Fusion power refers to power generated by nuclear fusion reactions. In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus In this kind of reaction, two light atomic nuclei fuse together to form a heavier nucleus and in doing so, release energy. The nucleus of an Atom is the very dense region consisting of Nucleons ( Protons and Neutrons, at the center of an atom In a more general sense, the term can also refer to the production of net usable power from a fusion source, similar to the usage of the term "steam power. " Most design studies for fusion power plants involve using the fusion reactions to create heat, which is then used to operate a steam turbine, similar to most coal-fired power stations as well as fission-driven nuclear power stations. A steam turbine is a mechanical device that extracts Thermal energy from pressurized Steam, and converts it into useful mechanical work Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing Free neutrons and other smaller nuclei which may Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions
The largest current experiment is the Joint European Torus [JET]. JET, the Joint European Torus, is the largest Nuclear fusion experimental reactor yet built In 1997, JET produced a peak of 16. 1 MW of fusion power (65% of input power), with fusion power of over 10 MW sustained for over 0. The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. 5 sec. In June 2005, the construction of the experimental reactor ITER, designed to produce several times more fusion power than the power put into the plasma over many minutes, was announced. ITER is an international Tokamak ( Magnetic confinement fusion) research/engineering proposal for an experimental project that will help to make the transition from The production of net electrical power from fusion is planned for DEMO, the next generation experiment after ITER. DEMO (DEMOnstration Power Plant is a proposed Nuclear fusion power plant that is intended to build upon the expected success of the ITER (originally
The basic concept behind any fusion reaction is to bring two or more atoms very close together, close enough that the strong nuclear force in their nuclei will pull them together into one larger atom. In particle physics the strong interaction, or strong force, or color force, holds Quarks and Gluons together to form Protons and If two light nuclei fuse, they will generally form a single nucleus with a slightly smaller mass than the sum of their original masses. The difference in mass is released as energy according to Einstein's mass-energy equivalence formula E = mc². In Physics, mass–energy equivalence is the concept that for particles slower than light any Mass has an associated Energy and vice versa. If the input atoms are sufficiently massive, the resulting fusion product will be heavier than the reactants, in which case the reaction requires an external source of energy. The dividing line between "light" and "heavy" is iron. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Above this atomic mass, energy will generally be released in nuclear fission reactions, below it, in fusion. Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing Free neutrons and other smaller nuclei which may
Fusion between the atoms is opposed by their shared electrical charge, specifically the net positive charge of the nuclei. In order to overcome this electrostatic force, or "Coulomb barrier", some external source of energy must be supplied. ---- Bold text Coulomb's law', developed in the 1780s by French physicist Charles Augustin de Coulomb, may be stated in scalar form The Coulomb barrier, named after physicist Charles-Augustin de Coulomb (1736&ndash1806 is the energy barrier due to Electrostatic interaction that two nuclei need The easiest way to do this is to heat the atoms, which has the side effect of stripping the electrons from the atoms and leaving them as bare nuclei. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J In most experiments the nuclei and electrons are left in a fluid known as a plasma. In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound The temperatures required to provide the nuclei with enough energy to overcome their repulsion is a function of the total charge, so hydrogen, which has the smallest nuclear charge therefore reacts at the lowest temperature. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Helium has an extremely low mass per nucleon and therefore is energetically favoured as a fusion product. Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical As a consequence, most fusion reactions combine isotopes of hydrogen ("protium", deuterium, or tritium) to form isotopes of helium (³He or 4He). In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus A hydrogen atom is an atom of the chemical element Hydrogen. The electrically neutral Deuterium, also called heavy hydrogen, is a Stable isotope of Hydrogen with a Natural abundance in the Oceans of Earth Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen.
