"Fat Man" was the codename for the type of nuclear bomb the United States detonated over the Japanese city of Nagasaki on 9 August 1945. It was the second of the only two nuclear weapons ever used in warfare, the first being Little Boy, and its detonation marked the third nuclear explosion in history. It was built by scientists and engineers at Los Alamos Laboratory using plutonium from the Hanford Site, and was dropped from the Boeing B-29 Superfortress Bockscar piloted by Major Charles Sweeney.
Edward Teller was a Hungarian-American theoretical physicist who is known colloquially as "the father of the hydrogen bomb", although he did not care for the title, considering it to be in poor taste. Throughout his life, Teller was known both for his scientific ability and for his difficult interpersonal relations and volatile personality.
Lawrence Livermore National Laboratory (LLNL) is a federally funded research and development center in Livermore, California, United States. Originally established in 1952, the laboratory now is sponsored by the United States Department of Energy and administrated by Lawrence Livermore National Security, LLC.
Inertial confinement fusion (ICF) is a fusion energy process that initiates nuclear fusion reactions by compressing and heating targets filled with fuel. The targets are small pellets, typically containing deuterium (2H) and tritium (3H).
Edwin Mattison McMillan was an American physicist credited with being the first-ever to produce a transuranium element, neptunium. For this, he shared the 1951 Nobel Prize in Chemistry with Glenn Seaborg.
Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types:
Project Plowshare was the overall United States program for the development of techniques to use nuclear explosives for peaceful construction purposes. The program was organized in June 1957 as part of the worldwide Atoms for Peace efforts. As part of the program, 35 nuclear warheads were detonated in 27 separate tests. A similar program was carried out in the Soviet Union under the name Nuclear Explosions for the National Economy.
Polymer-bonded explosives, also called PBX or plastic-bonded explosives, are explosive materials in which explosive powder is bound together in a matrix using small quantities of a synthetic polymer. PBXs are normally used for explosive materials that are not easily melted into a casting, or are otherwise difficult to form.
Project Orion was a study conducted between the 1950s and 1960s by the United States Air Force, DARPA, and NASA for the purpose of measuring the efficacy of a starship directly propelled by a series of explosions of atomic bombs behind the craft—nuclear pulse propulsion. Early versions of this vehicle were proposed to take off from the ground; later versions were presented for use only in space. Six non-nuclear tests were conducted using models. The project was eventually abandoned for multiple reasons, including the Partial Test Ban Treaty, which banned nuclear explosions in space, and concerns over nuclear fallout.
The National Ignition Facility (NIF) is a laser-based inertial confinement fusion (ICF) research device, located at Lawrence Livermore National Laboratory in Livermore, California, United States. NIF's mission is to achieve fusion ignition with high energy gain. It achieved the first scientific breakeven controlled fusion experiment on December 5, 2022, with an energy gain factor of 1.5. It supports nuclear weapon maintenance and design by studying the behavior of matter under the conditions found within nuclear explosions.
The Soviet atomic bomb project was the classified research and development program that was authorized by Joseph Stalin in the Soviet Union to develop nuclear weapons during and after World War II.
RDS-37 was the Soviet Union's first two-stage hydrogen bomb, first tested on 22 November 1955. The weapon had a nominal yield of approximately 3 megatons. It was scaled down to 1.6 megatons for the live test.
A thermonuclear weapon, fusion weapon or hydrogen bomb is a second-generation nuclear weapon design. Its greater sophistication affords it vastly greater destructive power than first-generation nuclear bombs, a more compact size, a lower mass, or a combination of these benefits. Characteristics of nuclear fusion reactions make possible the use of non-fissile depleted uranium as the weapon's main fuel, thus allowing more efficient use of scarce fissile material such as uranium-235 or plutonium-239. The first full-scale thermonuclear test was carried out by the United States in 1952; the concept has since been employed by most of the world's nuclear powers in the design of their weapons.
This article chronicles the history and origins of the Teller–Ulam design, the technical concept behind modern thermonuclear weapons, also known as hydrogen bombs. The design - the details of which are military secrets known to only a handful of major nations - is believed to be used in virtually all modern nuclear weapons that make up the arsenals of the major nuclear powers.
Peaceful nuclear explosions (PNEs) are nuclear explosions conducted for non-military purposes. Proposed uses include excavation for the building of canals and harbours, electrical generation, the use of nuclear explosions to drive spacecraft, and as a form of wide-area fracking. PNEs were an area of some research from the late 1950s into the 1980s, primarily in the United States and Soviet Union.
The W71 nuclear warhead was a US thermonuclear warhead developed at Lawrence Livermore National Laboratory in California and deployed on the LIM-49A Spartan missile, a component of the Safeguard Program, an anti-ballistic missile (ABM) defense system briefly deployed by the US in the 1970s.
The Los Alamos Primer was a printed version of the first five lectures on the principles of nuclear weapons given to new arrivals at the top-secret Los Alamos laboratory during the Manhattan Project. They were originally given by the physicist Robert Serber after being delivered in person on April 5–14, 1943, based on conclusions reached at a conference held in July and September 1942 at the University of California, Berkeley by Robert Oppenheimer. The notes from the lecture which became the Primer were written by Edward Condon.
"Thin Man" was the code name for a proposed plutonium gun-type nuclear bomb that the United States was developing during the Manhattan Project. Its development was abandoned when it was discovered that the spontaneous fission rate of nuclear reactor-bred plutonium was too high for use in a gun-type design due to the high concentration of the isotope plutonium-240.
The uranium hydride bomb was a variant design of the atomic bomb first suggested by Robert Oppenheimer in 1939 and advocated and tested by Edward Teller. It used deuterium, an isotope of hydrogen, as a neutron moderator in a uranium-deuterium ceramic compact. Unlike all other fission-based weapon types, the concept relies on a chain reaction of slow nuclear fission. Bomb efficiency was adversely affected by the cooling of neutrons since the latter delays the reaction, as delineated by Rob Serber in his 1992 extension of the original Los Alamos Primer.
The Los Alamos Laboratory, also known as Project Y, was a secret laboratory established by the Manhattan Project and operated by the University of California during World War II. Its mission was to design and build the first atomic bombs. Robert Oppenheimer was its first director, serving from 1943 to December 1945, when he was succeeded by Norris Bradbury. In order to enable scientists to freely discuss their work while preserving security, the laboratory was located in a remote part of New Mexico. The wartime laboratory occupied buildings that had once been part of the Los Alamos Ranch School.
