Castle Union

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Castle Union
Castle Union.jpg
The Castle Union test of the Mark 14 design
Information
CountryUnited States
Test series Operation Castle
Test site Bikini Atoll
Date26 April 1954;70 years ago (1954-04-26)
Test type Atmospheric
Yield6.9 megatons of TNT
Test chronology
Mark 14 nuclear bomb Mk 14 nuclear bomb.jpg
Mark 14 nuclear bomb

Castle Union was the code name given to one of the tests in the Operation Castle series of United States nuclear tests. It was the first test of the TX-14 thermonuclear weapon (initially the "emergency capability" EC-14), one of the first deployed U.S. thermonuclear bombs.

An "Alarm Clock" device is a "dry" fusion bomb, using lithium deuteride fuel for the fusion stage of a "staged" fusion bomb, unlike the cryogenic liquid deuterium of the first-generation Ivy Mike fusion device.

It differed from the Castle Romeo "Runt" device, tested shortly before, in using highly enriched lithium (approximately 95% lithium-6; natural lithium is a mixture of lithium-6 and lithium-7 isotopes). The "Runt" device had 7.5% lithium-6 in the fusion fuel.

The test took place on 26 April 1954 at Bikini atoll of the Marshall Islands, on a barge moored in the lagoon, off Yurochi island. The yield of 6.9 megatons of TNT was roughly double the predicted 3-4 megatons. Although the barge had been moored in over 160 feet (49 m) of water, the test left a crater 3,000 feet (910 m) in diameter and 90 feet (27 m) deep in the bottom of the lagoon.

Like the Ivy Mike, Castle Bravo, and Castle Romeo tests, a large percentage of the yield was produced by fast fission of the natural uranium tamper, which contributed to the extensive fallout caused by these tests.

As the highly enriched lithium was both expensive and scarce at the time, it limited the number of these weapons that could be produced. The "Runt" design tested in Castle Romeo and Castle Yankee was preferred for deployment.

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  3. Staged thermonuclear weapons are arrangements of two or more "stages", most usually two. The first stage is normally a boosted fission weapon as above. Its detonation causes it to shine intensely with X-rays, which illuminate and implode the second stage filled with a large quantity of fusion fuel. This sets in motion a sequence of events which results in a thermonuclear, or fusion, burn. This process affords potential yields up to hundreds of times those of fission weapons.
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<span class="mw-page-title-main">Operation Castle</span> Series of 1950s US nuclear tests

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<span class="mw-page-title-main">Castle Bravo</span> 1954 U.S. thermonuclear weapon test in the Marshall Islands

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<span class="mw-page-title-main">Mark 24 nuclear bomb</span> American thermonuclear bomb design

The Mark 24 nuclear bomb was an American thermonuclear bomb design, based on the third American thermonuclear bomb test, Castle Yankee. The Mark 24 bomb was tied as the largest weight and size nuclear bomb ever deployed by the United States, with the same size and weight as the Mark 17 nuclear bomb which used a very similar design concept but unenriched lithium.

<span class="mw-page-title-main">Mark 14 nuclear bomb</span> Thermonuclear gravity bomb

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Sundial was the codename of one of two massive nuclear bombs planned for testing by the University of California Radiation Laboratory, Livermore Branch as part of a classified American weapons project in the early 1950s. Announced by Edward Teller at a meeting of the General Advisory Committee of the Atomic Energy Commission, it was intended to have a yield of 10 gigatons of TNT, while its counterpart, Gnomon, was intended to have a yield of 1 gigaton.

References

11°41′02″N165°24′36″E / 11.68389°N 165.41000°E / 11.68389; 165.41000