Antimatter weapon
Encyclopedia
An antimatter weapon is a hypothetical device using antimatter
as a power source, a propellant
, or an explosive for a weapon
. Antimatter
weapons do not currently exist due to the cost of production and the limited technology available to produce and contain antimatter in sufficient quantities for it to be a useful weapon. The United States Air Force
, however, has been interested in military
uses — including destructive applications — of antimatter since the Cold War
, when it began funding antimatter-related physics
research
. The primary theoretical advantage of such a weapon is that antimatter and matter collisions, though significantly limited by neutrino
losses, still convert a larger fraction of the weapon's mass into explosive energy than a fusion reaction
in a hydrogen bomb, which is on the order of only 0.7%.
On March 24, 2004, Eglin Air Force Base
Munitions Directorate official Kenneth Edwards
spoke at the NASA Institute for Advanced Concepts
http://www.niac.usra.edu/. During the speech, Edwards ostensibly emphasized a potential property of positron
weaponry, a type of antimatter weaponry: Unlike thermonuclear weaponry
, positron weaponry would leave behind "no nuclear residue", such as the nuclear fallout
generated by the nuclear fission
reactions which power nuclear weapons. According to an article in San Francisco Chronicle
, Edwards has granted funding specifically for positron weapons technology development
, focusing research on ways to store positrons for long periods of time
, a significant technical and scientific difficulty.
There is considerable skepticism within the physics community about the viability of antimatter weapons.
According to an article on the website of the CERN
laboratories, which regularly produces antimatter, "There is no possibility to make antimatter bombs for the same reason you cannot use it to store energy: we can't accumulate enough of it at high enough density. (...) If we could assemble all the antimatter we've ever made at CERN and annihilate it with matter, we would have enough energy to light a single electric light bulb for a few minutes."http://public.web.cern.ch/Public/Content/Chapters/Spotlight/SpotlightAandD-en.html
, the equivalent of 42.96 kilotons
of TNT (approximately 3 times the bomb dropped on Hiroshima
- and as such enough to power an average city for an extensive amount of time).
In reality, however, all known technologies for producing antimatter involve particle accelerators, and they are currently still highly inefficient and expensive. The production rate per year is only 1 to 10 nanograms. In 2008, the annual production of antiprotons at the Antiproton Decelerator facility of CERN was several picograms at a cost of $20 million. Thus, at the current level of production, an equivalent of a 10MT
hydrogen bomb, about 250 grams of antimatter will take 2.5 million years of the energy production of the entire Earth to produce. A milligram of antimatter will take 100000 times the annual production rate to produce.(or 100000 years) It will take billions of years for the current production rate to make an equivalent of current typical hydrogen bombs. For example, an equivalent of the Hiroshima atomic bomb
will take half a gram of antimatter, but will take CERN 2 billion years to produce at the current production rate.
Since the first creation of artificial antiprotons in 1955, production rates increased nearly geometrically until the mid-1980s; A significant advancement was made recently as a single anti-hydrogen atom was produced suspended in a magnetic field. Physical laws such as the small cross-section of antiproton production in high-energy nuclear collisions make it difficult and perhaps impossible to drastically improve the production efficiency of antimatter.
Even if it were possible to convert energy directly into particle/antiparticle pairs without any loss, a large-scale power plant generating 2000 MWe
would take 25 hours to produce just one gram of antimatter. Given the average price of electric power around $50 per megawatt hour, this puts a lower limit on the cost of antimatter at $2.5 million per gram. They suggest that this would make antimatter very cost-effective as a rocket fuel, as just one milligram would be enough to send a probe to Pluto
and back in a year, a mission that would be completely unaffordable with conventional fuels. Incidentally the cost of the Manhattan Project
(to produce the first atomic bomb) is estimated at $20 billion in 1996 prices
Most scientists however would doubt whether such efficiencies could ever be achieved.
The second problem is the containment of antimatter. Antimatter annihilates with regular matter on contact, so it would be necessary to prevent contact, for example by producing antimatter in the form of solid charged or magnetized particles, and suspending them using electromagnetic fields in near-perfect vacuum. Another, more hypothetical method is the storage of antiprotons inside fullerenes. The negatively charged antiprotons would repel the electron cloud around the sphere of carbon, so they could not get near enough to the normal protons to annihilate with them.
