A neutron bomb, officially defined as a type of enhanced radiation weapon (ERW), is a low-yield thermonuclear weapon designed to maximize lethal neutron radiation in the immediate vicinity of the blast while minimizing the physical power of the blast itself. The neutron release generated by a nuclear fusion reaction is intentionally allowed to escape the weapon, rather than being absorbed by its other components. The neutron burst, which is used as the primary destructive action of the warhead, is able to penetrate enemy armor more effectively than a conventional warhead, thus making it more lethal as a tactical weapon.
Nuclear weapons design are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types:
- Pure fission weapons are the simplest, least technically demanding, were the first nuclear weapons built, and so far the only type ever used in warfare, by the United States on Japan in World War II.
- Boosted fission weapons increase yield beyond that of the implosion design, by using small quantities of fusion fuel to enhance the fission chain reaction. Boosting can more than double the weapon's fission energy yield.
- Staged thermonuclear weapons are arrangements of two or more "stages", most usually two. The first stage is normally a boosted fission weapon as above. Its detonation causes it to shine intensely with X-rays, which illuminate and implode the second stage filled with a large quantity of fusion fuel. This sets in motion a sequence of events which results in a thermonuclear, or fusion, burn. This process affords potential yields up to hundreds of times those of fission weapons.
Yellow Sun was the first British operational high-yield strategic nuclear weapon warhead. The name refers only to the outer casing; the warhead was known as "Green Grass" in Yellow Sun Mk.1 and "Red Snow" in Yellow Sun Mk.2.
The B61 nuclear bomb is the primary thermonuclear gravity bomb in the United States Enduring Stockpile following the end of the Cold War. It is a low-to-intermediate yield strategic and tactical nuclear weapon featuring a two-stage radiation implosion design.
The W85 was a thermonuclear warhead developed by the United States to arm the Pershing II missile. It was a variable yield device with a selectable yield of 0.3, 5, 10 or 80 kilotonnes of TNT.
Mark 7 "Thor" was the first tactical fission bomb adopted by US armed forces. It was also the first weapon to be delivered via toss bombing with the help of the low-altitude bombing system (LABS). The weapon was tested in Operation Buster-Jangle. The Mark 7 was fitted with retractable stabilizer fins so it could be carried under fighter-bomber aircraft. The Mark 7 warhead (W7) also formed the basis of the 30.5 inches (775 mm) BOAR rocket, the Mark 90 Betty nuclear depth charge, MGR-1 Honest John rocket, MGM-5 Corporal ballistic missile, and Nike Ajax surface-to-air missile. It was also supplied for delivery by Royal Air Force Canberra aircraft assigned to NATO in Germany under the command of SACEUR. This was done under the auspices of Project E, an agreement between the United States and the UK on the RAF carriage of US nuclear weapons. In UK use it was designated 1,650 lb. H.E. M.C. The Mark 7 was in service from 1952 to 1967(8) with 1,700–1,800 having been built.
The W87 is an American thermonuclear missile warhead formerly deployed on the LGM-118A Peacekeeper ("MX") ICBM. 50 MX missiles were built, each carrying up to 10 W87 warheads in multiple independently targetable reentry vehicles (MIRV), and were deployed from 1986 to 2005. Starting in 2007, 250 of the W87 warheads from retired Peacekeeper missiles were retrofitted onto much older Minuteman III missiles, with one warhead per missile. An upgraded version is planned for use on the forthcoming LGM-35A Sentinel ICBM.
The W84 is an American thermonuclear warhead initially designed for use on the BGM-109G Gryphon Ground Launched Cruise Missile (GLCM).
The B46 nuclear bomb was an American high-yield thermonuclear bomb which was designed and tested in the late 1950s. It was never deployed. Though originally intended to be a production design, the B46 ended up being only an intermediate prototype of the B-53 and was test fired several times. These prototypes were known as TX-46 units (Test/Experimental).
The Mark 5 nuclear bomb and W5 nuclear warhead were a common core American nuclear weapon design, designed in the early 1950s and which saw service from 1952 to 1963.
The Mark 4 nuclear bomb was an American implosion-type nuclear bomb based on the earlier Mark 3 Fat Man design, used in the Trinity test and the bombing of Nagasaki. With the Mark 3 needing each individual component to be hand-assembled by only highly trained technicians under closely controlled conditions, the purpose of the Mark 4 was to produce an atomic weapon as a practical piece of ordnance. The Mark 4 Mod 0 entered the stockpile starting March 19, 1949 and was in use until 1953. With over 500 units procured, the Mark 4 was the first mass-produced nuclear weapon.
The Mark 39 nuclear bomb and W39 nuclear warhead were versions of an American thermonuclear weapon, which were in service from 1957 to 1966.
The Mark 18 nuclear bomb, also known as the SOB or Super Oralloy Bomb, was an American nuclear bomb design which was the highest yield fission bomb produced by the US. The Mark 18 had a design yield of 500 kilotons. Nuclear weapon designer Ted Taylor was the lead designer for the Mark 18.
The Mark 8 nuclear bomb was an American nuclear bomb, designed in the late 1940s and early 1950s, which was in service from 1952 to 1957.
The W30 was an American nuclear warhead used on the RIM-8 Talos surface-to-air missile and the Tactical Atomic Demolition Munition (TADM).
The Mark 24 nuclear bomb was an American thermonuclear bomb design, based on the third American thermonuclear bomb test, Castle Yankee. The Mark 24 bomb was tied as the largest weight and size nuclear bomb ever deployed by the United States, with the same size and weight as the Mark 17 nuclear bomb which used a very similar design concept but unenriched lithium.
A strategic nuclear weapon (SNW) is a nuclear weapon that is designed to be used on targets often in settled territory far from the battlefield as part of a strategic plan, such as military bases, military command centers, arms industries, transportation, economic, and energy infrastructure, and countervalue targets such areas such as cities and towns. It is in contrast to a tactical nuclear weapon, which is designed for use in battle as part of an attack with and often near friendly conventional forces, possibly on contested friendly territory. As of 2024, strategic nuclear weapons have been used twice in the 1945 United States bombings of Hiroshima and Nagasaki.
The Mark 13 nuclear bomb and its variant, the W-13 nuclear warhead for Redstone BM and Snark CM, were experimental nuclear weapons developed by the United States from 1951 to 1954. The Mark 13 design was based on the earlier Mark 6 nuclear bomb design, which was in turn based on the Mark 4 nuclear bomb and the Mark 3 nuclear bomb used at the end of World War II.
In nuclear weapon design, the pit is the core of an implosion nuclear weapon, consisting of fissile material and any neutron reflector or tamper bonded to it. Some weapons tested during the 1950s used pits made with uranium-235 alone, or as a composite with plutonium. All-plutonium pits are the smallest in diameter and have been the standard since the early 1960s. The pit is named after the hard core found in stonefruit such as peaches and apricots.