Perhaps the three most widely considered fuel cycles are based on the D-T, D-D, and p-11B reactions. Other fuel cycles (D-³He and ³He-³He) would require a supply of ³He, either from other nuclear reactions or from extraterrestrial sources, such as the surface of the moon or the atmospheres of the gas giant planets. The details of the calculations comparing these reactions can be found here. In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus
The easiest (according to the Lawson criterion) and most immediately promising nuclear reaction to be used for fusion power is:
Deuterium is a naturally occurring isotope of hydrogen and as such is universally available. In Nuclear fusion research the Lawson criterion, first derived by John D Deuterium, also called heavy hydrogen, is a Stable isotope of Hydrogen with a Natural abundance in the Oceans of Earth Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen. Helium-4 ( or) is a non- Radioactive and light Isotope of Helium. This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides The large mass ratio of the hydrogen isotopes makes the separation rather easy compared to the difficult uranium enrichment process. Enriched uranium is a kind of Uranium in which the percent composition of Uranium-235 has been increased through the process of Isotope separation. Tritium is also an isotope of hydrogen, but it occurs naturally in only negligible amounts due to its radioactive half-life of 12. In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted Half-Life (computer-game page here It's already listed in the disambiguation page 32 years. Consequently, the deuterium-tritium fuel cycle requires the breeding of tritium from lithium using one of the following reactions:
The reactant neutron is supplied by the D-T fusion reaction shown above, the one which also produces the useful energy. A breeder reactor is a Nuclear reactor that generates new Fissile or fissionable material at a greater rate than it consumes such material Lithium (ˈlɪθiəm is a Chemical element with the symbol Li and Atomic number 3 The reaction with 6Li is exothermic, providing a small energy gain for the reactor. An exothermic reaction is a Chemical reaction that releases Heat. The reaction with 7Li is endothermic but does not consume the neutron. In Thermodynamics, the word endothermic "within-heating" describes a process or reaction that absorbs Energy in the form of Heat. At least some 7Li reactions are required to replace the neutrons lost by reactions with other elements. Most reactor designs use the naturally occurring mix of lithium isotopes. The supply of lithium is more limited than that of deuterium, but still large enough to supply the world's energy demand for thousands of years.
Several drawbacks are commonly attributed to D-T fusion power:
The neutron flux expected in a commercial D-T fusion reactor is about 100 times that of current fission power reactors, posing problems for material design. Neutron flux is a term referring to the number of Neutrons passing through an Area over a span of Time. Design of suitable materials is underway but their actual use in a reactor is not proposed until the generation after ITER. ITER is an international Tokamak ( Magnetic confinement fusion) research/engineering proposal for an experimental project that will help to make the transition from After a single series of D-T tests at JET, the largest fusion reactor yet to use this fuel, the vacuum vessel was sufficiently radioactive that remote handling needed to be used for the year following the tests. JET, the Joint European Torus, is the largest Nuclear fusion experimental reactor yet built
On the other hand, the volumetric deposition of neutron power can also be seen as an advantage. If all the power of a fusion reactor had to be transported by conduction through the surface enclosing the plasma, it would be very difficult to find materials and a construction that would survive, and it would probably entail a relatively poor efficiency.
Though more difficult to facilitate than the deuterium-tritium reaction, fusion can also be achieved through the reaction of deuterium with itself. This reaction has two branches that occur with nearly equal probability:
|D + D||→ T||+ p|
|→ ³He||+ n|
The optimum temperature for this reaction is 15 keV, only slightly higher than the optimum for the D-T reaction. The first branch does not produce neutrons, but it does produce tritium, so that a D-D reactor will not be completely tritium-free, even though it does not require an input of tritium or lithium. Most of the tritium produced will be burned before leaving the reactor, which reduces the tritium handling required, but also means that more neutrons are produced and that some of these are very energetic. The neutron from the second branch has an energy of only 2. 45 MeV, whereas the neutron from the D-T reaction has an energy of 14. 1 MeV, resulting in a wider range of isotope production and material damage. Assuming complete tritium burn-up, the reduction in the fraction of fusion energy carried by neutrons is only about 18%, so that the primary advantage of the D-D fuel cycle is that tritium breeding is not required. Other advantages are independence from limitations of lithium resources and a somewhat softer neutron spectrum. The price to pay compared to D-T is that the energy confinement (at a given pressure) must be 30 times better and the power produced (at a given pressure and volume) is 68 times less.
If aneutronic fusion is the goal, then the most promising candidate may be the proton-boron reaction:
Under reasonable assumptions, side reactions will result in about 0. Aneutronic fusion is any form of Fusion power where no more than 1% of the total energy released is carried by Neutrons Since the most-studied fusion reactions 1% of the fusion power being carried by neutrons. At 123 keV, the optimum temperature for this reaction is nearly ten times higher than that for the pure hydrogen reactions, the energy confinement must be 500 times better than that required for the D-T reaction, and the power density will be 2500 times lower than for D-T. In Engineering, the term specific power can refer to power either per unit of Mass, Volume or Area, although power per unit of Since the confinement properties of conventional approaches to fusion such as the tokamak and laser pellet fusion are marginal, most proposals for aneutronic fusion are based on radically different confinement concepts.
The idea of using human-initiated fusion reactions was first made practical for military purposes, in nuclear weapons. A nuclear weapon is an explosive device that derives its destructive force from Nuclear reactions either fission or a combination of fission and fusion. In a hydrogen bomb, the energy released by a fission weapon is used to compress and heat fusion fuel, beginning a fusion reaction which can release a very large amount of energy. The first fusion-based weapons released some 500 times more energy than early fission weapons.