In order to achieve compactness given macroscopic weight, the overall electric charge of the antimatter weapon core would have to be very small compared to the number of particles. For example, it is not feasible to construct a weapon using positrons alone, due to their mutual repulsion. The antimatter weapon core would have to consist primarily of neutral antiparticles. Extremely small amounts of antihydrogen
have been produced in laboratories, but containing them (by cooling them to temperatures of several millikelvins
and trapping them in a Penning trap
) is extremely difficult. And even if these proposed experiments were successful, they would only trap several antihydrogen atoms for research purposes, far too few for weapons or spacecraft propulsion. Heavier antimatter atoms have yet to be produced.
The difficulty of preventing accidental detonation of an antimatter weapon may be contrasted with that of a nuclear weapon. In an antimatter weapon, any failure of containment would immediately result in energy release, which would probably further damage the containment system and lead to the release of all of the antimatter material, causing the weapon to explode at some very substantial fraction of its full yield. By contrast, a modern nuclear weapon will explode with a significant yield if and only if the chemical explosive triggers are fired at precisely the right sequence at the right time, and a neutron source is triggered at exactly the right time. In short, an antimatter weapon would have to be actively kept from exploding; a nuclear weapon will not explode unless active measures are taken to make it do so.
proposes the use of antimatter as a "trigger" to initiate small nuclear explosions; the explosions provide thrust to a spacecraft. The same technology could theoretically be used to make very small and possibly "fission-free" (very low nuclear fallout
) weapons (see Pure fusion weapon
). Antimatter catalysed weapons could be more discriminate and result in less long-term contamination than conventional nuclear weapons, and their use might therefore be more politically acceptable.
Igniting fusion fuel requires at least a few kilojoules of energy (for laser induced fast ignition of fuel precompressed by a z-pinch), which corresponds to around 10−13 gram of antimatter, or 1011 anti-hydrogen atoms. Fuel compressed by high explosives could be ignited using around 1018 protons to produce a weapon with a one kiloton yield. These quantities are clearly more feasible than those required for "pure" antimatter weapons, but the technical barriers to producing and storing even small amounts of antimatter remain formidable.
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 a power source, a propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...
, or an explosive for a weapon
Weapon
A weapon, arm, or armament is a tool or instrument used with the aim of causing damage or harm to living beings or artificial structures or systems...
. 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...
weapons do not currently exist due to the cost of production and the limited technology available to produce and contain antimatter in sufficient quantities for it to be a useful weapon. The United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
, however, has been interested in military
Military
A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...
uses — including destructive applications — of antimatter since 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...
, when it began funding antimatter-related physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
research
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
. The primary theoretical advantage of such a weapon is that antimatter and matter collisions, though significantly limited by neutrino
Neutrino
A neutrino is an electrically neutral, weakly interacting elementary subatomic particle with a half-integer spin, chirality and a disputed but small non-zero mass. It is able to pass through ordinary matter almost unaffected...
losses, still convert a larger fraction of the weapon's mass into explosive energy than a fusion reaction
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...
in a hydrogen bomb, which is on the order of only 0.7%.
On March 24, 2004, Eglin Air Force Base
Eglin Air Force Base
Eglin Air Force Base is a United States Air Force base located approximately 3 miles southwest of Valparaiso, Florida in Okaloosa County....
Munitions Directorate official Kenneth Edwards
Kenneth Edwards
Kenneth Paine Edwards was an American golfer who competed in the 1904 Summer Olympics.In 1904 he was part of the American team which won the gold medal. He finished fifth in this competition.-External links:...
spoke at the NASA Institute for Advanced Concepts
NASA Institute for Advanced Concepts
right|200pxNASA Institute for Advanced Concepts was a NASA-funded program that was operated by the Universities Space Research Association for NASA from 1998 until its closure on 31 August 2007. NIAC sought proposals for revolutionary aeronautics and space concepts that could dramatically impact...
http://www.niac.usra.edu/. During the speech, Edwards ostensibly emphasized a potential property of positron
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
weaponry, a type of antimatter weaponry: Unlike thermonuclear weaponry
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...
