140-588: 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 B61 is of the variable yield ("dial-a-yield" in informal military jargon) design with a yield of 0.3 to 340 kilotons in its various mods ("modifications"). It
280-513: A misnomer , as their energy comes from the nucleus of the atom, just as it does with fusion weapons. In fission weapons, a mass of fissile material ( enriched uranium or plutonium ) is forced into supercriticality —allowing an exponential growth of nuclear chain reactions —either by shooting one piece of sub-critical material into another (the "gun" method) or by compression of a sub-critical sphere or cylinder of fissile material using chemically fueled explosive lenses . The latter approach,
420-665: A policy of deliberate ambiguity , it does not acknowledge having them. Germany , Italy , Turkey , Belgium , the Netherlands , and Belarus are nuclear weapons sharing states. South Africa is the only country to have independently developed and then renounced and dismantled its nuclear weapons. The Treaty on the Non-Proliferation of Nuclear Weapons aims to reduce the spread of nuclear weapons, but there are different views of its effectiveness. There are two basic types of nuclear weapons: those that derive
560-554: A "direct hole". The Russian continuity of government facility at Kosvinsky Mountain , finished in early 1996, was designed to resist US earth-penetrating warheads and serves a similar role as the American Cheyenne Mountain Complex . The timing of the Kosvinsky completion date is regarded as one explanation for US interest in a new nuclear bunker buster and the declaration of the deployment of
700-696: A conference—called for in the manifesto—in Pugwash, Nova Scotia , Eaton's birthplace. This conference was to be the first of the Pugwash Conferences on Science and World Affairs , held in July 1957. By the 1960s, steps were taken to limit both the proliferation of nuclear weapons to other countries and the environmental effects of nuclear testing . The Partial Nuclear Test Ban Treaty (1963) restricted all nuclear testing to underground nuclear testing , to prevent contamination from nuclear fallout, whereas
840-458: A faster and less vulnerable attack, the development of long-range intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs) has given some nations the ability to plausibly deliver missiles anywhere on the globe with a high likelihood of success. More advanced systems, such as multiple independently targetable reentry vehicles (MIRVs), can launch multiple warheads at different targets from one missile, reducing
980-614: A few nations possess such weapons or are suspected of seeking them. The only countries known to have detonated nuclear weapons—and acknowledge possessing them—are (chronologically by date of first test) the United States , the Soviet Union (succeeded as a nuclear power by Russia ), the United Kingdom , France , China , India , Pakistan , and North Korea . Israel is believed to possess nuclear weapons, though, in
1120-555: 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
1260-487: A full yield test of the weapon with other tests conducted between 1963 and 1968 at the Nevada Test Site. During testing, spin motors were added to the weapon to produce a spin of 5 revolutions per second. This was to improve stability and decoupling during high speed delivery. Three alternatives to the weapon were also explored for still-classified reasons. The first alternative was halted due to its similarity to
1400-421: A fusion weapon as of January 2016 , though this claim is disputed. Thermonuclear weapons are considered much more difficult to successfully design and execute than primitive fission weapons. Almost all of the nuclear weapons deployed today use the thermonuclear design because it results in an explosion hundreds of times stronger than that of a fission bomb of similar weight. Thermonuclear bombs work by using
1540-470: A ground burst to create a crater and destroy it through the shockwave. A 50-kiloton yield detonating on the ground produces a crater with a radius of 30–68 meters, depending on the density of the surface, effectively putting the bunker within the circular error probability . In 2014 critics said that a more accurate and less destructive nuclear weapon would make leaders less cautious about deploying it, while Schwartz said it would deter adversaries more because
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#17327832972641680-408: A lightweight bomb to replace existing weapons, but that both services had considerably different military requirements for such a weapon. However, the authors of the report believed that due to advances in technology it was possible for a single weapon to fulfill both requirements. This was followed by a report from Sandia in mid-1962, that believed that a lightweight nuclear bomb with full fuzing option
1820-472: 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. Research has been done into the possibility of pure fusion bombs : nuclear weapons that consist of fusion reactions without requiring
1960-643: A new gravity bomb similar to that of the B61-12, but having a high yield similar to that of the B61-7, named the B61 Mod 13. This discards plans for the Mod 13 to be a future Mod 12 LEP. It is planned that for each B61-13 produced, one fewer B61-12 is to be produced, therefore not increasing the planned number of new B61 bombs; defense officials indicated only "a few dozen" B61-13s may be produced. The new bomb will be carried by
2100-537: A new nuclear strategy, one that is distinct from that which gave relative stability during the Cold War. Since 1996, the United States has had a policy of allowing the targeting of its nuclear weapons at terrorists armed with weapons of mass destruction . Robert Gallucci argues that although traditional deterrence is not an effective approach toward terrorist groups bent on causing a nuclear catastrophe, Gallucci believes that "the United States should instead consider
2240-492: A nuclear penetrator (the "Robust Nuclear Earth Penetrator", or "RNEP") was never built, the U.S. DOE was allotted budget to develop it, and tests were conducted by the U.S. Air Force Research Laboratory . The RNEP was to use the 1.2 megaton B83 physics package. The Bush administration removed its request for funding of the weapon in October 2005. Additionally, then U.S. Senator Pete Domenici announced funding for
2380-425: A nuclear war between two nations would result in mutual annihilation. From this point of view, the significance of nuclear weapons is to deter war because any nuclear war would escalate out of mutual distrust and fear, resulting in mutually assured destruction . This threat of national, if not global, destruction has been a strong motivation for anti-nuclear weapons activism. Critics from the peace movement and within
2520-411: A nuclear weapon from another country by threatening nuclear retaliation is known as the strategy of nuclear deterrence . The goal in deterrence is to always maintain a second strike capability (the ability of a country to respond to a nuclear attack with one of its own) and potentially to strive for first strike status (the ability to destroy an enemy's nuclear forces before they could retaliate). During
