The mushroom cloud from the Mike shot.

Ivy Mike was the code name given to the first successful test of a fusion device, detonated on October 31, 1952 (US time — November 1 local time) by the United States on Enewetak, an atoll in the Pacific Ocean, as part of Operation Ivy. The device was the first full test of the Teller-Ulam design for a "staged" fusion bomb. Image File history File links Download high resolution version (800x637, 55 KB) XX-11 IVY MIKE, was fired on Enewetak by the United States on October 31, 1952. ... Image File history File links Download high resolution version (800x637, 55 KB) XX-11 IVY MIKE, was fired on Enewetak by the United States on October 31, 1952. ... The atomic bombing of Nagasaki, Japan on August 9, 1945 A mushroom cloud is a distinctive mushroom-shaped cloud of smoke, flame, or debris resulting from a very large explosion. ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ... October 31 is the 304th day of the year (305th in leap years) in the Gregorian Calendar, with 61 days remaining. ... 1952 (MCMLII) was a Leap year starting on Tuesday (link will take you to calendar). ... November 1 is the 305th day of the year (306th in leap years) in the Gregorian Calendar, with 60 days remaining. ... Aerial view of Enewetok and Parry. ... An atoll is a type of low, coral island found in tropical oceans and consisting of a coral-algal reef usually surrounding an interior body of water called a lagoon or peninsula. ... Operation Ivy was the eighth series of American nuclear tests, coming after Tumbler-Snapper and before Upshot-Knothole. ... The basics of the Teller-Ulam configuration: a fission bomb uses radiation to compress and heat a separate section of fusion fuel. ...

Due to its physical size and fusion fuel type (cryogenic liquid deuterium) the poop device was not itself suitable for use as a thermonuclear weapon. A simplified and lightened bomb version (the EC-16) was prepared, and scheduled to be tested in Castle Yankee, as a backup in case the non-cryogenic "Shrimp" fusion device (tested in Castle Bravo) failed to work; that test was cancelled when the Bravo device was successful. Cryogenics is the study of very low temperatures or the production of the same, and is often confused with cryobiology, the study of the effect of low temperatures on organisms, or the study of cryopreservation. ... Deuterium, also called heavy hydrogen, is a stable isotope of hydrogen with a natural abundance in the oceans of planet Earth of approximately one atom in 6500 of hydrogen (~154 PPM). ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, in 1945 lifted nuclear fallout some 18 km (60,000 feet) above the epicenter. ... Castle Yankee was the code name given to one of the tests in the Operation Castle series of American nuclear tests. ... A black and white photograph of the Castle Bravo mushroom cloud. ...

Device design and preparations

A view of the Sausage device casing, with its diagnostic and cryogenic equipment attached. The long pipes would receive the first bits of radiation from the primary and secondary ("Teller light") just as the device was detonated.

The "Mike" device was essentially a very large cylindrical thermos flask for holding the cryogenic deuterium fusion fuel, with a regular fission bomb (the "primary") at one end; the latter was used to create the conditions needed to start the fusion reaction. Image File history File links Download high resolution version (1024x746, 127 KB) A photograph of the Sausage device from the Ivy Mike nuclear test, 1952. ... Image File history File links Download high resolution version (1024x746, 127 KB) A photograph of the Sausage device from the Ivy Mike nuclear test, 1952. ... Lunchbox and vacuum bottle owned by Harry S. Truman A vacuum flask or Thermos flask is a bottle that reduces heat transfer from the inside to the outside and conversely to a minimum, and therefore keeps warm drinks warm and refrigerated drinks cold. ... For the generation of electrical power by fission, see Nuclear power plant An induced nuclear fission event. ...

The primary stage was a TX-5 boosted fission bomb in a separate space atop the assembly (so it would not freeze, rendering it inoperable). The "secondary" fusion stage used liquid deuterium despite the difficulty of handling this material, because this fuel simplified the experiment, and made the results easier to analyze. Running down the center of the flask which held it was a cylindrical rod of plutonium (the "sparkplug") to ignite the fusion reaction. Surrounding this assembly was a five-ton natural uranium "tamper". The interior of the tamper was lined with sheets of lead and polyethylene foam, which formed a radiation channel to conduct X-rays from the primary to secondary. (The function of X-rays was to hydrodynamically compress the secondary, increasing the density and temperature of the deuterium to the levels needed to sustain the thermonuclear reaction, and compressing the sparkplug to supercriticality ignition.) The outermost layer was a steel casing 10-12 inches thick. The entire "Sausage" (as it was nicknamed) assembly measured 80 inches in diameter and 244 inches in height and weighed about 60 tons. General Name, Symbol, Number plutonium, Pu, 94 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass (244) g·mol−1 Electron configuration [Rn] 5f6 7s2 Electrons per shell 2, 8, 18, 32, 24, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Atomic mass 238. ... For PB or pb as an abbreviation, see PB. General Name, Symbol, Number lead, Pb, 82 Chemical series poor metals Group, Period, Block 14, 6, p Appearance bluish white Atomic mass 207. ... This article or section does not cite its references or sources. ... Radiation in physics is the process of emitting energy in the form of waves or particles. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... A sphere of plutonium surrounded by neutron-reflecting blocks of tungsten carbide. ...