Civilian applications, in which explosive energy production must be replaced by a controlled production, are still being developed. Although it took less than ten years to go from military applications to civilian fission energy production, it has been very different in the fusion energy field; more than fifty years have already passed without any commercial fusion energy production plant coming into operation.
Registration of the first patent related to a fusion reactor by the United Kingdom Atomic Energy Authority, the inventors being Sir George Paget Thomson and Moses Blackman, dates back to 1946. The United Kingdom Atomic Energy Authority (UKAEA was established in 1954 as a Statutory corporation to oversee and pioneer the development of Nuclear energy within Sir George Paget Thomson, FRS ( May 3, 1892 &ndash September 10, 1975) was an English Physicist and Moses Blackman ( December 6, 1908 - June 3, 1983) was a South African born British crystallographer. Some basic principles used in the ITER experiment are described in this patent: toroidal vacuum chamber, magnetic confinement, and radio frequency plasma heating. Radio frequency ( RF) is a Frequency or rate of Oscillation within the range of about 3 Hz to 300 GHz
The U. S. fusion program began in 1951 when Lyman Spitzer began work on a stellarator under the code name Project Matterhorn. Lyman Strong Spitzer Jr ( June 26, 1914 &ndash March 31, 1997) was an American theoretical physicist. A stellarator is a device used to confine a hot plasma with magnetic fields in order to sustain a controlled Nuclear fusion reaction His work led to the creation of the Princeton Plasma Physics Laboratory, where magnetically confined plasmas are still studied. Princeton Plasma Physics Laboratory (PPPL is a United States Department of Energy national laboratory for Plasma physics and Nuclear fusion The stellarator concept fell out of favor for several decades afterwards, plagued by poor confinement issues, but recent advances in computer technology have led to a significant resurgence in interest in these devices. A stellarator is a device used to confine a hot plasma with magnetic fields in order to sustain a controlled Nuclear fusion reaction A wide variety of other magnetic geometries were also experimented with, notably with the magnetic mirror. A magnetic mirror is a Magnetic field configuration where the field strength changes when moving along a field line These systems also suffered from similar problems when higher performance versions were constructed.
A new approach was outlined in the theoretical works fulfilled in 1950–1951 by I.E. Tamm and A.D. Sakharov in Soviet Union, which laid the foundations of the tokamak. Igor Yevgenyevich Tamm ( Russian И́горь Евге́ньевич Та́мм) ( July 8 1895 &ndash April 12 1971) was Andrei Dmitrievich Sakharov (Андре́й Дми́триевич Са́харов (May 21 1921 – December 14 1989 was an eminent Soviet nuclear Physicist The Union of Soviet Socialist Republics (USSR was a constitutionally Socialist state that existed in Eurasia from 1922 to 1991 A tokamak is a machine producing a toroidal Magnetic field for confining a plasma. Experimental research of these systems started in 1956 in Kurchatov Institute, Moscow by a group of Soviet scientists lead by Lev Artsimovich. Kurchatov Institute ( Роcсийский научный центр "Курчатовский Институт" Russian Scientific Centre "Kurchatov Institute" is Moscow (Москва́ romanised: Moskvá, IPA: see also other names) is the Capital and the largest city of Lev Andreevich Artsimovich ( Арцимович Лев Андреевич in Russian; also transliterated Arzimowitsch) ( 25 February The group constructed the first tokamaks, the most successful of them being T-3 and its larger version T-4. T-4 was tested in 1968 in Novosibirsk, conducting the first quasistationary thermonuclear fusion reaction ever. History The city was founded in 1893 as the future site of the Trans-Siberian Railway bridge crossing the great Siberian river Ob, and was known as  The tokamak was dramatically more efficient than the other approaches of the same era, and most research after the 1970s concentrated on variations of this theme.
