Pure fusion weapon
Encyclopedia
A pure fusion weapon is a hypothetical hydrogen bomb design
that does not need a fission
"primary" explosive to ignite the fusion
of deuterium
and tritium
, two heavy isotope
s of hydrogen
(see Teller-Ulam design
for more information about fission-fusion weapons). Such a weapon would require no fissile material and would therefore be much easier to build in secret than existing weapons. The necessity of separating high-quality fissile material requires a substantial industrial investment, and blocking the sale and transfer of the needed machinery has been the primary mechanism to control nuclear proliferation
to date.
For many years, nuclear weapon
designers have researched whether it is possible to create high enough temperatures and pressures inside a confined space to fuse together deuterium and tritium for the purposes of developing such a weapon. Pure fusion weapons offer the possibility of generating very small nuclear yields and the advantage of reduced collateral damage stemming from fallout
because these weapons would not create the highly radioactive byproducts associated with fission-type weapons. These weapons would be lethal not only because of their explosive force, which could be large compared to bombs based on chemical explosives, but also because of the neutrons
they generate. The neutrons may cause substantially more casualties than the explosive blast, as in a neutron bomb
.
Despite the many millions of dollars spent by the U.S. between 1952 and 1992 to produce a pure fusion weapon, no measurable success was ever achieved. In 1998, the U.S. Department of Energy (DOE) released a restricted data declassification decision stating that even if the DOE made a substantial investment in the past to develop a pure fusion weapon, "the U.S. Is not known to have and is not developing a pure fusion weapon and no credible design for a pure fusion weapon resulted from the DOE investment". The power densities needed to ignite a fusion reaction still seem attainable only with the aid of a fission explosion, or with large apparatus such as powerful laser
s like those at the National Ignition Facility
, the Sandia Z-pinch machine
, or various magnetic tokamak
s. Regardless of any claimed advantages of pure fusion weapons, building those weapons does not appear to be feasible using currently available technologies and many have expressed concern that pure fusion weapons research and development would subvert the intent of the Nuclear Non-Proliferation Treaty
and the Comprehensive Test Ban Treaty
.
It has been claimed that it is possible to conceive of a crude, deliverable, pure fusion weapon, using only current day, unclassified technology. The weapon design weighs approximately 3 tonnes, and might have a total yield of approximately 3 tonnes of TNT. The proposed design uses a large explosively pumped flux compression generator
to produce the high power density required to ignite the fusion fuel. From the point of view of explosive damage, such a weapon would have no clear advantages over a conventional explosive, but the massive neutron flux could deliver a lethal dose of radiation to humans within a 500m radius (most of those fatalities would occur over a period of months, rather than immediately).
Some researchers have examined the use of antimatter
as an alternative fusion trigger, mainly in the context of antimatter catalyzed nuclear pulse propulsion
. Such a system, in a weapons context, would have many of the desired properties of a pure fusion weapon. However, the technical barriers to producing and containing the required quantities of antimatter appear formidable, well beyond present capabilities. Induced gamma emission
is another approach that is currently being researched. Very high energy-density chemicals such as the mythical red mercury
, various ballotechnics
and others have also been suggested as a means of triggering a pure fusion weapon.
proposed the use of "magnetic pincher fields" to produce pure fusion detonations in his book Protector
.
In the books Domain and Resurrection, by Steve Alten
, bio-mechanical superbirds traveling at super sonic speeds traverse the planet with a pure fusion device nestled in their talons. The devices are photo-reactive, meaning they detonate when sunlight strikes the skin of the superbirds. The devices are so powerful that they vaporize almost 1000 square miles (2,590 km²) of terrain. The devices were placed in locations containing karst
, or calcified lime deposits. The purpose of vaporizing the karst was to raise the global levels of CO2 in an effort to raise global temperature levels
.
Also in Steve Alten's book "Goliath" references are made to pure fusion weapons at a WMD conference, and it is revealed that several world superpowers are trying to develop the devices. Demands are also made to stop all research by the main antagonist, who has hijacked an experimental submarine carrying nuclear weapons
In the video game Metal Gear Solid 2, characters Vamp and Fortune refer to a "purified hydrogen bomb" contained within mobile fortress Arsenal Gear. To quote the former, "this is no ordinary nuclear bomb, this weapon is capable of heavy hydrogen nuclear fusion using lasers and magnetics to generate heat-insulated compression."
Author John Barnes
's book Directive 51
references several pure fusion weapons. The first wave of weapons are built and emplaced as terrorist weapons by humans; a second wave of bombs built by nanomachines on the moon using lunar tritium
are also referenced.
Nuclear weapon design
Nuclear 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...
that does not need a fission
Nuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...
