Neutron bomb
Encyclopedia
A neutron bomb or enhanced radiation weapon (ERW) or weapon of reinforced radiation is a type of thermonuclear weapon designed specifically to release a large portion of its energy
as energetic neutron radiation
rather than explosive energy
. Although their extreme blast and heat effects are not eliminated, it is the enormous radiation released by ERWs that is meant to be a major source of casualties. The levels of neutron radiation released are able to penetrate through thick, protective materials such as armor, making them useful as an anti-tank weapon.
thermonuclear weapon (hydrogen bomb) in which the burst of neutrons generated by a fusion
reaction is intentionally allowed to escape the weapon, rather than being absorbed by its other components. The weapon's X-ray
mirrors and radiation case, made of uranium
or lead
in a standard bomb, are instead made of chromium
or nickel
so that the neutrons can escape. The bombs also require amounts of tritium
on the order of a few tens of grams.
The "usual" nuclear weapon yield
—expressed as kT TNT equivalent
—is not a measure of a neutron weapon's destructive power. It refers only to the energy released (mostly heat and blast), and does not express the lethal effect of neutron radiation on living organisms. Compared to a fission bomb with the identical explosive yield, a neutron bomb would emit about ten times the amount of neutron radiation. In a fission bomb, radiation pulse energy is approximately 5% of entire energy released; in the neutron bomb it would be closer to 50%. Neutron bombs release a much higher amount of neutrons than a fission bomb of the same explosive yield. Furthermore, these neutrons are of much higher energy (14 MeV) than those release during a fission reaction (1-2 MeV).
, who developed the concept in 1958. Testing was authorized and carried out in 1963 at an underground Nevada test facility. Development was subsequently postponed by President Jimmy Carter
in 1978 following protests against his administration's plans to deploy neutron warheads in Europe. President Ronald Reagan
restarted production in 1981.
Three types of ERW were built by the United States. The W66
warhead, for the anti-ICBM Sprint
missile system, was deployed in 1975 and retired the next year, along with the missile system. The W70 Mod 3
warhead was developed for the short-range, tactical Lance missile, and the W79 Mod 0
was developed for artillery shells. The latter two types were retired by President George H. W. Bush
in 1992, following the end of the Cold War
. The last W70 Mod 3
warhead was dismantled in 1996, and the last W79 Mod 0 was dismantled by 2003, when the dismantling of all W79 variants was completed.
Besides the United States and Soviet Union, France and China are understood to have tested neutron or enhanced radiation bombs in the past, with France apparently leading the field with an early test of the technology in 1967 and an "actual" neutron bomb in 1980. The 1999 Cox Report
indicates that China is able to produce neutron bombs, although no country is currently known to deploy them.
Considerable controversy arose in the U.S. and Western Europe, following a June 1977 Washington Post exposé describing U.S. government plans to purchase the bomb. The article focused on the fact that it was the first weapon specifically intended to kill humans with radiation. Lawrence Livermore National Laboratory
director Harold Brown
and Soviet General Secretary Leonid Brezhnev
both described the neutron bomb as a "capitalist bomb", because it was designed to destroy people while preserving property.
of high-energy neutrons is intended as the principal killing mechanism, not the fallout, heat or blast. Although neutron bombs are commonly believed to "leave the infrastructure intact", current designs have explosive yields in the kiloton range, the detonation of which would cause considerable destruction through blast and heat effects.
Neutron bombs could be used as strategic anti-ballistic missile
weapons or as tactical weapons intended for use against armored forces. The neutron bomb was originally conceived by the U.S. military as a weapon that could stop Soviet
troops from overrunning allied nations without destroying the infrastructure of the allied nation.
. Armored fighting vehicles offer a relatively high degree of protection against heat and blast, the primary destructive mechanisms of normal nuclear weapons. That is, military personnel inside a tank can be expected to survive an "ordinary" nuclear explosion at relatively close range, while the vehicle's nuclear/biological/chemical
protection systems ensure a high degree of operability even in a nuclear fallout
environment.