2660-465: A nuclear weapon is a gravity bomb dropped from aircraft ; this was the method used by the United States against Japan in 1945. This method places few restrictions on the size of the weapon. It does, however, limit attack range, response time to an impending attack, and the number of weapons that a country can field at the same time. With miniaturization, nuclear bombs can be delivered by both strategic bombers and tactical fighter-bombers . This method
2800-409: A nuclear weapon to its target is an important factor affecting both nuclear weapon design and nuclear strategy . The design, development, and maintenance of delivery systems are among the most expensive parts of a nuclear weapons program; they account, for example, for 57% of the financial resources spent by the United States on nuclear weapons projects since 1940. The simplest method for delivering
2940-433: 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
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#17327832972643080-422: A penetrator may actually travel further through soil, its effect may be lessened due to its inability to transmit shock to the target. Further thinking on the subject envisions a hardened penetrator using kinetic energy to defeat the target's defenses and subsequently deliver a nuclear explosive to the buried target. The primary difficulty facing the designers of such a penetrator is the tremendous heat applied to
3220-421: A policy of expanded deterrence, which focuses not solely on the would-be nuclear terrorists but on those states that may deliberately transfer or inadvertently leak nuclear weapons and materials to them. By threatening retaliation against those states, the United States may be able to deter that which it cannot physically prevent.". Graham Allison makes a similar case, arguing that the key to expanded deterrence
3360-410: A proliferating message to non-nuclear powers, undermining non-proliferation efforts. Critics also worry that the existence of lower-yield nuclear weapons for relatively limited tactical purposes will lower the threshold for their actual use, thus blurring the sharp line between conventional weapons intended for use and weapons of mass destruction intended only for hypothetical deterrence, and increasing
3500-559: A second successful test in August 2017. Despite claims the Mod 12 has an earth penetrating capability, the weapon does not have the reinforced structure like that of the Mod 11, which is required to function as an earth penetrating weapon. The Mod 11 will be retained in service for the ground penetrating mission. The Mod 12 Life Extension Program continued in 2018 and on 29 June 2018 two successful non-nuclear system qualification flight tests at Tonopah Test Range were reported. In October 2018,
3640-447: A significant portion of their energy from fission reactions used to "trigger" fusion reactions, and fusion reactions can themselves trigger additional fission reactions. Only six countries—the United States , Russia , the United Kingdom , China , France , and India —have conducted thermonuclear weapon tests. Whether India has detonated a "true" multi-staged thermonuclear weapon is controversial. North Korea claims to have tested
3780-475: A similar role as the American Cheyenne Mountain Complex . The timing of the Kosvinsky completion date is regarded as one explanation for U.S. interest in a new nuclear bunker buster and the declaration of the deployment of the Mod 11 in 1997: Kosvinsky is protected by about 1,000 feet (300 m) of granite . The B61 unguided bomb should not be confused with the MGM-1 Matador cruise missile , which
3920-550: 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". Nuclear isomers provide a possible pathway to fissionless fusion bombs. These are naturally occurring isotopes ( Hf being a prominent example) which exist in an elevated energy state. Mechanisms to release this energy as bursts of gamma radiation (as in
4060-459: A target; the Mod 11 nuclear earth-penetrator is accurate to 110–170 meters from the desired detonation location, so it requires a 400-kiloton warhead. The Mod 12 is accurate to 30 meters from a target and only requires a 50-kiloton warhead. Schwartz believes that greater accuracy would both improve the weapon and create a different target set it can be useful against. An example is the higher-yield Mod 11's role of attacking underground bunkers that need
4200-454: Is liquefaction of the concrete in the target, which tends to flow over the projectile. Variation in the speed of the penetrator can either cause it to be vaporized on impact (in the case of traveling too fast), or to not penetrate far enough (in the case of traveling too slowly). An approximation for the penetration depth is obtained with an impact depth formula derived by Sir Isaac Newton . Another school of thought on nuclear bunker busters
4340-454: Is a variable yield ("dial-a-yield" colloquially) dual use tactical and strategic bomb equipped with Full Fuzing Option (FUFO) designed for external carriage by high-speed aircraft. It has a streamlined casing capable of withstanding supersonic flight. The original B61-0 weapon was 141.6 inches (3.60 m) long, with a diameter of 13.3 inches (340 mm) and a basic weight of 715 pounds (324 kg) with most later weapons having approximately
B61 nuclear bomb - Misplaced Pages Continue
4480-457: Is a Full Fuzing Option (FUFO) weapon, meaning it is equipped with the full range of fuzing and delivery options, including air and ground burst fuzing, and free-fall, retarded free-fall and laydown delivery. It has a streamlined casing capable of withstanding supersonic flight and is 11 ft 8 in (3.56 m) long, with a diameter of about 13 inches (33 cm). The basic weight of the B-61
4620-420: 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
4760-488: Is about 700 pounds (320 kg), although the weights of individual weapons may vary depending on version and fuze /retardation configuration. As of 2020, the weapon was undergoing a 12th modification. According to the Federation of American Scientists in 2012, the roughly 400 B61-12s will each cost "more than its weight in gold" - $ 28 million apiece. In 1961 a report was issued indicating Navy and Air Force interest in
4900-721: Is an explosive device that derives its destructive force from nuclear reactions , either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb ), producing a nuclear explosion . Both bomb types release large quantities of energy from relatively small amounts of matter . The first test of a fission ("atomic") bomb released an amount of energy approximately equal to 20,000 tons of TNT (84 TJ ). The first thermonuclear ("hydrogen") bomb test released energy approximately equal to 10 million tons of TNT (42 PJ). Nuclear bombs have had yields between 10 tons TNT (the W54 ) and 50 megatons for
5040-456: Is analogous to identifying a criminal by fingerprints. "The goal would be twofold: first, to deter leaders of nuclear states from selling weapons to terrorists by holding them accountable for any use of their weapons; second, to give leaders every incentive to tightly secure their nuclear weapons and materials." According to the Pentagon's June 2019 " Doctrine for Joint Nuclear Operations " of
5180-403: Is coming up with ways of tracing nuclear material to the country that forged the fissile material. "After a nuclear bomb detonates, nuclear forensics cops would collect debris samples and send them to a laboratory for radiological analysis. By identifying unique attributes of the fissile material, including its impurities and contaminants, one could trace the path back to its origin." The process
