Hydrogen bomb
A hydrogen bomb, also known as a thermonuclear bomb, is a type of explosive device that uses nuclear fusion to release energy. The process typically involves a fission bomb that initiates a reaction in a fusion material, such as liquid deuterium, leading to a significantly more powerful explosion than that of atomic bombs. The development of the hydrogen bomb became a priority for the United States after the Soviet Union successfully tested its atomic bomb in 1949, heightening the arms race during the Cold War. The first successful test of a hydrogen bomb, code-named Ivy Mike, occurred on November 1, 1952, resulting in a massive yield and leaving a large underwater crater. The Soviet Union followed suit, testing its own version in 1953. As the nuclear arms race intensified, both nations engaged in the development and testing of increasingly powerful weapons, which led to public fear and civil defense measures in the United States. Despite the potential for catastrophic destruction, leaders of nuclear powers have historically sought diplomatic resolutions to conflicts, maintaining a precarious balance of deterrence known as "the balance of terror." The legacy of hydrogen bomb development continues to influence global politics and discussions surrounding nuclear weapons today.
Hydrogen bomb
Powerful nuclear weapon that generates a large portion of its explosive power through nuclear fusion
Date First tested on March 1, 1954
Development of the hydrogen bomb raised the stakes in the nuclear weapons arm race, magnified tensions in the Cold War, and intensified public fear of thermonuclear war.
J. Robert Oppenheimer led the development of the atomic bomb, but he thought that creating a hydrogen bomb was both unlikely and unnecessary. His stance put him at odds with Edward Teller , who had pushed for the “super,” a fusion bomb, since 1942. The “super” was given priority only after the Soviets tested their atomic bomb in 1949, because it was seen as a way to maintain American dominance of nuclear weapons and thereby limit Soviet adventurism.
The “super” championed by Teller would use a fission bomb to establish a detonation wave in liquid deuterium, a heavy isotope of hydrogen. Deuterium nuclei were expected to fuse into helium-3 nuclei or into tritium nuclei (the heaviest hydrogen isotope), and to release a huge amount of energy in the process. Polish mathematician Stanislaw Ulam completed a complex calculation in 1950 showing that the “super” could not be made to work, but he suggested an alternative two-stage device.
Bomb Design and Testing
In the basic Ulam-Teller design, a fission bomb (the primary stage) is placed inside a heavy-walled, cylindrical tank, and a fusion package (the secondary stage) is placed beside it and aligned with the axis of the tank. The fusion package consists of three concentric cylinders: an outer jacket, a fusion fuel layer, and a uranium-235 or plutonium-239 core, called the “spark-plug.”
Code named Ivy Mike, a Teller-Ulam configuration was tested for the first time on November 1, 1952. The fusion fuel was liquid deuterium, which must be kept below 23.57 Kelvins. The 10.4-megaton explosive yield was about twice the expected yield, and it obliterated Elugelab Island of the Eniwetok Atoll in the South Pacific. In place of Elugelab, Ivy Mike left an underwater crater more than a mile wide and fifty yards deep. This ungainly design using liquid deuterium was weaponized and briefly placed in the stockpile.
The Soviet Union tested its own hydrogen bomb, Joe-4, on August 12, 1953. It was built of layers of fission and fusion fuel and had a 400-kiloton yield. The increasing pace of the arms race was evident when one considers that the Soviets were four years behind the Americans in testing an atomic bomb but only one year behind in testing a hydrogen bomb.
The first American test using lithium-deuteride was code named Castle Bravo and came on March 1, 1954. The design proved to be far more efficient than expected. The expected yield was 6 megatons, but the actual yield of 15 megatons made it the largest weapon ever tested by the Americans (the Soviet Union later tested a 50-megaton bomb). The wind changed shortly before the test, and the event should have been postponed; dangerous amounts of wind-borne radioactive dust fell on Marshallese Islanders and on the twenty-three crewmen of the fishing boat Fifth Lucky Dragon. One member of the boat’s crew later died from complications brought on by the radiation exposure. Testing nuclear weapons in the open atmosphere continued until the United States and the Soviet Union signed the Limited Test Ban Treaty in 1963, although a few other nations engaged in atmospheric testing after that time.
Impact
When the Soviets deployed a long-range bomber capable of reaching the United States in 1955, American civil defense measures were pushed. Basements of public buildings were designated as fallout shelters and stocked with survival rations and Geiger counters. Schoolchildren were taught to “duck” under their desks and “cover” their necks with their hands if they saw the super-bright flash of a nuclear bomb. Near ground zero, this protective reaction would accomplish nothing, but far enough away from ground zero, it might reduce injuries.
After the Soviets obtained the bomb, the United States announced the doctrine of “massive retaliation” to deter the Soviets from using their bombs on American interests. Both nations engaged in an accelerating arms race of weapons and delivery capabilities in order to be able to bomb the other nation into oblivion. While most knew it would be insane to unleash the nuclear apocalypse, deterrence during this decade rested on the assumption that the other side was prepared to do exactly that, resulting in a global climate known as “the balance of terror.” Ultimately, in spite of several threats to use nuclear weapons, the leaders of nuclear powers have always found other ways to resolve crises.
Bibliography
Ehrlich, Robert. Waging Nuclear Peace: The Technology and Politics of Nuclear Weapons. Albany: State University of New York Press, 1985. An excellent account of nuclear weapons and the arms race.
Herken, Gregg. Brotherhood of the Bomb: The Tangled Lives and Loyalties of Robert Oppenheimer, Ernest Lawrence, and Edward Teller. New York: Henry Holt, 2002. A compelling and authoritative account of three main characters in the development of nuclear weapons.
Morland, Howard. The Secret That Exploded. New York: Random House, 1981. An intriguing account of a reporter searching unclassified sources for the details of the design of the hydrogen bomb.
Rhodes, Richard. Dark Sun: The Making of the Hydrogen Bomb. New York: Simon & Schuster, 1995. An excellent popular-level treatment.