The same is true today, where very large tokamaks like ITER are hoping to demonstrate several milestones on the way to commercial power production, including a burning plasma with long burn times, high power output and online fueling. ITER is an international Tokamak ( Magnetic confinement fusion) research/engineering proposal for an experimental project that will help to make the transition from The fusion energy gain factor, usually expressed with the symbol Q, is the ratio of Fusion power produced in a Nuclear fusion reactor to the power required There are no guarantees that the project will be successful, as previous generations of machines have faced formerly unseen problems on many occasions. But the entire field of high temperature plasmas is much better understood now due to the earlier research, and there is considerable optimism that ITER will meet its goals. If successful, ITER would be followed by a "commercial demonstrator" system, similar to the very earliest power-producing fission reactors built in the era before wide-scale commercial deployment of larger machines started in the 1960s and 1970s. Even with these goals met, there are a number of major engineering problems remaining, notably finding suitable "low activity" materials for reactor construction, demonstrating secondary systems including practical tritium extraction, and building reactor designs that allow their reactor core to be removed when it becomes embrittled due to the neutron flux. Practical generators based on the tokamak concept remain far in the future. The public at large has been somewhat disappointed, as the initial outlook for practical fusion power plants was much rosier than is now realized; a pamphlet from the 1970s printed by General Atomic stated that "Several commercial fusion reactors are expected to be online by the year 2000. "
The Z-pinch phenomenon has been known since the end of the 18th century. In Fusion power research the Z-pinch, or zeta pinch, is a type of plasma confinement system that uses an electrical current in the plasma to generate The 18th century lasted from 1701 to 1800 in the Gregorian calendar, in accordance with the Anno Domini / Common Era numbering system  Its use in the fusion field comes from research made on toroidal devices, initially in the Los Alamos National Laboratory right from 1952 (Perhapsatron), and in the United Kingdom from 1954 (ZETA), but its physical principles remained for a long time poorly understood and controlled. Los Alamos National Laboratory (LANL (previously known at various times as Site Y, Los Alamos Laboratory, and Los Alamos Scientific Laboratory) is a Year 1952 ( MCMLII) was a Leap year starting on Tuesday (link will display full calendar of the Gregorian calendar. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Year 1954 ( MCMLIV) was a Common year starting on Friday (link will display full 1954 Gregorian calendar) Pinch devices were studied as potential development paths to practical fusion devices through the 1950s, but studies of the data generated by these devices suggested that instabilities in the collapse mechanism would doom any pinch-type device to power levels that were far too low to suggest continuing along these lines would be practical. Most work on pinch-type devices ended by the 1960s. Recent work on the basic concept started as a result of the appearance of the "wires array" concept in the 1980s, which allowed a more efficient use of this technique. The Sandia National Laboratory runs a continuing wire-array research program with the Zpinch 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 In addition, the University of Washington's ZaP Lab have shown quiescent periods of stability hundreds of times longer than expected for plasma in a Z-pinch configuration, giving promise to the confinement technique. See Washington (disambiguation for other uses The University of Washington, founded in 1861, is a public research University
The technique of implosion of a microcapsule irradiated by laser beams, the basis of laser inertial confinement, was first suggested in 1962 by scientists at Lawrence Livermore National Laboratory, shortly after the invention of the laser itself in 1960. A laser is a device that emits Light ( Electromagnetic radiation) through a process called Stimulated emission. Inertial confinement fusion ( ICF) is a process where Nuclear fusion reactions are initiated by heating and compressing a fuel target typically in the form of The Lawrence Livermore National Laboratory ( LLNL) in Livermore California is a scientific research laboratory founded by the University of California in 1952 Lasers of the era were very low powered, but low-level research using them nevertheless started as early as 1965. More serious research started in the early 1970s when new types of lasers offered a path to dramatically higher power levels, levels that made inertial-confinement fusion devices appear practical for the first time. By the late 1970s great strides had been made in laser power, but with each increase new problems were found in the implosion technique that suggested even more power would be required. By the 1980s these increases were so large that using the concept for generating net energy seemed remote. Most research in this field turned to weapons research, always a second line of research, as the implosion concept is somewhat similar to hydrogen bomb operation. The Teller–Ulam design is a Nuclear weapon design which is used in Megaton -range Thermonuclear weapons and is more colloquially referred to as "the Work on very large versions continued as a result, with the very large National Ignition Facility in the US and Laser Mégajoule in France supporting these research programs. The National Ignition Facility, or NIF, is a Laser -based Inertial confinement fusion (ICF research device under construction at the Lawrence Laser Mégajoule ( LMJ) is an experimental Inertial confinement fusion (ICF device being built in France by the French nuclear science directorate
More recent work had demonstrated that significant savings in the required laser energy are possible using a technique known as "fast ignition". The savings are so dramatic that the concept appears to be a useful technique for energy production again, so much so that it is a serious contender for pre-commercial development once again. There are proposals to build an experimental facility dedicated to the fast ignition approach, known as HiPER. The High Power laser Energy Research facility ( HiPER) is an experimental laser-driven Inertial confinement fusion (ICF device undergoing preliminary design for possible At the same time, advances in solid state lasers appear to improve the "driver" systems' efficiency by about ten times (to 10- 20%), savings that make even the large "traditional" machines almost practical, and might make the fast ignition concept outpace the magnetic approaches in further development. A solid-state laser is a Laser that uses a gain medium that is a Solid, rather than a Liquid such as in Dye lasers or a Gas The laser-based concept has other advantages as well. The reactor core is mostly exposed, as opposed to being wrapped in a huge magnet as in the tokamak. This makes the problem of removing energy from the system somewhat simpler, and should mean that a laser-based device would be much easier to perform maintenance on, such as core replacement. Additionally, the lack of strong magnetic fields allows for a wider variety of low-activation materials, including carbon fiber, which would both reduce the frequency of such swaps, as well as reducing the radioactivity of the discarded core. In other ways the program has many of the same problems as the tokamak; practical methods of energy removal and tritium recycling need to be demonstrated, and in addition there is always the possibility that a new previously unseen collapse problem will arise.
