Operation Ivy
Encyclopedia
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 weapon
s 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, 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.
Nuclear testing
Nuclear weapons tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapons. Throughout the twentieth century, most nations that have developed nuclear weapons have tested them...
, coming after Tumbler-Snapper
Operation Tumbler-Snapper
Operation Tumbler-Snapper was a series of atomic tests conducted by the United States in early 1952 at the Nevada Test Site. The Tumbler-Snapper Series of tests followed Operation Buster-Jangle, and preceded Operation Ivy....
and before Upshot-Knothole
Operation Upshot-Knothole
Operation Upshot-Knothole was a series of eleven nuclear test shots conducted in 1953 at the Nevada Test Site.Over twenty-one thousand soldiers took part in the ground exercise Desert Rock V in conjunction with the Grable shot...
. Its purpose was to help upgrade the U.S. arsenal of nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
s 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
Marshall Islands
The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...
.
The first Ivy shot, Mike
Ivy Mike
Ivy Mike was the codename given to the first United States test of a thermonuclear weapon, in which a major part of the explosive yield came from nuclear fusion. It was detonated on November 1, 1952 by the United States at on Enewetak, an atoll in the Pacific Ocean, as part of Operation Ivy...
, was the first successful full-scale test of a multi-megaton thermonuclear weapon ("hydrogen bomb") using the Teller-Ulam design
Teller-Ulam design
The Teller–Ulam design is the nuclear weapon design concept used in most of the world's nuclear weapons. It is colloquially referred to as "the secret of the hydrogen bomb" because it employs hydrogen fusion, though in most applications the bulk of its destructive energy comes from uranium fission,...
. Unlike later thermonuclear weapons, Mike used deuterium
Deuterium
Deuterium, also called heavy hydrogen, is one of two stable isotopes of hydrogen. It has a natural abundance in Earth's oceans of about one atom in of hydrogen . Deuterium accounts for approximately 0.0156% of all naturally occurring hydrogen in Earth's oceans, while the most common isotope ...
as its fusion fuel, maintained as a liquid by an expensive and cumbersome cryogenic system. It was detonated on Elugelab Island
Elugelab
Elugelab was an island, part of the Enewetak atoll in the Marshall Islands. It was destroyed by the world's first test of a hydrogen bomb on 1 November 1952, as part of Operation Ivy...
yielding 10.4 megatons
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...
, 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
Mark 16 nuclear bomb
The Mark 16 nuclear bomb was a large thermonuclear bomb, based on the design of the Ivy Mike, the first hydrogen bomb test fired. The Mark 16 is more properly designated TX-16/EC-16 as it only existed in Experimental/Emergency Capability versions....
, but it was quickly abandoned for solid-fueled designs after the success of the Castle Bravo
Castle Bravo
Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb device, detonated on March 1, 1954 at Bikini Atoll, Marshall Islands, as the first test of Operation Castle. Castle Bravo was the most powerful nuclear device ever detonated by the United States ,...
shot.
The second test, King
Ivy King
Ivy King was the largest pure fission nuclear bomb ever tested by the United States. The bomb was tested during the Truman administration as part of Operation Ivy...
, fired the largest nuclear weapon to date using only nuclear fission
Nuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...
(no fusion nor fusion boosting
Boosted fission weapon
A boosted fission weapon usually refers to a type of nuclear bomb that uses a small amount of fusion fuel to increase the rate, and thus yield, of a fission reaction. The neutrons released by the fusion reactions add to the neutrons released in the fission, as well as inducing the fission reactions...
). This "Super Oralloy
Enriched uranium
Enriched uranium is a kind of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its weight...
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
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
Jimmy P. Robinson, a USAF captain, was lost while piloting his F-84G
F-84 Thunderjet
The Republic F-84 Thunderjet was an American turbojet fighter-bomber aircraft. Originating as a 1944 United States Army Air Forces proposal for a "day fighter", the F-84 flew in 1946...
through the mushroom cloud to collect air samples; he ran out of fuel and attempted to land on water but was never found.
| Test name | Date | Location | Yield | Note |
|---|---|---|---|---|
| Mike Ivy Mike Ivy Mike was the codename given to the first United States test of a thermonuclear weapon, in which a major part of the explosive yield came from nuclear fusion. It was detonated on November 1, 1952 by the United States at on Enewetak, an atoll in the Pacific Ocean, as part of Operation Ivy... |
1 November 1952 | Elugelab Island, Eniwetok | 10.4 - 12 megatons | First hydrogen bomb |
| King Ivy King Ivy King was the largest pure fission nuclear bomb ever tested by the United States. The bomb was tested during the Truman administration as part of Operation Ivy... |
16 November 1952 | Airburst 2,000 feet North of Runit Island, Eniwetok | 500 kilotons | Largest pure-fission bomb up to that time |
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