5320-481: Is for the purpose of achieving different yields for different situations , and in manipulating design elements to attempt to minimize weapon size, radiation hardness or requirements for special materials, especially fissile fuel or tritium. 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 weapons . The neutron bomb purportedly conceived by Sam Cohen
5460-506: Is identical to the battery used on the B61-7 and is thermally operated, providing 120 seconds of power for the weapon, but initial power is supplied by the MC2238 Pulse Batteries which are activated by the weapon's pullout switches during separation from the aircraft. The weapon contained two neutron generators for initiation, used a 2400 volt 0.6 μF capacitor for neutron generator firing and a 3300 volt 2.0 μF capacitor for
5600-448: Is no evidence that it is feasible beyond the military domain. However, the U.S. 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. A fourth generation nuclear weapon design is related to, and relies upon, the same principle as antimatter-catalyzed nuclear pulse propulsion . Most variation in nuclear weapon design
5740-409: 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
B61 nuclear bomb - Misplaced Pages Continue
5880-490: Is not clear that this has ever been implemented, and their plausible use in nuclear weapons is a matter of dispute. The other basic type of nuclear weapon produces a large proportion of its energy in nuclear fusion reactions. Such fusion weapons are generally referred to as thermonuclear weapons or more colloquially as hydrogen bombs (abbreviated as H-bombs ), as they rely on fusion reactions between isotopes of hydrogen ( deuterium and tritium ). All such weapons derive
6020-430: Is that, while the conventional version is meant for one target, the nuclear version can destroy an entire underground bunker system. The main principles in modern bunker design are largely centered around survivability in nuclear war. As a result of this both American and Soviet sites reached a state of "super hardening", involving defenses against the effects of a nuclear weapon such as spring- or counterweight-mounted (in
6160-401: Is the nuclear equivalent of the conventional bunker buster . The non-nuclear component of the weapon is designed to penetrate soil , rock , or concrete to deliver a nuclear warhead to an underground target. These weapons would be used to destroy hardened, underground military bunkers or other below-ground facilities. An underground explosion releases a larger fraction of its energy into
6300-454: Is the primary means of nuclear weapons delivery; the majority of U.S. nuclear warheads, for example, are free-fall gravity bombs, namely the B61 , which is being improved upon to this day. Preferable from a strategic point of view is a nuclear weapon mounted on a missile , which can use a ballistic trajectory to deliver the warhead over the horizon. Although even short-range missiles allow for
6440-532: Is to reduce the required yield needed to ensure the destruction of the target by coupling the explosion to the ground, yielding a shock wave similar to an earthquake. For example, the United States retired the B-53 warhead , with a yield of nine megatons , because the B-61 Mod 11 could attack similar targets with much lower yield (400 kilotons ), due to the latter's superior ground penetration. By burying itself into
6580-636: Is unlikely the blast would be completely contained. Critics further state that the testing of new nuclear weapons would be prohibited by the proposed Comprehensive Test Ban Treaty . Although Congress refused to ratify the CTBT in 1999, and therefore this treaty has no legal force in the US, the US has adhered to the spirit of the treaty by maintaining a moratorium on nuclear testing since 1992. Proponents, however, contend that lower explosive yield devices and subsurface bursts would produce little to no climatic effects in
6720-432: Is using a light penetrator to travel 15 to 30 meters through shielding, and detonate a nuclear charge there. Such an explosion would generate powerful shock waves, which would be transmitted very effectively through the solid material comprising the shielding (see "scabbing" above). The main criticisms of nuclear bunker busters regard fallout and nuclear proliferation. The purpose of an earth-penetrating nuclear bunker buster
6860-666: The B-21 Raider , but it is not planned to be deployed on the F-35. The Federation of American Scientists have accused the weapon of being a "political bomb", introduced to finally retire the B83-1 nuclear bomb, whose retirement has been blocked by hardliners. A W61 Earth Penetrator Warhead (EPW) with a yield of 340 kilotonnes of TNT (1,400 TJ) was developed for the AGM-129 Advanced Cruise Missile and
7000-740: The B28 and B43 nuclear bombs . The desired production date was June 1965. The weapon was designated the TX-61 in January 1963. Due to the short time-scales, it was decided to make maximum use of off-the-shelf components such as those developed for the B57 nuclear bomb . Environmental conditions specified included an indefinite temperature range of −60 °F (−51 °C) to 160 °F (71 °C), shocks of up to 40g, and in flight temperatures of up to 275 °F (135 °C) for up to 40 minutes. Parachute deployment
7140-1021: The F-22 Raptor 's weapons bays and will also be carried by the Lockheed Martin F-35 Lightning II . B61 tactical variants are deployed with NATO allies in Europe as part of the NATO Nuclear Weapons Sharing Program . About 150 bombs are stored at six bases: Kleine Brogel in Belgium, Büchel Air Base in Germany, Aviano and Ghedi Air Base in Italy, Volkel Air Base in the Netherlands and Incirlik in Turkey. In 2012, NATO agreed to improve
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#17327832972647280-806: The MGM-134 Midgetman small ICBM. The weapon entered Phase 1 initial development in January 1985 and phase 4 production engineering in September 1992 before being cancelled in December of that year. In the Advanced Cruise Missile role, the weapon was to replace aging B53 bombs, but after the W61 cancellation the role was filled by the B61-11 bomb. A declassified technical report on the automation of pit handling at Pantex indicates that
7420-695: 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
7560-453: The Treaty on the Non-Proliferation of Nuclear Weapons (1968) attempted to place restrictions on the types of activities signatories could participate in, with the goal of allowing the transference of non-military nuclear technology to member countries without fear of proliferation. Nuclear bunker buster A nuclear bunker buster , also known as an earth-penetrating weapon ( EPW ),
7700-554: The Tsar Bomba (see TNT equivalent ). A thermonuclear weapon weighing as little as 600 pounds (270 kg) can release energy equal to more than 1.2 megatonnes of TNT (5.0 PJ). A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation . Since they are weapons of mass destruction , the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been deployed twice in war , both by