Throughout the history of fusion power research there have been a number of devices that have produced fusion at a much smaller level, not being suitable for energy production, but nevertheless starting to fill other roles.
Inventor of the Cathode Ray Tube Television Philo T. Farnsworth patented his first Fusor design in 1968, a device which uses inertial electrostatic confinement. The cathode ray tube (CRT is a Vacuum tube containing an Electron gun (a source of electrons and a Fluorescent screen with internal or Philo Taylor Farnsworth ( August 19, 1906 – March 11, 1971) was an American inventor The Farnsworth–Hirsch Fusor, or simply fusor, is an apparatus designed by Philo T Inertial electrostatic confinement (often abbreviated as IEC) is a concept for retaining a plasma using an electrostatic field Towards the end of the 1960s, Robert Hirsch designed a variant of the Farnsworth Fusor known as the Hirsch-Meeks fusor. See also Hirsch report Dr Robert L Hirsch is a former senior Energy program adviser for Science Applications International Corporation The Farnsworth–Hirsch Fusor, or simply fusor, is an apparatus designed by Philo T This variant is a considerable improvement over the Farnsworth design, and is able to generate neutron flux in the order of one billion neutrons per second. Although the efficiency was very low at first, there were hopes the device could be scaled up, but continued development demonstrated that this approach would be impractical for large machines. Nevertheless, fusion could be achieved using a "lab bench top" type set up for the first time, at minimal cost. This type of fusor found its first application as a portable neutron generator in the late 1990s. Neutron generators are Neutron source devices which contain compact Linear accelerators and that produce Neutrons by fusing Isotopes of Hydrogen An automated sealed reaction chamber version of this device, commercially named Fusionstar was developed by EADS but abandoned in 2001. The European Aeronautic Defence and Space Company EADS NV ( EADS) is a large European aerospace corporation formed by the merger on July 10, Its successor is the NSD-Fusion neutron generator. Neutron generators are Neutron source devices which contain compact Linear accelerators and that produce Neutrons by fusing Isotopes of Hydrogen
Robert W. Bussard's Polywell concept is roughly similar to the Fusor design, but replaces the problematic grid with a magnetically contained electron cloud which holds the ions in position and gives an accelerating potential. Robert W Bussard ( August 11 1928 &ndash October 6 2007) was an American Physicist who worked primarily in Nuclear The polywell is a plasma confinement concept that combines elements of Inertial electrostatic confinement and Magnetic confinement fusion, intended The Farnsworth–Hirsch Fusor, or simply fusor, is an apparatus designed by Philo T Bussard claimed that a scaled up version would be capable of generating net power.
In April 2005, a team from UCLA announced it had devised a novel way of producing fusion using a machine that "fits on a lab bench", using lithium tantalate to generate enough voltage to smash deuterium atoms together. The University of California Los Angeles (generally known as UCLA) is a public research university located in Westwood Los Angeles, California, United Lithium tantalate (LiTaO3 is a crystalline solid which possesses unique Optical, Piezoelectric and Pyroelectric properties which make it valuable However, the process does not generate net power. See Pyroelectric fusion. Pyroelectric fusion refers to the technique of using pyroelectric Crystals Such a device would be useful in the same sort of roles as the fusor.
The likelihood of a catastrophic accident in a fusion reactor in which injury or loss of life occurs is much smaller than that of a fission reactor. This article is a subarticle of Nuclear power. A nuclear reactor is a device in which Nuclear chain reactions are initiated controlled The primary reason is that the fission products in a fission reactor continue to generate heat through beta-decay for several hours or even days after reactor shut-down, meaning that a meltdown is plausible even after the reactor has been stopped. In contrast, fusion requires precisely controlled conditions of temperature, pressure and magnetic field parameters in order to generate net energy. If the reactor were damaged, these parameters would be disrupted and the heat generation in the reactor would rapidly cease.