"primary" explosive to ignite the 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...
of deuterium
Deuterium
Deuterium, also called heavy hydrogen, is one of two stable isotopes of hydrogen. It has a natural abundance in Earth's oceans of about one atom in of hydrogen . Deuterium accounts for approximately 0.0156% of all naturally occurring hydrogen in Earth's oceans, while the most common isotope ...
and 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...
, two heavy isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
s of hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
(see Teller-Ulam design
Teller-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,...
for more information about fission-fusion weapons). Such a weapon would require no fissile material and would therefore be much easier to build in secret than existing weapons. The necessity of separating high-quality fissile material requires a substantial industrial investment, and blocking the sale and transfer of the needed machinery has been the primary mechanism to control nuclear proliferation
Nuclear proliferation
Nuclear proliferation is a term now used to describe the spread of nuclear weapons, fissile material, and weapons-applicable nuclear technology and information, to nations which are not recognized as "Nuclear Weapon States" by the Treaty on the Nonproliferation of Nuclear Weapons, also known as the...
to date.
For many years, nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
designers have researched whether it is possible to create high enough temperatures and pressures inside a confined space to fuse together deuterium and tritium for the purposes of developing such a weapon. Pure fusion weapons offer the possibility of generating very small nuclear yields and the advantage of reduced collateral damage stemming from 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...
because these weapons would not create the highly radioactive byproducts associated with fission-type weapons. These weapons would be lethal not only because of their explosive force, which could be large compared to bombs based on chemical explosives, but also because of the neutrons
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...
they generate. The neutrons may cause substantially more casualties than the explosive blast, as in a neutron bomb
Neutron bomb
A neutron bomb or enhanced radiation weapon 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...
.
Despite the many millions of dollars spent by the U.S. between 1952 and 1992 to produce a pure fusion weapon, no measurable success was ever achieved. In 1998, the U.S. Department of Energy (DOE) released a restricted data declassification decision stating that even if the DOE made a substantial investment in the past to develop a pure fusion weapon, "the U.S. Is not known to have and is not developing a pure fusion weapon and no credible design for a pure fusion weapon resulted from the DOE investment". The power densities needed to ignite a fusion reaction still seem attainable only with the aid of a fission explosion, or with large apparatus such as powerful laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
s like those at the National Ignition Facility
National Ignition Facility
The National Ignition Facility, or NIF is a large, laser-based inertial confinement fusion research device located at the Lawrence Livermore National Laboratory in Livermore, California. NIF uses powerful lasers to heat and compress a small amount of hydrogen fuel to the point where nuclear fusion...
, the Sandia Z-pinch machine
Z machine
The Z machine is the largest X-ray generator in the world and is designed to test materials in conditions of extreme temperature and pressure. Operated by Sandia National Laboratories, it gathers data to aid in computer modeling of nuclear weapons...
, or various magnetic tokamak
Tokamak
A tokamak is a device using a magnetic field to confine a plasma in the shape of a torus . Achieving a stable plasma equilibrium requires magnetic field lines that move around the torus in a helical shape...
s. Regardless of any claimed advantages of pure fusion weapons, building those weapons does not appear to be feasible using currently available technologies and many have expressed concern that pure fusion weapons research and development would subvert the intent of the Nuclear Non-Proliferation Treaty
Nuclear Non-Proliferation Treaty
The Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty or NPT, is a landmark international treaty whose objective is to prevent the spread of nuclear weapons and weapons technology, to promote cooperation in the peaceful uses of nuclear energy and to...
and the Comprehensive Test Ban Treaty
Comprehensive Test Ban Treaty
The Comprehensive Nuclear-Test-Ban Treaty bans all nuclear explosions in all environments, for military or civilian purposes. It was adopted by the United Nations General Assembly on 10 September 1996 but it has not entered into force.-Status:...
.
It has been claimed that it is possible to conceive of a crude, deliverable, pure fusion weapon, using only current day, unclassified technology. The weapon design weighs approximately 3 tonnes, and might have a total yield of approximately 3 tonnes of TNT. The proposed design uses a large explosively pumped flux compression generator
Explosively pumped flux compression generator
An explosively pumped flux compression generator is a device used to generate a high-power electromagnetic pulse by compressing magnetic flux using high explosive....
to produce the high power density required to ignite the fusion fuel. From the point of view of explosive damage, such a weapon would have no clear advantages over a conventional explosive, but the massive neutron flux could deliver a lethal dose of radiation to humans within a 500m radius (most of those fatalities would occur over a period of months, rather than immediately).
