Editing Nuclear weapon (section)

=== Other types ===
{{Main|Boosted fission weapon|Neutron bomb|Radiological warfare|Induced gamma emission|Antimatter weapon}}
There are other types of nuclear weapons as well. For example, a [[boosted fission weapon]] is a fission bomb that increases its explosive yield through a small number of fusion reactions, but it is not a fusion bomb. In the boosted bomb, the neutrons produced by the fusion reactions serve primarily to increase the efficiency of the fission bomb. There are two types of boosted fission bomb: internally boosted, in which a deuterium-tritium mixture is injected into the bomb core, and externally boosted, in which concentric shells of lithium-deuteride and depleted uranium are layered on the outside of the fission bomb core. The external method of boosting enabled the [[USSR]] to field the first partially thermonuclear weapons, but it is now obsolete because it demands a spherical bomb geometry, which was adequate during the 1950s arms race when bomber aircraft were the only available delivery vehicles.

The detonation of any nuclear weapon is accompanied by a blast of [[neutron radiation]]. Surrounding a nuclear weapon with suitable materials (such as [[cobalt]] or [[gold]]) creates a weapon known as a [[salted bomb]]. This device can produce exceptionally large quantities of long-lived [[radioactive contamination]]. It has been conjectured that such a device could serve as a "doomsday weapon" because such a large quantity of radioactivities with half-lives of decades, lifted into the stratosphere where winds would distribute it around the globe, would make all life on the planet extinct.

In connection with the [[Strategic Defense Initiative]], research into the [[nuclear pumped laser]] was conducted under the DOD program [[Project Excalibur]] but this did not result in a working weapon. The concept involves the tapping of the energy of an exploding nuclear bomb to power a single-shot laser that is directed at a distant target.

During the [[Starfish Prime]] high-altitude nuclear test in 1962, an unexpected effect was produced which is called a [[nuclear electromagnetic pulse]]. This is an intense flash of electromagnetic energy produced by a rain of high-energy electrons which in turn are produced by a nuclear bomb's gamma rays. This flash of energy can permanently destroy or disrupt electronic equipment if insufficiently shielded. It has been proposed to use this effect to disable an enemy's military and civilian infrastructure as an adjunct to other nuclear or conventional military operations. By itself it could as well be useful to terrorists for crippling a nation's economic electronics-based infrastructure. Because the effect is most effectively produced by high altitude nuclear detonations (by military weapons delivered by air, though ground bursts also produce EMP effects over a localized area), it can produce damage to electronics over a wide, even continental, geographical area.<ref>{{Cite web |date=2021-07-15 |title=Why the U.S. once set off a nuclear bomb in space |url=https://www.nationalgeographic.com/premium/article/why-the-us-once-set-off-a-nuclear-bomb-in-space-called-starfish-prime |access-date=2023-11-27 |website=Premium |language=en |archive-date=November 29, 2023 |archive-url=https://web.archive.org/web/20231129191301/https://www.nationalgeographic.com/premium/article/why-the-us-once-set-off-a-nuclear-bomb-in-space-called-starfish-prime |url-status=live }}</ref>

Research has been done into the possibility of [[pure fusion weapon|pure fusion bombs]]: nuclear weapons that consist of fusion reactions without requiring a fission bomb to initiate them. Such a device might provide a simpler path to thermonuclear weapons than one that required the development of fission weapons first, and pure fusion weapons would create significantly less nuclear fallout than other thermonuclear weapons because they would not disperse fission products. In 1998, the [[United States Department of Energy]] divulged that the United States had, "...made a substantial investment" in the past to develop pure fusion weapons, but that, "The U.S. does not have and is not developing a pure fusion weapon", and that, "No credible design for a pure fusion weapon resulted from the DOE investment".<ref>U.S. Department of Energy, [https://fas.org/sgp/othergov/doe/rdd-8.pdf Restricted Data Declassification Decisions, 1946 to the Present (RDD-8)] {{webarchive |url=https://web.archive.org/web/20150924140708/http://www.fas.org/sgp/othergov/doe/rdd-8.pdf |date=September 24, 2015}} (January 1, 2002), accessed November 20, 2011.</ref>

[[Nuclear isomers]] provide a possible pathway to fissionless fusion bombs. These are naturally occurring [[isotopes]] ([[Isotopes of hafnium|<sup>178m2</sup>Hf]] being a prominent example) which exist in an elevated energy state. Mechanisms to release this energy as bursts of gamma radiation (as in the [[hafnium controversy]]) have been proposed as possible triggers for conventional thermonuclear reactions.