There is also no risk of a runaway reaction in a fusion reactor, since the plasma is normally burnt at optimal conditions, and any significant change will render it unable to produce excess heat. Runaway reactions are also less of a concern in modern fission reactors, as they are typically designed to immediately shut down under accident conditions, but in a fusion reactor such behaviour is almost unavoidable, and there is thus little need to carefully design them to achieve this extra safety feature. Although the plasma in a fusion power plant will have a volume of 1000 cubic meters or more, the density of the plasma is extremely low, and the total amount of fusion fuel in the vessel is very small, typically a few grams. If the fuel supply is closed, the reaction stops within seconds. In comparison, a fission reactor is typically loaded with enough fuel for one or several years, and no additional fuel is necessary to keep the reaction going.
In the magnetic approach, strong fields are developed in coils that are held in place mechanically by the reactor structure. Failure of this structure could release this tension and allow the magnet to "explode" outward. The severity of this event would be similar to any other industrial accident, and could be effectively stopped with a containment building similar to those used in existing (fission) nuclear generators. A containment building, in its most common usage is a Steel or reinforced concrete structure enclosing a Nuclear reactor. The laser-driven inertial approach is generally lower-stress. Although failure of the reaction chamber is possible, simply stopping fuel delivery would prevent any sort of catastrophic failure.
Most reactor designs rely on the use of liquid lithium as both a coolant and a method for converting stray neutrons from the reaction into tritium, which is fed back into the reactor as fuel. Lithium (ˈlɪθiəm is a Chemical element with the symbol Li and Atomic number 3 Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen. Lithium is highly flammable, and in the case of a fire it is possible that the lithium stored on-site could be burned up and escape. In this case the tritium contents of the lithium would be released into the atmosphere, posing a radiation risk. However, calculations suggest that the total amount of tritium and other radioactive gases in a typical power plant would be so small, about 1 kg, that they would have diluted to legally acceptable limits by the time they blew as far as the plant's perimeter fence. A perimeter fence is a structure that circles the Perimeter of an area to prevent access
The natural product of the fusion reaction is a small amount of helium, which is completely harmless to life and does not contribute to global warming. Global warming is the increase in the average measured temperature of the Of more concern is tritium, which, like other isotopes of hydrogen, is difficult to retain completely. Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen. During normal operation, some amount of tritium will be continually released. There would be no acute danger, but the cumulative effect on the world's population from a fusion economy could be a matter of concern. The 12 year half-life of tritium would at least prevent unlimited build-up and long-term contamination without appropriate containment techniques. Current ITER designs are investigating total containment facilities for any tritium.
The large flux of high-energy neutrons in a reactor will make the structural materials radioactive. The radioactive inventory at shut-down may be comparable to that of a fission reactor, but there are important differences.
The half-life of the radioisotopes produced by fusion tend to be less than those from fission, so that the inventory decreases more rapidly. A radionuclide is an Atom with an unstable nucleus, which is a nucleus characterized by excess energy which is available to be imparted either to a newly-created Furthermore, there are fewer unique species, and they tend to be non-volatile and biologically less active. Unlike fission reactors, whose waste remains dangerous for thousands of years, most of the radioactive material in a fusion reactor would be the reactor core itself, which would be dangerous for about 50 years, and low-level waste another 100. By 300 years the material would have the same radioactivity as coal ash. Fly ash is one of the residues generated in the Combustion of Coal. . In current designs, some materials will yield waste products with long half-lives. 
Additionally, the materials used in a fusion reactor are more "flexible" than in a fission design, where many materials are required for their specific neutron cross-sections. This allows a fusion reactor to be designed using materials that are selected specifically to be "low activation", materials that do not easily become radioactive. Vanadium, for example, would become much less radioactive than stainless steel. Vanadium (vəˈneɪdiəm is a Chemical element that has the symbol V and Atomic number 23 In Metallurgy, stainless steel is defined as a Steel Alloy with a minimum of 11 Carbon fibre materials are also low-activation, as well as being strong and light, and are a promising area of study for laser-inertial reactors where a magnetic field is not required.
In general terms, fusion reactors would create far less radioactive material than a fission reactor, the material it would create is less damaging biologically, and the radioactivity "burns off" within a time period that is well within existing engineering capabilities.