ER weapons are meant to kill a much higher percentage of enemy personnel inside such protected environments through the release of a higher percentage of their yield in the form of neutron ionizing radiation
, against which tank armors, excluding depleted uranium
, are ineffective.
s is cited as one of the main reasons why these weapons are no longer fielded or stockpiled. With the increase in average tank armor thickness since the first ER weapons were fielded, tank armor protection approaches the level where tank crews are now almost completely protected from radiation effects. Therefore for an ER weapon to incapacitate a modern tank crew through irradiation, the weapon must now be detonated at such a close proximity to the tank that the nuclear explosion
's blast would now be equally effective at incapacitating it and its crew.
missile system as part of the Safeguard Program
to protect United States cities and missile silos from incoming Soviet
warheads by damaging their electronic components with the intense neutron flux
.
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
as energetic neutron radiation
Neutron radiation
Neutron radiation is a kind of ionizing radiation which consists of free neutrons. A result of nuclear fission or nuclear fusion, it consists of the release of free neutrons from atoms, and these free neutrons react with nuclei of other atoms to form new isotopes, which, in turn, may produce...
rather than explosive energy
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...
. Although their extreme blast and heat effects are not eliminated, it is the enormous radiation released by ERWs that is meant to be a major source of casualties. The levels of neutron radiation released are able to penetrate through thick, protective materials such as armor, making them useful as an anti-tank weapon.
Detailed description
A neutron bomb is a fission-fusionTeller-Ulam design
The Teller–Ulam design is the nuclear weapon design concept used in most of the world's nuclear weapons. It is colloquially referred to as "the secret of the hydrogen bomb" because it employs hydrogen fusion, though in most applications the bulk of its destructive energy comes from uranium fission,...
thermonuclear weapon (hydrogen bomb) in which the burst of neutrons generated by a fusion
Nuclear fusion
Nuclear fusion is the process by which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. This is usually accompanied by the release or absorption of large quantities of energy...
reaction is intentionally allowed to escape the weapon, rather than being absorbed by its other components. The weapon's X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
mirrors and radiation case, made of uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
or lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
in a standard bomb, are instead made of chromium
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...
or nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
so that the neutrons can escape. The bombs also require amounts of tritium
Tritium
Tritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons...
on the order of a few tens of grams.
The "usual" nuclear weapon yield
Nuclear weapon yield
The explosive yield of a nuclear weapon is the amount of energy discharged when a nuclear weapon is detonated, expressed usually in the equivalent mass of trinitrotoluene , either in kilotons or megatons , but sometimes also in terajoules...
—expressed as kT TNT equivalent
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...
—is not a measure of a neutron weapon's destructive power. It refers only to the energy released (mostly heat and blast), and does not express the lethal effect of neutron radiation on living organisms. Compared to a fission bomb with the identical explosive yield, a neutron bomb would emit about ten times the amount of neutron radiation. In a fission bomb, radiation pulse energy is approximately 5% of entire energy released; in the neutron bomb it would be closer to 50%. Neutron bombs release a much higher amount of neutrons than a fission bomb of the same explosive yield. Furthermore, these neutrons are of much higher energy (14 MeV) than those release during a fission reaction (1-2 MeV).
History
Conception of the neutron bomb is generally credited to Samuel T. Cohen of the Lawrence Livermore National LaboratoryLawrence Livermore National Laboratory
The Lawrence Livermore National Laboratory , just outside Livermore, California, is a Federally Funded Research and Development Center founded by the University of California in 1952...
, who developed the concept in 1958. Testing was authorized and carried out in 1963 at an underground Nevada test facility. Development was subsequently postponed by President Jimmy Carter
Jimmy Carter
James Earl "Jimmy" Carter, Jr. is an American politician who served as the 39th President of the United States and was the recipient of the 2002 Nobel Peace Prize, the only U.S. President to have received the Prize after leaving office...
in 1978 following protests against his administration's plans to deploy neutron warheads in Europe. President Ronald Reagan
Ronald Reagan
Ronald Wilson Reagan was the 40th President of the United States , the 33rd Governor of California and, prior to that, a radio, film and television actor....
restarted production in 1981.