7840-676: The Tsar Bomba of the USSR, which released an energy equivalent of over 50 megatons of TNT (210 PJ), was a three-stage weapon. Most thermonuclear weapons are considerably smaller than this, due to practical constraints from missile warhead space and weight requirements. In the early 1950s the Livermore Laboratory in the United States had plans for the testing of two massive bombs, Gnomon and Sundial , 1 gigaton of TNT and 10 gigatons of TNT respectively. Fusion reactions do not create fission products, and thus contribute far less to
7980-516: The Valentin submarine pens had ferrous concrete roofs 4.5 metres (15 feet) thick which were penetrated by two Grand Slams on 27 March 1945), but rather to penetrate under the target and explode leaving a camouflet (cavern) which would undermine foundations of structures above, causing it to collapse, thus negating any possible hardening. The destruction of targets such as the V3 battery at Mimoyecques
8120-424: 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. A major obstacle is the difficulty of producing antimatter in large enough quantities, and there
8260-614: The head of government or head of state . Despite controls and regulations governing nuclear weapons, there is an inherent danger of "accidents, mistakes, false alarms, blackmail, theft, and sabotage". In the late 1940s, lack of mutual trust prevented the United States and the Soviet Union from making progress on arms control agreements. The Russell–Einstein Manifesto was issued in London on July 9, 1955, by Bertrand Russell in
8400-506: The percussion cap on an MC4246A thermal battery , powering it up. Electrical power from the thermal battery is sufficient to "fry" the internal circuitry of the bomb, destroying critical mechanisms without causing detonation. This makes the bomb incapable of being used. Any B61 which has had the command disable facility activated must be returned to Pantex for repair. The B61 can be set for airburst or groundburst detonation, and by free fall , retarded free fall or laydown delivery through
8540-436: The tropopause into the stratosphere , where the calm non-turbulent winds permit the debris to travel great distances from the burst, eventually settling and unpredictably contaminating areas far removed from the target of the explosion. 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
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#17327832972648680-537: The "implosion" method, is more sophisticated and more efficient (smaller, less massive, and requiring less of the expensive fissile fuel) than the former. A major challenge in all nuclear weapon designs is to ensure that a significant fraction of the fuel is consumed before the weapon destroys itself. The amount of energy released by fission bombs can range from the equivalent of just under a ton to upwards of 500,000 tons (500 kilotons ) of TNT (4.2 to 2.1 × 10 GJ). All fission reactions generate fission products ,
8820-603: The $ 10 billion cost to refurbish the warheads. The Mod 12 uses an internal guidance system and can glide to its target. On 1 July 2015, the National Nuclear Security Administration (NNSA) conducted the first of three flight tests of the Mod 12 tail kit assembly. According to the Federation of American Scientists in 2012, the roughly 400 B61-12s will cost $ 28 million apiece. [REDACTED] Media related to B61 nuclear bomb at Wikimedia Commons Nuclear bomb A nuclear weapon
8960-533: The 1980s (though not deployed in Europe) for use as tactical payloads for US Army artillery shells (200 mm W79 and 155 mm W82 ) and 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. A type of nuclear explosive most suitable for use by ground special forces
9100-484: The 400 weapons is now expected to cost over $ 10 billion. The Mod 12 tail assembly contract was awarded to Boeing on November 27, 2012 for $ 178 million. Boeing will use their experience with the Joint Direct Attack Munition to yield JDAM-equivalent accuracy in a nuclear bomb. This contract is only the first part of the billion-dollar expense of producing and applying the tail kits, over and above
9240-554: The B-61 Mod 11 in 1997. Kosvinsky is protected by about 300 meters (1000 feet) of granite . The weapon was revisited after the Cold War during the 2001 U.S. invasion of Afghanistan , and again during the 2003 invasion of Iraq . During the campaign in Tora Bora in particular, the United States believed that "vast underground complexes," deeply buried, were protecting opposing forces. Such complexes were not found. While
9380-485: The B61 have been designed, known as Mod 0 through Mod 12. Of these, nine have entered production. Each shares the same physics package , with different yield options. The newest variant is the Mod 11, deployed in 1997, which is a ground-penetrating bunker busting weapon. The Russian Continuity of Government facility at Kosvinsky Kamen , finished in early 1996, was designed to resist US earth-penetrating warheads and serves
9520-687: The B61 is hoped to lead to the retirement of the B83, resulting in the elimination of the last megaton-yield U.S. bomb and leave the B61-series as the only U.S. gravity nuclear bomb. In 2013, the Pentagon and NNSA stated that if B61 refurbishment did not begin by 2019, components in the existing weapons could begin to fail. In 2013 Tom Collina of the Arms Control Association said that the new development could complicate arms control efforts with Russia. In 2014, Congress slashed funding for
9660-689: The B61-2 and B61-5 share a common pit design, as do the B61-3, B61-10 and W85. The B61-0 and B61-4 do not share a pit with any other weapon. As the B61-7 was a retrofit of the B61-1 and the B61-11 was a retrofit of the B61-7, they presumably share a common pit. In May 2010 the National Nuclear Security Administration asked Congress for $ 40 million to redesign the bomb to enable the Lockheed Martin F-35 Lightning II to carry
9800-524: The B61-3 as an "improved Mod 2 w/IHE" and the B61-4 as "same as Mod 3 ex. Hi-Y". The B61 Mod 3 and 4 bombs do not contain beryllium . A 1978 report on reducing or substituting beryllium in nuclear weapons noted that the B61-5 contained beryllium and that if the use of beryllium were to be restricted, the B61-5 could probably be replaced by the B61 Mod 3. The B61 Mod 6 and Mod 8 bombs were developed for use by
9940-425: The Cold War, policy and military theorists considered the sorts of policies that might prevent a nuclear attack, and they developed game theory models that could lead to stable deterrence conditions. Different forms of nuclear weapons delivery (see above) allow for different types of nuclear strategies. The goals of any strategy are generally to make it difficult for an enemy to launch a pre-emptive strike against
10080-494: The Joint Chiefs of Staffs website Publication, "Integration of nuclear weapons employment with conventional and special operations forces is essential to the success of any mission or operation." Because they are weapons of mass destruction, the proliferation and possible use of nuclear weapons are important issues in international relations and diplomacy. In most countries, the use of nuclear force can only be authorized by
10220-637: The MC2935 come from either of the two MC4175s or the MC4137 Trajectory Sensing Signal Generators. A third stronglink existed inside the first exclusion region of the weapon and was involved in weapon arming. Details of the system are still classified. As of 2013 the Pentagon saw the B83 nuclear bomb as a "relic of the Cold War," believing that deploying a megaton-yield gravity bomb, the highest level nuclear weapon left in
