Operation Ivy

For the ska punk band, see Operation Ivy (band).

Operation Ivy
Ivy Mike
Information
Country	United States
Test site	Pacific Proving Grounds
Period	November 1952
Number of tests	2
Test type	Atmospheric tests
Device type	Thermonuclear (Mike) Fission (King)
Max. yield	10.4 Mt
Navigation
Previous test	Operation Tumbler-Snapper
Next test	Operation Upshot-Knothole

Operation Ivy was the eighth series of American nuclear tests, coming after Tumbler-Snapper and before Upshot-Knothole. Its purpose was to help upgrade the U.S. arsenal of nuclear weapons in response to the Soviet nuclear weapons program. The two explosions were staged in late 1952 at Enewetak Atoll in the Pacific Proving Ground in the Marshall Islands.

The first Ivy shot, Mike, was the first successful full-scale test of a multi-megaton thermonuclear weapon ("hydrogen bomb") using the Teller-Ulam design. Unlike later thermonuclear weapons, Mike used deuterium as its fusion fuel, maintained as a liquid by an expensive and cumbersome cryogenic system. It was detonated on Elugelab Island yielding 10.4 megatons, almost 500 times the bomb dropped on Nagasaki. 8 megatons of the yield was from fast fission of the uranium tamper, creating massive amounts of radioactive fallout. The detonation left an underwater crater 6,240 ft (1.9 km) wide and 164 ft (50 m) deep where Elugelab Island had been. Following this successful test, the Mike design was weaponized as either the EC-16 or TX-16, but it was quickly abandoned for solid-fueled designs after the success of the Castle Bravo shot.

The second test, King, fired the largest nuclear weapon to date using only nuclear fission (no fusion nor fusion boosting). This "Super Oralloy Bomb" was intended as a backup if the fusion weapon failed. King yielded 500 kilotons, 25-40 times more than the nuclear weapons dropped during World War II.

Jimmy P. Robinson,^[1] a USAF captain, was lost while piloting his F-84G through the mushroom cloud to collect air samples; he ran out of fuel and attempted to land on water but was never found.^[2]

Ivy test blasts

Test name	Date	Location	Yield	Note
Mike	1 November 1952	Elugelab Island, Eniwetok	10.4 - 12 megatons	First hydrogen bomb
King	16 November 1952	Airburst 2,000 feet North of Runit Island, Eniwetok	500 kilotons	Largest pure-fission bomb up to that time

See also

• History of nuclear weapons
• Operation Castle

References

• Chuck Hansen, U. S. Nuclear Weapons: The Secret History (Arlington: AeroFax, 1988)

1. ^ http://www.airspacemag.com/history-of-flight/Into-the-Mushroom-Cloud.html?c=y&page=3
2. ^ http://www.arlingtoncemetery.net/jprobinson.htm

External links

• Curtiss Atomic Marines
• Operation Ivy
• Analysis of Radiation Exposure for Navy Personnel at Operation Ivy
• Internet Archive: Operation Ivy (1952) — film about Operation Ivy created by the US Air Force