Some researchers have examined the use of antimatter
Antimatter
In particle physics, antimatter is the extension of the concept of the antiparticle to matter, where antimatter is composed of antiparticles in the same way that normal matter is composed of particles...
as an alternative fusion trigger, mainly in the context of antimatter catalyzed nuclear pulse propulsion
Antimatter catalyzed nuclear pulse propulsion
Antimatter catalyzed nuclear pulse propulsion is a variation of nuclear pulse propulsion based upon the injection of antimatter into a mass of nuclear fuel which normally would not be useful in propulsion...
. Such a system, in a weapons context, would have many of the desired properties of a pure fusion weapon. However, the technical barriers to producing and containing the required quantities of antimatter appear formidable, well beyond present capabilities. Induced gamma emission
Induced gamma emission
In physics, induced gamma emission refers to the process of fluorescent emission of gamma rays from excited nuclei, usually involving a specific nuclear isomer. It is analogous to conventional fluorescence, which is defined as the emission of a photon by an excited electron in an atom or molecule...
is another approach that is currently being researched. Very high energy-density chemicals such as the mythical red mercury
Red mercury
Red mercury is a 19th-century term for protiodide or iodide of mercury. It was commonly recommended for use as an antisyphilitic as late as 1913, most notably during the early years of the Tuskegee Syphilis Experiments. Taken orally, it caused hematemesis...
, various ballotechnics
Ballotechnics
In chemistry, ballotechnics are a class of materials that undergo a chemical reaction when quickly subjected to extreme pressures. These pressures are of the order of tens of thousands of atmospheres, and the chemical reactions are initiated by shock waves transmitted through the material. The...
and others have also been suggested as a means of triggering a pure fusion weapon.
In fiction
Larry NivenLarry Niven
Laurence van Cott Niven / ˈlæri ˈnɪvən/ is an American science fiction author. His best-known work is Ringworld , which received Hugo, Locus, Ditmar, and Nebula awards. His work is primarily hard science fiction, using big science concepts and theoretical physics...
proposed the use of "magnetic pincher fields" to produce pure fusion detonations in his book Protector
Protector (novel)
Protector is a 1973 science fiction novel by Larry Niven, set in his Known Space universe. It was nominated for the Hugo in 1974, and placed fourth in the annual Locus poll for that year....
.
In the books Domain and Resurrection, by Steve Alten
Steve Alten
Steven Robert "Steve" Alten is an American science fiction author. He is best known for his Meg series, a set of novels around the fictitious survival of the megalodon, a giant prehistoric shark...
, bio-mechanical superbirds traveling at super sonic speeds traverse the planet with a pure fusion device nestled in their talons. The devices are photo-reactive, meaning they detonate when sunlight strikes the skin of the superbirds. The devices are so powerful that they vaporize almost 1000 square miles (2,590 km²) of terrain. The devices were placed in locations containing karst
KARST
Kilometer-square Area Radio Synthesis Telescope is a Chinese telescope project to which FAST is a forerunner. KARST is a set of large spherical reflectors on karst landforms, which are bowlshaped limestone sinkholes named after the Kras region in Slovenia and Northern Italy. It will consist of...
, or calcified lime deposits. The purpose of vaporizing the karst was to raise the global levels of CO2 in an effort to raise global temperature levels
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
.
Also in Steve Alten's book "Goliath" references are made to pure fusion weapons at a WMD conference, and it is revealed that several world superpowers are trying to develop the devices. Demands are also made to stop all research by the main antagonist, who has hijacked an experimental submarine carrying nuclear weapons
In the video game Metal Gear Solid 2, characters Vamp and Fortune refer to a "purified hydrogen bomb" contained within mobile fortress Arsenal Gear. To quote the former, "this is no ordinary nuclear bomb, this weapon is capable of heavy hydrogen nuclear fusion using lasers and magnetics to generate heat-insulated compression."
Author John Barnes
John Barnes (author)
-Writing:Two of his novels, The Sky So Big and Black and The Duke of Uranium have been reviewed as having content appropriate for a young adult readership, comparing favorably to Robert A. Heinlein's "juvenile" novels...
's book Directive 51
Directive 51 (book)
Directive 51 is the title of a science fiction novel by John Barnes. It is the first of three books comprising the Daybreak series.- Plot :...
references several pure fusion weapons. The first wave of weapons are built and emplaced as terrorist weapons by humans; a second wave of bombs built by nanomachines on the moon using lunar tritium
Helium-3
Helium-3 is a light, non-radioactive isotope of helium with two protons and one neutron. It is rare on Earth, and is sought for use in nuclear fusion research...
are also referenced.
External links
- "Opening Pandora's nuclear war chest", article on "fourth generation" weapons