10360-557: The MC2969 in the open position until a specific unlock signal was received. The second stronglink was the MC2935 Trajectory Stronglink Switch of which there were two, one for each channel of the weapon's firing set. Like the MC2969, it mechanically locked if it received the wrong input signals, but unlike the MC2969 it could only be manually unlocked, which could only take place at the factory. Signals for
10500-512: The MC4139 and continuously applied power the MC4137 does not know how to arm the safelink. The weapon was to feature a number of weapon stronglinks. Stronglinks are part of the weapon's safety systems and are designed to be robust enough that they can survive abnormal environments long enough for the weapon's weaklinks to fail. This requires weak and stronglinks to be colocated so they are exposed to
10640-468: The Mod 11 went into service in 1997 replacing the older megaton -yield B53 bomb . About 50 Mod 11 bombs have been produced, their warheads converted from Mod 7 bombs. At present, the primary carrier for the Mod 11 is the B-2 Spirit . As of 2023, the B61 has 13 variants, referred to as Mod 0 through Mod 12. A Sandia document on the dates of the development phases of the US nuclear stockpile describes
10780-584: The Mod 12 guided tail-kit assembly received Milestone C approval to enter the production phase; the TKA went through the traditional test program in under 11 months, achieving a 100% success rate for all 31 bomb drops. The B61-12 nuclear bomb completed its successful flight tests with the US Air Force's F-15E in June 2020. It was dropped from above 25,000ft and was in the air for approximately 55 seconds before hitting
10920-503: The Nuclear Age (1961) that mere possession of a nuclear arsenal was enough to ensure deterrence, and thus concluded that the spread of nuclear weapons could increase international stability . Some prominent neo-realist scholars, such as Kenneth Waltz and John Mearsheimer , have argued, along the lines of Gallois, that some forms of nuclear proliferation would decrease the likelihood of total war , especially in troubled regions of
11060-552: The U.S. inventory, to Europe was "inconceivable" at this point. It can also only be carried by the B-2 bomber, and integrating it onto additional aircraft would be costly. The Mod 12 upgrade is being pursued as a forward-deployed tactical/strategic nuclear weapon to protect NATO and Asian allies since it can be used from dual-capable fighter aircraft, as well as planned to arm the F-35 and B-21 Raider , and its lower yield options make it more flexible with less collateral effects. Recapitalizing
11200-419: The U.S. would be more willing to use it in situations where necessary. The improved accuracy would make it more effective than the previous Mod 3/4 currently deployed to the continent. F-16 and Panavia Tornado aircraft cannot interface with the new bomb due to electronic differences, but NATO countries buying the F-35 would be able to utilize it. The first flight test for an inert Mod 12 was conducted in 2015, with
11340-577: The US Navy beginning in March 1987 and cancelled at the end of the Cold War. The weapons weighed 350 kilograms (770 lb), had a length of 3,597 millimetres (141.6 in) and a diameter of 338 millimetres (13.3 in), and were one-point safe, used insensitive high explosives (IHE) in their primary stages and utilized enhanced electrical safety (EES). The weapons were to be built by converting existing B61-0, −2 and −5 weapons into Mod 6 and 8 weapons and
11480-489: The US government of "reducing the nuclear threshold" with the weapon's increased accuracy. The F/A-18E/F Super Hornet is not listed as a future platform. Initially, the NNSA Stockpile Stewardship and Management Plan anticipated Phase 1 development for the B61 Mod 13 Life Extension Program (LEP) beginning in 2037 with first production of the weapon in 2050, but in 2023 plans were announced to produce
11620-664: The USAAF detonated a plutonium implosion-type fission bomb nicknamed " Fat Man " over the Japanese city of Nagasaki . These bombings caused injuries that resulted in the deaths of approximately 200,000 civilians and military personnel . The ethics of these bombings and their role in Japan's surrender are to this day, still subjects of debate . Since the atomic bombings of Hiroshima and Nagasaki , nuclear weapons have been detonated over 2,000 times for testing and demonstration. Only
11760-777: The USAF AIR-2 Genie , the AIM-26 Falcon and US Army Nike Hercules . Missile interceptors such as the Sprint and the Spartan also used small nuclear warheads (optimized to produce neutron or X-ray flux) but were for use against enemy strategic warheads. Other small, or tactical, nuclear weapons were deployed by naval forces for use primarily as antisubmarine weapons. These included nuclear depth bombs or nuclear armed torpedoes. Nuclear mines for use on land or at sea are also possibilities. The system used to deliver
11900-527: The United States against the Japanese cities of Hiroshima and Nagasaki in 1945 during World War II . Nuclear weapons have only twice been used in warfare, both times by the United States against Japan at the end of World War II . On August 6, 1945, the United States Army Air Forces (USAAF) detonated a uranium gun-type fission bomb nicknamed " Little Boy " over the Japanese city of Hiroshima ; three days later, on August 9,
12040-526: The United States. Small, two-man portable tactical weapons (somewhat misleadingly referred to as suitcase bombs ), such as the Special Atomic Demolition Munition , have been developed, although the difficulty of combining sufficient yield with portability limits their military utility. Nuclear warfare strategy is a set of policies that deal with preventing or fighting a nuclear war. The policy of trying to prevent an attack by
12180-419: The United States. The complex fuel storage facilities and equipment needed to fuel missiles for launch and de-fuel them for frequent maintenance add additional weaknesses and vulnerabilities. Therefore, a similar degree of silo "hardening" does not automatically equate to a similar level of missile "survivability". Major advancements in the accuracy and precision of nuclear and conventional weapons subsequent to
12320-447: The atmosphere, generating significant fallout . While conventional bunker busters use several methods to penetrate concrete structures, these are for the purpose of destroying the structure directly, and are generally limited in how much of a bunker (or system of bunkers) they can destroy by depth and their relatively low explosive force (compared to nuclear weapons). The primary difference between conventional and nuclear bunker busters
12460-656: The bunker's depth, rather than above it. Geologic factors also play a major role in weapon effectiveness and facility survivability. Locating facilities in hard rock may appear to reduce the effectiveness of bunker-buster type weapons by decreasing penetration, but the hard rock also transmits shock forces to a far higher degree than softer soil types. The difficulties of drilling into and constructing facilities within hard rock also increase construction time and expense, as well as making it more likely construction will be discovered and new sites targeted by foreign militaries. Concrete structure design has not changed significantly in