[[Antimatter]], which consists of [[particles]] resembling ordinary [[matter]] particles in most of their properties but having opposite [[electric charge]], has been considered as a trigger mechanism for nuclear weapons.<ref name="arxiv.org">{{cite arXiv|eprint=physics/0510071 |last1=Gsponer |first1=Andre |title=Fourth Generation Nuclear Weapons: Military effectiveness and collateral effects |year=2005}}</ref><ref>{{cite web |url=http://www.nextbigfuture.com/2015/09/details-on-antimatter-triggered-fusion.html|title=Details on antimatter triggered fusion bombs |website=NextBigFuture.com|date=September 22, 2015 |url-status=live |archive-url=https://web.archive.org/web/20170422125419/http://www.nextbigfuture.com/2015/09/details-on-antimatter-triggered-fusion.html|archive-date=April 22, 2017}}</ref><ref>{{cite web |url=http://cui.unige.ch/isi/sscr/phys/anti-BPP-3.html |title=Page discussing the possibility of using antimatter as a trigger for a thermonuclear explosion |publisher=Cui.unige.ch |access-date=May 30, 2013 |url-status=live |archive-url=https://web.archive.org/web/20130424174413/http://cui.unige.ch/isi/sscr/phys/anti-BPP-3.html |archive-date=April 24, 2013}}</ref> A major obstacle is the difficulty of producing antimatter in large enough quantities, and there is no evidence that it is feasible beyond the military domain.<ref>{{Cite book |arxiv=physics/0507114 |last1=Gsponer |first1=Andre |last2=Hurni |first2=Jean-Pierre |chapter=The physics of antimatter induced fusion and thermonuclear explosions |editor1-first=G. |editor1-last=Velarde |editor2-first=E. |editor2-last=Minguez |title=Proceedings of the 4th International Conference on Emerging Nuclear Energy Systems, Madrid, June 30/July 4, 1986 |publisher=World Scientific, Singapore |year=1987 |pages=166–169}}</ref> However, the US Air Force funded studies of the physics of antimatter in the [[Cold War]], and began considering its possible use in weapons, not just as a trigger, but as the explosive itself.<ref>{{cite news |author1=Keay Davidson |author2=Chronicle Science Writer |url=http://sfgate.com/cgi-bin/article.cgi?file=/c/a/2004/10/04/MNGM393GPK1.DTL |title=Air Force pursuing antimatter weapons: Program was touted publicly, then came official gag order |publisher=Sfgate.com |date=October 4, 2004 |access-date=May 30, 2013 |url-status=live |archive-url=https://web.archive.org/web/20120609101650/http://www.sfgate.com/cgi-bin/article.cgi?file=%2Fc%2Fa%2F2004%2F10%2F04%2FMNGM393GPK1.DTL |archive-date=June 9, 2012}}</ref> A fourth generation nuclear weapon design<ref name="arxiv.org" /> is related to, and relies upon, the same principle as [[antimatter-catalyzed nuclear pulse propulsion]].<ref>{{cite web |url=http://nuclearweaponarchive.org/News/INESAPTR1.html|title=Fourth Generation Nuclear Weapons|access-date=October 24, 2014 |url-status=live |archive-url=https://web.archive.org/web/20160323010905/http://nuclearweaponarchive.org/News/INESAPTR1.html|archive-date=March 23, 2016}}</ref>

Most variation in [[nuclear weapon design]] is for the purpose of achieving [[Dial-a-yield|different yields for different situations]], and in manipulating design elements to attempt to minimize weapon size,<ref name="Hansen" /> [[Nuclear fratricide|radiation hardness]] or requirements for special materials, especially fissile fuel or tritium.

====Tactical nuclear weapons====
[[File:ChemicalExercise2018-01.jpg|thumb|right|Soviet [[OTR-21 Tochka]] missile. Capable of firing a 100-kiloton nuclear warhead a distance of 185 km]]
Some nuclear weapons are designed for special purposes; most of these are for non-strategic (decisively war-winning) purposes and are referred to as [[tactical nuclear weapon]]s.

The [[neutron bomb]] purportedly conceived by [[Samuel T. Cohen|Sam Cohen]] is a thermonuclear weapon that yields a relatively small explosion but a relatively large amount of neutron [[radiation]]. Such a weapon could, according to tacticians, be used to cause massive biological casualties while leaving inanimate infrastructure mostly intact and creating minimal fallout. Because high energy neutrons are capable of penetrating dense matter, such as tank armor, neutron warheads were procured in the 1980s (though not deployed in Europe) for use as tactical payloads for US Army artillery shells (200&nbsp;mm [[W79 Artillery-Fired Atomic Projectile|W79]] and 155&nbsp;mm [[W82]]) and [[MGM-52 Lance|short range missile]] forces. Soviet authorities announced similar intentions for neutron warhead deployment in Europe; indeed, they claimed to have originally invented the neutron bomb, but their deployment on USSR tactical nuclear forces is unverifiable.{{citation needed|date=May 2022}}

A type of nuclear explosive most suitable for use by ground special forces was the [[Special Atomic Demolition Munition]], or SADM, sometimes popularly known as a [[Suitcase nuclear device|suitcase nuke]]. This is a nuclear bomb that is man-portable, or at least truck-portable, and though of a relatively small yield (one or two kilotons) is sufficient to destroy important tactical targets such as bridges, dams, tunnels, important military or commercial installations, etc. either behind enemy lines or pre-emptively on friendly territory soon to be overtaken by invading enemy forces. These weapons require plutonium fuel and are particularly "dirty". They also demand especially stringent security precautions in their storage and deployment.{{citation needed|date=May 2022}}

Small "tactical" nuclear weapons were deployed for use as antiaircraft weapons. Examples include the USAF [[AIR-2 Genie]], the [[AIM-26 Falcon]] and US Army [[Nike Hercules]]. Missile interceptors such as the [[Sprint (missile)|Sprint]] and the [[LIM-49 Spartan|Spartan]] also used small nuclear warheads (optimized to produce neutron or X-ray flux) but were for use against enemy strategic warheads.{{citation needed|date=May 2022}}

Other small, or tactical, nuclear weapons were deployed by naval forces for use primarily as [[antisubmarine]] weapons. These included nuclear [[depth charge|depth bombs]] or nuclear armed torpedoes. Nuclear mines for use on land or at sea are also possibilities.{{citation needed|date=May 2022}}