Although fusion power uses nuclear technology, the overlap with nuclear weapons technology is small. Tritium is a component of the trigger of hydrogen bombs, but not a major problem in production. Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen. The Teller–Ulam design is a Nuclear weapon design which is used in Megaton -range Thermonuclear weapons and is more colloquially referred to as "the The copious neutrons from a fusion reactor could be used to breed plutonium for an atomic bomb, but not without extensive redesign of the reactor, so that clandestine production would be easy to detect. The theoretical and computational tools needed for hydrogen bomb design are closely related to those needed for inertial confinement fusion, but have very little in common with (the more scientifically developed) magnetic confinement fusion. Inertial confinement fusion ( ICF) is a process where Nuclear fusion reactions are initiated by heating and compressing a fuel target typically in the form of Magnetic confinement fusion is an approach to generating Fusion energy that uses Magnetic fields to confine the fusion fuel in the form of a plasma.
Large-scale reactors using neutronic fuels (e. g. ITER) and thermal power production (turbine based) are most comparable to fission power from an engineering and economics viewpoint. ITER is an international Tokamak ( Magnetic confinement fusion) research/engineering proposal for an experimental project that will help to make the transition from Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions Both fission and fusion power plants involve a relatively compact heat source powering a conventional steam turbine-based power plant, while producing enough neutron radiation to make activation of the plant materials problematic. Neutron activation is the process in which Neutron radiation induces Radioactivity in materials and occurs when atomic nuclei capture Free neutrons The main distinction is that fusion power produces no high-level radioactive waste (though activated plant materials still need to be disposed of). There are some power plant ideas which may significantly lower the cost or size of such plants; however, research in these areas is nowhere near as advanced as in tokamaks. A tokamak is a machine producing a toroidal Magnetic field for confining a plasma.
Fusion power commonly proposes the use of deuterium, an isotope of hydrogen, as fuel and in many current designs also use lithium. Deuterium, also called heavy hydrogen, is a Stable isotope of Hydrogen with a Natural abundance in the Oceans of Earth Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides Lithium (ˈlɪθiəm is a Chemical element with the symbol Li and Atomic number 3 Assuming a fusion energy output equal to the current global output and that this does not increase in the future, then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years. 
Confinement refers to all the conditions necessary to keep a plasma dense and hot long enough to undergo fusion:
The first human-made, large-scale production of fusion reactions was the test of the hydrogen bomb, Ivy Mike, in 1952 . The Teller–Ulam design is a Nuclear weapon design which is used in Megaton -range Thermonuclear weapons and is more colloquially referred to as "the Ivy Mike was the codename given to the first US test of a fusion device where a major part of the explosive yield came from fusion It was once proposed to use hydrogen bombs as a source of power by detonating them in underground caverns and then generating electricity from the heat produced, but such a power plant is unlikely ever to be constructed, for a variety of reasons. (See the PACER project for more details. The PACER project carried out at Los Alamos National Laboratory in the mid-1970s explored the possibility of a Fusion power system that would involve exploding small ) Controlled thermonuclear fusion (CTF) refers to the alternative of continuous power production, or at least the use of explosions that are so small that they do not destroy a significant portion of the machine that produces them.
To produce self-sustaining fusion, the energy released by the reaction (or at least a fraction of it) must be used to heat new reactant nuclei and keep them hot long enough that they also undergo fusion reactions. Retaining the heat is called energy confinement and may be accomplished in a number of ways.