12600-468: The capabilities of this force with the increased accuracy of the Mod 12 upgrade and the delivery of the F-35 aircraft. This added a modest standoff capability to the B61. The F-35A was certified to carry the B61-12 in October 2023, marking the first time a fifth generation fighter has been nuclear capable, and the first new platform in the NATO inventory to achieve such status since the early 1990s. The B61
12740-514: The case of the R-36) control capsules and thick concrete walls (3 to 4 feet (0.91 to 1.22 m) for the Minuteman ICBM launch control capsule) heavily reinforced with rebar . These systems were designed to survive a near miss of 20 megatons. Liquid-fueled missiles such as those historically used by Russia are more fragile and easily damaged than solid-fueled missiles such as those used by
12880-485: The chance of a successful missile defense . Today, missiles are most common among systems designed for delivery of nuclear weapons. Making a warhead small enough to fit onto a missile, though, can be difficult. Tactical weapons have involved the most variety of delivery types, including not only gravity bombs and missiles but also artillery shells, land mines , and nuclear depth charges and torpedoes for anti-submarine warfare . An atomic mortar has been tested by
13020-425: The countermeasures involved in the protection of underground bunkers by penetrating the defenses prior to detonating. A relatively low yield may be able to produce seismic forces beyond those of an air burst or even ground burst of a weapon with twice its yield. Additionally, the weapon has the ability to impart more severe horizontal shock waves than many bunker systems are designed to combat by detonating at or near
13160-435: The creation of nuclear fallout than fission reactions, but because all thermonuclear weapons contain at least one fission stage, and many high-yield thermonuclear devices have a final fission stage, thermonuclear weapons can generate at least as much nuclear fallout as fission-only weapons. Furthermore, high yield thermonuclear explosions (most dangerously ground bursts) have the force to lift radioactive debris upwards past
13300-455: The decision process. The prospect of mutually assured destruction might not deter an enemy who expects to die in the confrontation. Further, if the initial act is from a stateless terrorist instead of a sovereign nation, there might not be a nation or specific target to retaliate against. It has been argued, especially after the September 11, 2001, attacks , that this complication calls for
13440-469: The energy of a fission bomb to compress and heat fusion fuel. In the Teller-Ulam design , which accounts for all multi-megaton yield hydrogen bombs, this is accomplished by placing a fission bomb and fusion fuel ( tritium , deuterium , or lithium deuteride ) in proximity within a special, radiation-reflecting container. When the fission bomb is detonated, gamma rays and X-rays emitted first compress
13580-399: The event of a nuclear war, in contrast to multi-megaton air and surface bursts (that is, if the nuclear winter hypothesis proves accurate). Lower fuzing heights , which would result from partially buried warheads, would limit or completely obstruct the range of the burning thermal rays of a nuclear detonation, therefore limiting the target, and its surroundings, to a fire hazard by reducing
13720-554: The firing set. If neither the radar fuze or the contact crystals actuated, the weapon would detonate at 120 seconds from arming. The weapons were to initially use the MC4175 Trajectory Sensing Signal Generators which are identical to the TSSG found in the B61-7, but starting from 1991, the Mod 6 was to get a new MC4137 Trajectory Sensing Signal Generator. The MC4175 stored the arming signal for
13860-455: 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
14000-420: The fusion fuel, then heat it to thermonuclear temperatures. The ensuing fusion reaction creates enormous numbers of high-speed neutrons , which can then induce fission in materials not normally prone to it, such as depleted uranium . Each of these components is known as a "stage", with the fission bomb as the "primary" and the fusion capsule as the "secondary". In large, megaton-range hydrogen bombs, about half of
14140-535: 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
14280-523: The ground before detonation, a much higher proportion of the explosion energy is transferred to seismic shock when compared to the surface burst produced from the B-53's laydown delivery . Moreover, the globally dispersed fallout of an underground B-61 Mod 11 would likely be less than that of a surface burst B-53. Supporters note that this is one of the reasons nuclear bunker busters should be developed. Critics claim that developing new nuclear weapons sends
14420-434: The ground, compared to a surface burst or air burst explosion at or above the surface, and so can destroy an underground target using a lower explosive yield . This in turn could lead to a reduced amount of radioactive fallout . However, it is unlikely that the explosion would be completely contained underground. As a result, significant amounts of rock and soil would be rendered radioactive and lofted as dust or vapor into
14560-461: The initial crater, a crushed aggregate surrounding the crater, and "scabbing" on the surface opposite the crater. Scabbing, also known as spalling , is the violent separation of a mass of material from the opposite face of a plate or slab subjected to an impact or impulsive loading, without necessarily requiring that the barrier itself be penetrated. While soil is a less dense material, it also does not transmit shock waves as well as concrete. So while
14700-506: The invention of the missile silo itself have also rendered many "hardening" technologies useless. With modern weapons capable of striking within feet (meters) of their intended targets, a modern "near miss" can be much more effective than a "hit" decades ago. A weapon need only cover the silo door with sufficient debris to prevent its immediate opening to render the missile inside useless for its intended mission of rapid strike or counter-strike deployment. A nuclear bunker buster negates most of
14840-494: The last 70 years. The majority of protected concrete structures in the U.S. military are derived from standards set forth in Fundamentals of Protective Design , published in 1946 (US Army Corps of Engineers). Various augmentations, such as glass , fibers , and rebar , have made concrete less vulnerable, but far from impenetrable. When explosive force is applied to concrete, three major fracture regions are usually formed:
14980-496: The majority of their energy from nuclear fission reactions alone, and those that use fission reactions to begin nuclear fusion reactions that produce a large amount of the total energy output. All existing nuclear weapons derive some of their explosive energy from nuclear fission reactions. Weapons whose explosive output is exclusively from fission reactions are commonly referred to as atomic bombs or atom bombs (abbreviated as A-bombs ). This has long been noted as something of
15120-407: The midst of the Cold War. It highlighted the dangers posed by nuclear weapons and called for world leaders to seek peaceful resolutions to international conflict. The signatories included eleven pre-eminent intellectuals and scientists, including Albert Einstein , who signed it just days before his death on April 18, 1955. A few days after the release, philanthropist Cyrus S. Eaton offered to sponsor