The entire Mike device (including cryogenic equipment) weighed 82 tons, and was housed in a large corrugated-aluminium building called a "shot cab" which was set up on the Pacific island of Elugelab, part of the Enewetak atoll. Elugelab Island was part of the Enewetak Atoll in the Marshall Islands before it was vaporized by the very first test of the hydrogen bomb in 1952 as part of Operation Ivy. ... Aerial view of Enewetok and Parry. ...

A 9,000-foot long artificial causeway connected the islands of Elugelab, Teiter, Bogairikk, and Bogon. Atop this causeway was an aluminium-sheathed plywood tube (named a "Krause-Ogle box") filled with helium ballonets. This allowed gamma and neutron radiation to pass uninhibited to an unmanned detection station housed in a bunker on Bogon. General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ... Toy constructed from plywood. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ... Gamma (uppercase Γ, lowercase γ) is the third letter of the Greek alphabet. ... This article or section does not cite its references or sources. ... Radiation in physics is the process of emitting energy in the form of waves or particles. ...

In total, 9,350 military and 2,300 civilian personnel were involved in the Mike shot. A large cryogenics plant was installed on Parry Island, at the South end of the Eniwetak atoll, to produce the liquid hydrogen (used for cooling the device) and deuterium needed for the test.

Detonation

Enewetak Atoll, before Mike shot. Note island of Elugelab on left.

Enewetak Atoll, after Mike shot. Note crater on left.

The test was carried out 0715 hours local time on November 1, 1952; it produced a yield of 10.4 megatons (10.4 million tons of TNT). However, 77% of the final yield came from fast fission of the uranium tamper, which meant that the device produced large amounts of fallout. Image File history File linksMetadata Download high resolution version (800x620, 258 KB) Island of Elugelab, Enewetak Atoll, Marshall Islands, site of the U.S. Ivy Mike hydrogen bomb test (1952), before detonation. ... Image File history File linksMetadata Download high resolution version (800x620, 258 KB) Island of Elugelab, Enewetak Atoll, Marshall Islands, site of the U.S. Ivy Mike hydrogen bomb test (1952), before detonation. ... Image File history File linksMetadata Download high resolution version (780x610, 234 KB) A crater is all that remains of the island of Elugelab, Enewetak Atoll, Marshall Islands, site of the U.S. Ivy Mike hydrogen bomb test (1952), after detonation. ... Image File history File linksMetadata Download high resolution version (780x610, 234 KB) A crater is all that remains of the island of Elugelab, Enewetak Atoll, Marshall Islands, site of the U.S. Ivy Mike hydrogen bomb test (1952), after detonation. ... November 1 is the 305th day of the year (306th in leap years) in the Gregorian Calendar, with 60 days remaining. ... 1952 (MCMLII) was a Leap year starting on Tuesday (link will take you to calendar). ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ... Trinitrotoluene (TNT) is an explosive. ... Map of hypothetical fallout dispersal after a large-scale nuclear attack against the United States. ...

The fireball was over 3 miles wide, and the mushroom cloud rose to an altitude of 57,000 feet in less than 90 seconds. One minute later it had reached 108,000 feet, before stabilizing at 120,000 feet, with the top eventually spreading out to a diameter of 100 miles (the stem was 20 miles wide).

The blast created a crater 6,240 feet in diameter and 164 feet deep where Elugelab had once stood; the blast and water waves from the explosion (some waves up to twenty feet high) stripped the test islands clean of vegetation, as observed by a helicopter survey within 60 minutes after the test, by which time the mushroom cloud and steam had been blown away. Irradiated coral debris fell upon ships stationed 30 miles from the blast, and the immediate area around the atoll was heavily contaminated for some time.

The entire shot was documented by the filmmakers at Lookout Mountain. The film was accompanied by powerful, Wagner-esque music featured on many test films of that period and was hosted by actor Reed Hadley. After the test a private screening was given to President Dwight D. Eisenhower. It was later released to the public after sanitizing, and was for many days played continually on many television channels. Wilhelm Richard Wagner (Leipzig, May 22, 1813 – Venice, February 13, 1883) was an influential German composer, conductor, music theorist, and essayist, primarily known for his operas (or music dramas as he later came to call them). ... Reed Hadley (b. ... Eisenhower redirects here. ...

See also

• History of nuclear weapons
• Ivy King
• Operation Castle

A nuclear fireball lights up the night in a United States nuclear test. ... Ivy Kings mushroom cloud. ... Operation Castle was the highest-yield nuclear test series ever conducted by the United States. ...

External links

Wikimedia Commons has media related to:

Operation Ivy

• Downloadable/Streamable Declassified Film: Operation IVY (1 hour originally Secret version, 1953) at the Internet Archive
• Operation Ivy film (27 minutes unclassified civil defence version, 1953)
• Operation Ivy

Image File history File links Commons-logo. ... Wikimedia Commons logo by Reid Beels The Wikimedia Commons (also called Commons or Wikicommons) is a repository of free content images, sound and other multimedia files. ...

References

• Chuck Hansen, U. S. Nuclear Weapons: The Secret History (Arlington: AeroFax, 1988)
• Richard Rhodes, Dark Sun: The Making of the Hydrogen Bomb (New York: Simon and Schuster, 1995)