History of the Teller–Ulam design in the context of "Radiation implosion"

A thermonuclear weapon, fusion weapon or hydrogen bomb (H-bomb) is a second-generation nuclear weapon, utilizing nuclear fusion. The most destructive weapons ever created, their yields typically exceed first-generation nuclear weapons by twenty times, with far lower mass and volume requirements. Characteristics of fusion reactions can make possible the use of non-fissile depleted uranium as the weapon's main fuel, thus allowing more efficient use of scarce fissile material. Its multi-stage design is distinct from the usage of fusion in simpler boosted fission weapons. The first full-scale thermonuclear test (Ivy Mike) was carried out by the United States in 1952, and the concept has since been employed by at least the five NPT-recognized nuclear-weapon states: the United States, Russia, the United Kingdom, China, and France.

The design of all thermonuclear weapons is believed to be the Teller–Ulam configuration. This relies on radiation implosion, in which X-rays from detonation of the primary stage, a fission bomb, are channelled to compress a separate fusion secondary stage containing thermonuclear fuel, primarily lithium-6 deuteride. During detonation, neutrons convert lithium-6 to helium-4 plus tritium. The heavy isotopes of hydrogen, deuterium and tritium, then undergo a reaction that releases energy and neutrons. For this reason, thermonuclear weapons are often colloquially called hydrogen bombs or H-bombs.

Stanisław Marcin Ulam (Polish: [sta'ɲiswaf 'mart͡ɕin 'ulam]; 13 April 1909 – 13 May 1984) was a Polish and American mathematician, nuclear physicist and computer scientist. He participated in the Manhattan Project, originated the Teller–Ulam design of thermonuclear weapons, discovered the concept of the cellular automaton, invented the Monte Carlo method of computation, and suggested nuclear pulse propulsion. In pure and applied mathematics, he proved a number of theorems and proposed several conjectures.

Born into a wealthy Polish Jewish family in Lemberg, Austria-Hungary, Ulam studied mathematics at the Lwów Polytechnic Institute, where he earned his PhD in 1933 under the supervision of Kazimierz Kuratowski and Włodzimierz Stożek. In 1935, John von Neumann, whom Ulam had met in Warsaw, invited him to come to the Institute for Advanced Study in Princeton, New Jersey, for a few months. From 1936 to 1939, he spent summers in Poland and academic years at Harvard University in Cambridge, Massachusetts, where he worked to establish important results regarding ergodic theory. On 20 August 1939, he sailed for the United States for the last time with his 17-year-old brother Adam Ulam. He became an assistant professor at the University of Wisconsin–Madison in 1940, and a United States citizen in 1941.

Edward Teller (Hungarian: Teller Ede; January 15, 1908 – September 9, 2003) was a Hungarian-American theoretical physicist and chemical engineer who is known colloquially as "the father of the hydrogen bomb" and one of the creators of the Teller–Ulam design inspired by Stanisław Ulam. He had a volatile personality, and was "driven by his megaton ambitions, had a messianic complex, and displayed autocratic behavior." He devised a thermonuclear Alarm Clock bomb with a yield of 1000 MT (1 GT of TNT) and proposed delivering it by boat or submarine to incinerate a continent.

Born in Austria-Hungary in 1908, Teller emigrated to the US in the 1930s, one of the many so-called "Martians", a group of Hungarian scientist émigrés. He made numerous contributions to nuclear and molecular physics, spectroscopy, and surface physics. His extension of Enrico Fermi's theory of beta decay, in the form of Gamow–Teller transitions, provided an important stepping stone in its application, while the Jahn–Teller effect and Brunauer–Emmett–Teller (BET) theory have retained their original formulation and are mainstays in physics and chemistry. Teller analyzed his problems using basic principles of physics and often discussed with his cohorts to make headway through difficult problems. This was seen when he worked with Stanislaw Ulam to get a workable thermonuclear fusion bomb design, but later temperamentally dismissed Ulam's aid. Herbert York stated that Teller utilized Ulam's general idea of compressive heating to start thermonuclear fusion to generate his own sketch of a workable "Super" bomb. Before Ulam's idea, Teller's classical Super was essentially a system for heating uncompressed liquid deuterium to the point, Teller hoped, that it would sustain thermonuclear burning. It was, in essence, a simple idea from physical principles, which Teller pursued with a ferocious tenacity, even if he was wrong and shown that it would not work. To get support from Washington for his Super weapon project, Teller proposed a thermonuclear radiation implosion experiment as the "George" shot of Operation Greenhouse.