, positron weaponry would leave behind "no nuclear residue", such as the 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...
generated by the nuclear 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...
reactions which power nuclear weapons. According to an article in San Francisco Chronicle
San Francisco Chronicle
thumb|right|upright|The Chronicle Building following the [[1906 San Francisco earthquake|1906 earthquake]] and fireThe San Francisco Chronicle is a newspaper serving primarily the San Francisco Bay Area of the U.S. state of California, but distributed throughout Northern and Central California,...
, Edwards has granted funding specifically for positron weapons technology development
Research and development
The phrase research and development , according to the Organization for Economic Co-operation and Development, refers to "creative work undertaken on a systematic basis in order to increase the stock of knowledge, including knowledge of man, culture and society, and the use of this stock of...
, focusing research on ways to store positrons for long periods of time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
, a significant technical and scientific difficulty.
There is considerable skepticism within the physics community about the viability of antimatter weapons.
According to an article on the website of the CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
laboratories, which regularly produces antimatter, "There is no possibility to make antimatter bombs for the same reason you cannot use it to store energy: we can't accumulate enough of it at high enough density. (...) If we could assemble all the antimatter we've ever made at CERN and annihilate it with matter, we would have enough energy to light a single electric light bulb for a few minutes."http://public.web.cern.ch/Public/Content/Chapters/Spotlight/SpotlightAandD-en.html
Acquiring and storing antimatter
Antimatter production and containment are major obstacles to the creation of antimatter weapons. Quantities measured in grams will be required to achieve destructive effect comparable with conventional nuclear weapons; one gram of antimatter annihilating with one gram of matter produces 180 terajoulesJoule
The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
, the equivalent of 42.96 kilotons
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...
of TNT (approximately 3 times the bomb dropped on Hiroshima
Little boy
Little boy may refer to:* Little Boy, the codename of the atomic bomb dropped on Hiroshima* Little Boy: The Arts of Japan's Exploding Subculture, a book about Japanese postwar culture* Helen Littleboy, documentary director...
- and as such enough to power an average city for an extensive amount of time).
In reality, however, all known technologies for producing antimatter involve particle accelerators, and they are currently still highly inefficient and expensive. The production rate per year is only 1 to 10 nanograms. In 2008, the annual production of antiprotons at the Antiproton Decelerator facility of CERN was several picograms at a cost of $20 million. Thus, at the current level of production, an equivalent of a 10MT
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...
hydrogen bomb, about 250 grams of antimatter will take 2.5 million years of the energy production of the entire Earth to produce. A milligram of antimatter will take 100000 times the annual production rate to produce.(or 100000 years) It will take billions of years for the current production rate to make an equivalent of current typical hydrogen bombs. For example, an equivalent of the Hiroshima atomic bomb
Little Boy
"Little Boy" was the codename of the atomic bomb dropped on Hiroshima on August 6, 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul Tibbets of the 393rd Bombardment Squadron, Heavy, of the United States Army Air Forces. It was the first atomic bomb to be used as a weapon...
will take half a gram of antimatter, but will take CERN 2 billion years to produce at the current production rate.
Since the first creation of artificial antiprotons in 1955, production rates increased nearly geometrically until the mid-1980s; A significant advancement was made recently as a single anti-hydrogen atom was produced suspended in a magnetic field. Physical laws such as the small cross-section of antiproton production in high-energy nuclear collisions make it difficult and perhaps impossible to drastically improve the production efficiency of antimatter.
Even if it were possible to convert energy directly into particle/antiparticle pairs without any loss, a large-scale power plant generating 2000 MWe
MWE
MWE may refer to:*Manufacturer's Weight Empty*McDermott Will & Emery*Midwest Express, an airline*Merowe Airport - IATA code*Multiword expressionMWe may refer to:*Megawatt electrical...
would take 25 hours to produce just one gram of antimatter. Given the average price of electric power around $50 per megawatt hour, this puts a lower limit on the cost of antimatter at $2.5 million per gram. They suggest that this would make antimatter very cost-effective as a rocket fuel, as just one milligram would be enough to send a probe to Pluto
Pluto
Pluto, formal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System and the tenth-most-massive body observed directly orbiting the Sun...
and back in a year, a mission that would be completely unaffordable with conventional fuels. Incidentally the cost of the Manhattan Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...
