theMarshall Islands , on a barge moored in the middle of the crater from theCastle Union test.Although it has been predicted to produce a yield of 6 to 10
megaton s, it actually produced a yield of 13.5 megatons, the second-largest ever yield in a U.S. fusion weapon test. Like theIvy Mike , Bravo and Romeo tests, a large percentage of the yield was produced by fast fission of the naturaluranium "tamper"; 7 megatons of the yield were from this source. The other 6.5 megatons were from fusion reactions; this increase was due to the different fusion fuel. This fusion yield was the largest to date, and set a record that stood for several years.External links
* [http://www.archive.org/details/CastleCommandersReport1954 Downloadable/Streamable Declassified Film: Operation Castle Commanders Report, at the Internet Archive]
* [http://www.archive.org/details/MilitaryEffectsStudiesonOperationCastle1954 Downloadable/Streamable Declassified Film: Military Effects Studies Operation Castle, at the Internet Archive]
* [http://nuclearweaponarchive.org/Usa/Tests/Castle.html Operation Castle]References
* Chuck Hansen, "U. S. Nuclear Weapons: The Secret History" (Arlington: AeroFax, 1988)
Wikimedia Foundation. 2010.