Three types of ERW were built by the United States. The W66
W66
The W66 thermonuclear warhead was used on the Sprint anti-ballistic missile system, designed to be a short range interceptor to shoot down incoming ICBM warheads....
warhead, for the anti-ICBM Sprint
Sprint (missile)
The Sprint was a two-stage, solid-fuel anti-ballistic missile, armed with a W66 enhanced radiation thermonuclear warhead. It was designed as the short-range high-speed counterpart to the longer-range LIM-49 Spartan as part of the Sentinel program. Sentinel never became operational, but the...
missile system, was deployed in 1975 and retired the next year, along with the missile system. The W70 Mod 3
W70
W70 is the designation for a tactical nuclear warhead developed by the United States in the early 1970s. The Lawrence Livermore National Laboratory designed W70 was used on the MGM-52 Lance. About 1250 were built in total. The warhead had a variable yield of between 1 and 100 kilotons, selectable...
warhead was developed for the short-range, tactical Lance missile, and the W79 Mod 0
W79
The W79 was an American nuclear artillery shell, fired from any standard 8 inch howitzer e.g. the M115.The W79 was produced in two models, the "W79 Mod 0" and "W79 Mod 1"...
was developed for artillery shells. The latter two types were retired by President George H. W. Bush
George H. W. Bush
George Herbert Walker Bush is an American politician who served as the 41st President of the United States . He had previously served as the 43rd Vice President of the United States , a congressman, an ambassador, and Director of Central Intelligence.Bush was born in Milton, Massachusetts, to...
in 1992, following the end of the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...
. The last W70 Mod 3
W70
W70 is the designation for a tactical nuclear warhead developed by the United States in the early 1970s. The Lawrence Livermore National Laboratory designed W70 was used on the MGM-52 Lance. About 1250 were built in total. The warhead had a variable yield of between 1 and 100 kilotons, selectable...
warhead was dismantled in 1996, and the last W79 Mod 0 was dismantled by 2003, when the dismantling of all W79 variants was completed.
Besides the United States and Soviet Union, France and China are understood to have tested neutron or enhanced radiation bombs in the past, with France apparently leading the field with an early test of the technology in 1967 and an "actual" neutron bomb in 1980. The 1999 Cox Report
Cox Report
The Report of the Select Committee on U.S. National Security and Military/Commercial Concerns with the People's Republic of China, commonly known as the Cox Report after Representative Christopher Cox, is a classified U.S...
indicates that China is able to produce neutron bombs, although no country is currently known to deploy them.
Considerable controversy arose in the U.S. and Western Europe, following a June 1977 Washington Post exposé describing U.S. government plans to purchase the bomb. The article focused on the fact that it was the first weapon specifically intended to kill humans with radiation. Lawrence Livermore National Laboratory
Lawrence Livermore National Laboratory
The Lawrence Livermore National Laboratory , just outside Livermore, California, is a Federally Funded Research and Development Center founded by the University of California in 1952...
director Harold Brown
Harold Brown (Secretary of Defense)
Harold Brown , American scientist, was U.S. Secretary of Defense from 1977 to 1981 in the cabinet of President Jimmy Carter. He had previously served in the Lyndon Johnson administration as Director of Defense Research and Engineering and Secretary of the Air Force.While Secretary of Defense, he...
and Soviet General Secretary Leonid Brezhnev
Leonid Brezhnev
Leonid Ilyich Brezhnev – 10 November 1982) was the General Secretary of the Central Committee of the Communist Party of the Soviet Union , presiding over the country from 1964 until his death in 1982. His eighteen-year term as General Secretary was second only to that of Joseph Stalin in...
both described the neutron bomb as a "capitalist bomb", because it was designed to destroy people while preserving property.
Use of neutron bomb
Neutron bombs are purposely designed with explosive yields lower than other nuclear weapons. This is because neutrons are absorbed by air, so a high-yield neutron bomb is not able to radiate neutrons beyond its blast range and so would have no destructive advantage over a normal hydrogen bomb. This intense pulsePulse (physics)
In physics, a pulse is a single disturbance that moves through a medium from one point to the next point.-Pulse Reflection:Consider a pulse moving through a medium - perhaps through a rope or a slinky. When the pulse reaches the end of that medium, what happens to it depends on whether the medium...
of high-energy neutrons is intended as the principal killing mechanism, not the fallout, heat or blast. Although neutron bombs are commonly believed to "leave the infrastructure intact", current designs have explosive yields in the kiloton range, the detonation of which would cause considerable destruction through blast and heat effects.
Neutron bombs could be used as strategic anti-ballistic missile
Anti-ballistic missile
An anti-ballistic missile is a missile designed to counter ballistic missiles .A ballistic missile is used to deliver nuclear, chemical, biological or conventional warheads in a ballistic flight trajectory. The term "anti-ballistic missile" describes any antimissile system designed to counter...
weapons or as tactical weapons intended for use against armored forces. The neutron bomb was originally conceived by the U.S. military as a weapon that could stop Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
troops from overrunning allied nations without destroying the infrastructure of the allied nation.