15260-545: The military establishment have questioned the usefulness of such weapons in the current military climate. According to an advisory opinion issued by the International Court of Justice in 1996, the use of (or threat of use of) such weapons would generally be contrary to the rules of international law applicable in armed conflict, but the court did not reach an opinion as to whether or not the threat or use would be lawful in specific extreme circumstances such as if
15400-408: The missiles before they land or implementing civil defense measures using early-warning systems to evacuate citizens to safe areas before an attack. Weapons designed to threaten large populations or to deter attacks are known as strategic weapons . Nuclear weapons for use on a battlefield in military situations are called tactical weapons . Critics of nuclear war strategy often suggest that
15540-407: The multi-megaton thermonuclear weapons developed in the 1950s and 1960s. Bunker penetration weapons were initially designed within this Cold War context. One likely Soviet Union/Russian target, Mount Yamantau , was regarded in the 1990s by Maryland Republican congressman, Roscoe Bartlett , as capable of surviving "half a dozen" repeated nuclear strikes of an unspecified yield, one after the other in
15680-536: The nuclear B61 , and conventional thermobaric weapons and GBU-28 . One of the more effective housings, the GBU-28 used its large mass (2,130 kg or 4,700 lb) and casing (constructed from barrels of surplus 203 mm howitzers ) to penetrate 6 meters (20 feet) of concrete, and more than 30 metres (98 feet) of earth. The B61 Mod 11, which first entered military service after the Cold war had ended, in January 1997,
15820-646: The nuclear bunker-buster has been dropped from the U.S. Department of Energy 's 2006 budget at the department's request. While the project for the RNEP seems to be in fact canceled, Jane's Information Group speculated in 2005 that work might continue under another name. A more recent development (c. 2012) is the GBU-57 Massive Ordnance Penetrator, a 30,000 pound (14,000 kg) conventional gravity bomb. The USAF's B-2 Spirit bombers can each carry two such weapons. Note that with
15960-566: The original TX-61 design, and the Department of Defense was unfavorable to the second option which halted its exploration. The TX-61 design was ordered to "proceed along the lines" of the third alternative in May 1964, though it is unclear what that means. Total production of all versions was approximately 3,155, of which approximately 540 remain in active service, 415 in inactive service and 520 are awaiting dismantlement as of 2012. 13 versions of
16100-658: The penetrator unit when striking the shielding (surface) at hundreds of meters per second. This has partially been solved by using metals such as tungsten (the metal with the highest melting point), and altering the shape of the projectile (such as an ogive ). Altering the shape of the projectile to incorporate an ogive shape has yielded substantial improvement in penetration ability. Rocket sled testing at Eglin Air Force Base has demonstrated penetrations of 100 to 150 feet (30 to 46 m) in concrete when traveling at 4,000 ft/s (1,200 m/s). The reason for this
16240-446: The pilot. The weapon can be released at speeds up to Mach 2 and altitudes as low as 50 feet (15 m). In one of the weapon's laydown modes, it detonates 31 seconds after weapon release. The Mod 11 is a hardened penetration bomb with a reinforced casing and a delayed-action fuze ; this allows the weapon to penetrate several metres into the ground before detonating, damaging fortified structures further underground. Developed from 1994,
16380-408: The project and called for alternates to be studied. In January 2014, former Air Force Chief of Staff Norton A. Schwartz stated that the Mod 12 nuclear bomb upgrade would have enhanced accuracy and a lower yield with less fallout compared to previous versions of the weapon. Accuracy has not been a guarantee for air-dropped nuclear weapons, so consequently large warheads were needed to effectively impact
16520-702: The range of thermal radiation with fuzing for subsurface bursts. Professors Altfeld and Cimbala have suggested that belief in the possibility of nuclear winter has actually made nuclear war more likely, contrary to the views of Carl Sagan and others, because it has inspired the development of more accurate, and lower explosive yield, nuclear weapons. As early as 1944, the Barnes Wallis Tallboy bomb and subsequent Grand Slam weapons were designed to penetrate deeply fortified structures through sheer explosive power. These were not designed to directly penetrate defences, though they could do this (for example,
16660-428: The remains of the split atomic nuclei. Many fission products are either highly radioactive (but short-lived) or moderately radioactive (but long-lived), and as such, they are a serious form of radioactive contamination . Fission products are the principal radioactive component of nuclear fallout . Another source of radioactivity is the burst of free neutrons produced by the weapon. When they collide with other nuclei in
16800-454: The risk of escalation to higher-yield nuclear weapons. Local fallout from any nuclear detonation is increased with proximity to the ground. While a megaton-class yield surface burst will inevitably throw up many tons of (newly) radioactive debris, which falls back to the earth as fallout, critics contend that despite their relatively minuscule explosive yield, nuclear bunker busters create more local fallout per kiloton yield. Also, because of
16940-470: The safety/arming and firing mechanisms. The other socket is the PAL connector, which has 23 pins marked with alphabetic letter codes. The B61 "command disable" mechanism functions as follows: after entering the correct three-digit numeric code it is then possible to turn a dial to "DI" and pull back a T-shaped handle which comes away in the user's hand. This action releases a spring-loaded firing pin which fires
17080-462: The same dimensions and weight, except for the Mod 11 version which has a weight of approximately 1,200 pounds (540 kg). The B61 is armed by ground-based personnel via an access panel located on the side of the bomb, which opens to reveal nine dials, two sockets, and a T-handle which manually triggers the "command disable" function. One of the sockets is for a MC4142 "strike enable" plug which must be inserted in order to complete critical circuits in
17220-487: The same environmental conditions in an accident. The first stronglink was the MC2969 Intent Stronglink Switch which was also used on the B61-3, −4 and −7, W78, W80 and B83 weapons. The MC2969 consisted of a 14-pin ceramic-insulated bank of switches that would close upon the receipt of the proper intent unique signal (IUQS) to its electromechanical decoder. Receipt of the wrong signal would lock
17360-533: The subsurface detonation, radioactive debris may contaminate the local groundwater. The Union of Concerned Scientists advocacy group points out that at the Nevada Test Site , the depth required to contain fallout from an average-yield underground nuclear test was over 100 meters, depending upon the weapon's yield. They contend that it is improbable that penetrators could be made to burrow so deeply. With yields between 0.3 and 340 kilotons, they argue, it