(to produce the first atomic bomb) is estimated at $20 billion in 1996 prices
Most scientists however would doubt whether such efficiencies could ever be achieved.
The second problem is the containment of antimatter. Antimatter annihilates with regular matter on contact, so it would be necessary to prevent contact, for example by producing antimatter in the form of solid charged or magnetized particles, and suspending them using electromagnetic fields in near-perfect vacuum. Another, more hypothetical method is the storage of antiprotons inside fullerenes. The negatively charged antiprotons would repel the electron cloud around the sphere of carbon, so they could not get near enough to the normal protons to annihilate with them.
In order to achieve compactness given macroscopic weight, the overall electric charge of the antimatter weapon core would have to be very small compared to the number of particles. For example, it is not feasible to construct a weapon using positrons alone, due to their mutual repulsion. The antimatter weapon core would have to consist primarily of neutral antiparticles. Extremely small amounts of antihydrogen
Antihydrogen
Antihydrogen is the antimatter counterpart of hydrogen. Whereas the common hydrogen atom is composed of an electron and proton, the antihydrogen atom is made up of a positron and antiproton...
have been produced in laboratories, but containing them (by cooling them to temperatures of several millikelvins
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
and trapping them in a Penning trap
Penning trap
Penning traps are devices for the storage of charged particles using a homogeneous static magnetic field and a spatially inhomogeneous static electric field. This kind of trap is particularly well suited to precision measurements of properties of ions and stable subatomic particles which have...
) is extremely difficult. And even if these proposed experiments were successful, they would only trap several antihydrogen atoms for research purposes, far too few for weapons or spacecraft propulsion. Heavier antimatter atoms have yet to be produced.
The difficulty of preventing accidental detonation of an antimatter weapon may be contrasted with that of a nuclear weapon. In an antimatter weapon, any failure of containment would immediately result in energy release, which would probably further damage the containment system and lead to the release of all of the antimatter material, causing the weapon to explode at some very substantial fraction of its full yield. By contrast, a modern nuclear weapon will explode with a significant yield if and only if the chemical explosive triggers are fired at precisely the right sequence at the right time, and a neutron source is triggered at exactly the right time. In short, an antimatter weapon would have to be actively kept from exploding; a nuclear weapon will not explode unless active measures are taken to make it do so.
Antimatter catalyzed weapons
Antimatter catalyzed nuclear pulse propulsionAntimatter 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...
proposes the use of antimatter as a "trigger" to initiate small nuclear explosions; the explosions provide thrust to a spacecraft. The same technology could theoretically be used to make very small and possibly "fission-free" (very low 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...
) weapons (see Pure fusion weapon
Pure fusion weapon
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 isotopes of hydrogen . Such a weapon would require no fissile material and would therefore be much easier to build in secret than...
). Antimatter catalysed weapons could be more discriminate and result in less long-term contamination than conventional nuclear weapons, and their use might therefore be more politically acceptable.
Igniting fusion fuel requires at least a few kilojoules of energy (for laser induced fast ignition of fuel precompressed by a z-pinch), which corresponds to around 10−13 gram of antimatter, or 1011 anti-hydrogen atoms. Fuel compressed by high explosives could be ignited using around 1018 protons to produce a weapon with a one kiloton yield. These quantities are clearly more feasible than those required for "pure" antimatter weapons, but the technical barriers to producing and storing even small amounts of antimatter remain formidable.
External links
- Spotlight on "Angels and Demons" A discussion at CERN's public website on the viability of the use of antimatter for energy and weaponry.
- "Air Force pursuing antimatter weapons: Program was touted publicly, then came official gag order"
- Page discussing the possibility of using antimatter as a trigger for a thermonuclear explosion
- Paper discussing the number of antiprotons required to ignite a thermonuclear weapon.