Use against armor
One of the uses for which this weapon was conceived is large-scale anti-tank weaponryAnti-tank warfare
Anti-tank warfare was created by the need to seek technology and tactics to destroy tanks and their supporting infantry during the First World War...
. Armored fighting vehicles offer a relatively high degree of protection against heat and blast, the primary destructive mechanisms of normal nuclear weapons. That is, military personnel inside a tank can be expected to survive an "ordinary" nuclear explosion at relatively close range, while the vehicle's nuclear/biological/chemical
Weapons of mass destruction
A weapon of mass destruction is a weapon that can kill and bring significant harm to a large number of humans and/or cause great damage to man-made structures , natural structures , or the biosphere in general...
protection systems ensure a high degree of operability even in a nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
environment.
ER weapons are meant to kill a much higher percentage of enemy personnel inside such protected environments through the release of a higher percentage of their yield in the form of neutron ionizing radiation
Ionizing radiation
Ionizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons...
, against which tank armors, excluding depleted uranium
Depleted uranium
Depleted uranium is uranium with a lower content of the fissile isotope U-235 than natural uranium . Uses of DU take advantage of its very high density of 19.1 g/cm3...
, are ineffective.
Questionable effectiveness in modern anti-tank role
The questionable effectiveness of ER weapons against modern tankTank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...
s is cited as one of the main reasons why these weapons are no longer fielded or stockpiled. With the increase in average tank armor thickness since the first ER weapons were fielded, tank armor protection approaches the level where tank crews are now almost completely protected from radiation effects. Therefore for an ER weapon to incapacitate a modern tank crew through irradiation, the weapon must now be detonated at such a close proximity to the tank that the nuclear explosion
Nuclear explosion
A nuclear explosion occurs as a result of the rapid release of energy from an intentionally high-speed nuclear reaction. The driving reaction may be nuclear fission, nuclear fusion or a multistage cascading combination of the two, though to date all fusion based weapons have used a fission device...
's blast would now be equally effective at incapacitating it and its crew.
Use against ballistic missiles
As an anti-ballistic missile weapon, an ER warhead was developed for the SprintSprint (missile)
The Sprint was a two-stage, solid-fuel anti-ballistic missile, armed with a W66 enhanced radiation thermonuclear warhead. It was designed as the short-range high-speed counterpart to the longer-range LIM-49 Spartan as part of the Sentinel program. Sentinel never became operational, but the...
missile system as part of the Safeguard Program
Safeguard Program
The Safeguard Program was a United States Army anti-ballistic missile system developed during the late 1960s. Safeguard was designed to protect U.S. ICBM missile sites from counterforce attack, thus preserving the option of an unimpeded retaliatory strike. Safeguard used much of the same technology...
to protect United States cities and missile silos from incoming Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
warheads by damaging their electronic components with the intense neutron flux
Neutron flux
The neutron flux is a quantity used in reactor physics corresponding to the total length travelled by all neutrons per unit time and volume . The neutron fluence is defined as the neutron flux integrated over a certain time period....
.
See also
- Nuclear falloutNuclear falloutFallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
- Nuclear strategyNuclear strategyNuclear strategy involves the development of doctrines and strategies for the production and use of nuclear weapons.As a sub-branch of military strategy, nuclear strategy attempts to match nuclear weapons as means to political ends...
- Nuclear warfareNuclear warfareNuclear warfare, or atomic warfare, is a military conflict or political strategy in which nuclear weaponry is detonated on an opponent. Compared to conventional warfare, nuclear warfare can be vastly more destructive in range and extent of damage...
- Nuclear weapon designNuclear weapon designNuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three basic design types...
Further reading
- Cohen, Sam, The Truth About the Neutron Bomb: The Inventor of the Bomb Speaks Out, William Morrow & Co., 1983, ISBN 0-688-01646-4
- Cohen, Sam, "Shame: Confessions of the Father of the Neutron Bomb", Xlibris Corporation, 2000, ISBN 0-7388-2230-2
External links
- Strategic Implications of Enhanced Radiation Weapons
- Nuclear Files.org Definition and history of the neutron bomb