17500-402: The surrounding material, the neutrons transmute those nuclei into other isotopes, altering their stability and making them radioactive. The most commonly used fissile materials for nuclear weapons applications have been uranium-235 and plutonium-239 . Less commonly used has been uranium-233 . Neptunium-237 and some isotopes of americium may be usable for nuclear explosives as well, but it
17640-498: The survival of the state were at stake. Another deterrence position is that nuclear proliferation can be desirable. In this case, it is argued that, unlike conventional weapons, nuclear weapons deter all-out war between states, and they succeeded in doing this during the Cold War between the U.S. and the Soviet Union . In the late 1950s and early 1960s, Gen. Pierre Marie Gallois of France, an adviser to Charles de Gaulle , argued in books like The Balance of Terror: Strategy for
17780-659: The target. The first B61-12 bomb was produced in November 2021. The weapon replaces the B61 mod 3, mod 4 and mod 7 bombs while the B61-11 will be retained in the stockpile. It is expected that the LEP will extend the B61's life by at least 20 years. Politico reported in October 2022 that the US military planned to accelerate the deployment of the Mod 12 in Europe. This drew criticism from the Russian Deputy Minister of Foreign Affairs Alexander Grushko , who accused
17920-538: The trajectory stronglink in its memory, so it featured a pair of rolamite acceleration switches designed to prevent the possibility of the signal being transferred to the stronglink before the rolamites were actuated by the spinning of the weapon in flight. The MC4137 instead is provided the unique signal from the MC4139 Programmer, which stores it in a volatile memory that erases after approximately seven seconds of lost power, meaning that without intent from
18060-446: The use of a parachute to slow down the weapon during release from the delivery aircraft. Only the Mod 0 to 10 versions of the B61 are equipped with a parachute retarder (currently a 24-ft (7.3 m) diameter nylon / Kevlar chute). This offers the aircraft a chance to escape the blast in its retarded delivery modes, or allows the weapon to survive impact with the ground in laydown delivery mode. Contact preclusion can also be selected by
18200-566: The weapon internally by 2017. This version is designated Mod 12. The four hundred Mod 12 bombs will be used by both tactical aircraft (such as the F-35) and strategic aircraft (such as the B-2) and the Tail Subassembly (TSA) will give them Joint Direct Attack Munition levels of accuracy, allowing the fifty kiloton warhead to have strategic effects from all carrying aircraft. However, refitting
18340-446: The weapon system and difficult to defend against the delivery of the weapon during a potential conflict. This can mean keeping weapon locations hidden, such as deploying them on submarines or land mobile transporter erector launchers whose locations are difficult to track, or it can mean protecting weapons by burying them in hardened missile silo bunkers. Other components of nuclear strategies included using missile defenses to destroy
18480-557: The weapons were to use B61-7 weapon parts where possible. By mass, the largest deviations from the B61-7 were the Acorn assembly, MC4137 TSSG (trajectory sensing signal generator) and the JTA (described as "ballast for WR"). The weapon's computer was the MC4139 Programmer, two of which are used on independent channels, and is identical to the programmer used on the B61-7. The MC3656 Main Battery
18620-631: The world where there exists a single nuclear-weapon state. Aside from the public opinion that opposes proliferation in any form, there are two schools of thought on the matter: those, like Mearsheimer, who favored selective proliferation, and Waltz, who was somewhat more non- interventionist . Interest in proliferation and the stability-instability paradox that it generates continues to this day, with ongoing debate about indigenous Japanese and South Korean nuclear deterrent against North Korea . The threat of potentially suicidal terrorists possessing nuclear weapons (a form of nuclear terrorism ) complicates
18760-624: The yield comes from the final fissioning of depleted uranium. Virtually all thermonuclear weapons deployed today use the "two-stage" design described to the right, but it is possible to add additional fusion stages—each stage igniting a larger amount of fusion fuel in the next stage. This technique can be used to construct thermonuclear weapons of arbitrarily large yield. This is in contrast to fission bombs, which are limited in their explosive power due to criticality danger (premature nuclear chain reaction caused by too-large amounts of pre-assembled fissile fuel). The largest nuclear weapon ever detonated,
18900-592: Was originally developed under the bomber designation B-61. The B61 has been deployed by a variety of US military aircraft. US aircraft cleared for its use have included the B-1 Lancer , B-2 Spirit , B-52 Stratofortress , F/A-18 Hornet , A-6 Intruder , A-4 Skyhawk , F-111 , F-15E Strike Eagle and F-16 Fighting Falcon and the F-35A . As part of NATO Nuclear Weapons Sharing, German and Italian Panavia Tornado aircraft can also carry B61s. The B61 can fit inside
19040-400: Was possible and that such a program could be completed in a short time-span, possibly by 1965 or 1966. Development of the weapon that would become the B61 was authorized in December 1962. The justification for the program was that the new weapon would modernize the nuclear arsenal, improve the capability of aircraft and simplify the nuclear weapons inventory by replacing lower-yield versions of
19180-407: Was specifically developed to allow for bunker penetration, and is speculated to have the ability to destroy hardened targets a few hundred feet beneath the earth. While penetrations of 20–100 feet (6.1–30.5 m) were sufficient for some shallow targets, both the Soviet Union and the United States were creating bunkers buried under huge volumes of soil or reinforced concrete in order to withstand
19320-632: Was specified to produce a maximum load of 255 g (2,500 m/s). The weapon was designed and built by the Los Alamos National Laboratory in New Mexico . Production engineering began in 1965, with the first war-reserve B61-0 weapon accepted by the AEC in December 1966. However production was halted in May 1967 for design modifications to be made before resuming in January 1968. Shot Flintlock Halfbeak in June 1966 may have been
19460-744: Was the Special Atomic Demolition Munition , or SADM, sometimes popularly known as a 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. Small "tactical" nuclear weapons were deployed for use as antiaircraft weapons. Examples include
19600-512: Was the first operational use of the Tallboy. One bored through a hillside and exploded in the Saumur rail tunnel about 18 m (59 ft) below, completely blocking it, and showing that these weapons could destroy any hardened or deeply excavated installation. Modern targeting techniques allied with multiple strikes could perform a similar task. Development continued, with weapons such as
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