The hydrogen bomb really has no confinement at all. The fuel is simply allowed to fly apart, but it takes a certain length of time to do this, and during this time fusion can occur. This approach is called inertial confinement. Inertial confinement fusion ( ICF) is a process where Nuclear fusion reactions are initiated by heating and compressing a fuel target typically in the form of If more than milligram quantities of fuel are used (and efficiently fused), the explosion would destroy the machine, so theoretically, controlled thermonuclear fusion using inertial confinement would be done using tiny pellets of fuel which explode several times a second. To induce the explosion, the pellet must be compressed to about 30 times solid density with energetic beams. If the beams are focused directly on the pellet, it is called direct drive, which can in principle be very efficient, but in practice it is difficult to obtain the needed uniformity. An alternative approach is indirect drive, in which the beams heat a shell, and the shell radiates x-rays, which then implode the pellet. X-radiation (composed of X-rays) is a form of Electromagnetic radiation. The beams are commonly laser beams, but heavy and light ion beams and electron beams have all been investigated. An ion beam is a type of Particle beam consisting of Ions. Ion beams have many uses in Electronics manufacturing (principally Ion implantation
Inertial confinement produces plasmas with impressively high densities and temperatures, and appears to be best suited to weapons research, X-ray generation, very small reactors, and perhaps in the distant future, spaceflight. They rely on fuel pellets with close to a "perfect" shape in order to generate a symmetrical inward shock wave to produce the high-density plasma, and in practice these have proven difficult to produce. For the music album by Converter see Shock Front For the 1977 horror film see Shock Waves A shock wave (also called A recent development in the field of laser induced ICF is the use of ultrashort pulse multi-petawatt lasers to heat the plasma of an imploding pellet at exactly the moment of greatest density after it is imploded conventionally using terawatt scale lasers. This page lists examples of the power in Watts produced by various different sources of energy This research will be carried out on the (currently being built) OMEGA EP petawatt and OMEGA lasers at the University of Rochester and at the GEKKO XII laser at the institute for laser engineering in Osaka Japan, which if fruitful, may have the effect of greatly reducing the cost of a laser fusion based power source. The University of Rochester ( U of R UR) is a private, nonsectarian Coeducational Research University located in Rochester
At the temperatures required for fusion, the fuel is in the form of a plasma with very good electrical conductivity. Electrical conductivity or specific conductivity is a measure of a material's ability to conduct an Electric current. This opens the possibility to confine the fuel and the energy with magnetic fields, an idea known as magnetic confinement. In Physics, a magnetic field is a Vector field that permeates space and which can exert a magnetic force on moving Electric charges Magnetic confinement fusion is an approach to generating Fusion energy that uses Magnetic fields to confine the fusion fuel in the form of a plasma. The Lorenz force works only perpendicular to the magnetic field, so that the first problem is how to prevent the plasma from leaking out the ends of the field lines. In Physics, the Lorentz force is the Force on a Point charge due to Electromagnetic fields It is given by the following equation There are basically two solutions.
The first is to use the magnetic mirror effect. A magnetic mirror is a Magnetic field configuration where the field strength changes when moving along a field line If particles following a field line encounter a region of higher field strength, then some of the particles will be stopped and reflected. Advantages of a magnetic mirror power plant would be simplified construction and maintenance due to a linear topology and the potential to apply direct conversion in a natural way, but the confinement achieved in the experiments was so poor that this approach has been essentially abandoned.
The second possibility to prevent end losses is to bend the field lines back on themselves, either in circles or more commonly in nested toroidal surfaces. In Geometry, a torus (pl tori) is a Surface of revolution generated by revolving a Circle in three dimensional space about an axis Coplanar The most highly developed system of this type is the tokamak, with the stellarator being next most advanced, followed by the Reversed field pinch. A tokamak is a machine producing a toroidal Magnetic field for confining a plasma. A stellarator is a device used to confine a hot plasma with magnetic fields in order to sustain a controlled Nuclear fusion reaction A reversed-field pinch (RFP is a device used to produce and contain near-thermonuclear plasmas. Compact toroids, especially the Field-Reversed Configuration and the spheromak, attempt to combine the advantages of toroidal magnetic surfaces with those of a simply connected (non-toroidal) machine, resulting in a mechanically simpler and smaller confinement area. A Field-Reversed Configuration (FRC is a device developed for Magnetic fusion energy research that confines a plasma on closed magnetic field lines without a central A spheromak is a Magnetic fusion energy concept in which the plasma is in magnetohydrodynamic equilibrium In Topology, a geometrical object or space is called simply connected (or 1-connected) if it is Path-connected and every path between two points can be Compact toroids still have some enthusiastic supporters but are not backed as readily by the majority of the fusion community.
Finally, there are also electrostatic confinement fusion systems, in which ions in the reaction chamber are confined and held at the center of the device by electrostatic forces, as in the Farnsworth-Hirsch Fusor, which is not believed to be able to developed into a power plant. Inertial electrostatic confinement (often abbreviated as IEC) is a concept for retaining a plasma using an electrostatic field An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge The Farnsworth–Hirsch Fusor, or simply fusor, is an apparatus designed by Philo T The Polywell, an advanced variant of the fusor, has shown a degree of research interest as of late; however, the technology is relatively immature, and major scientific and engineering questions remain which researchers under the auspices of the U. The polywell is a plasma confinement concept that combines elements of Inertial electrostatic confinement and Magnetic confinement fusion, intended The Farnsworth–Hirsch Fusor, or simply fusor, is an apparatus designed by Philo T S. Office of Naval Research hope to further investigate. The Office of Naval Research ( ONR) headquartered in Arlington Virginia ( Ballston) is the office within the United States Department of the
A more subtle technique is to use more unusual particles to catalyse fusion. The best known of these is Muon-catalyzed fusion which uses muons, which behave somewhat like electrons and replace the electrons around the atoms. Muon-catalyzed fusion ( μCF) is a process allowing Nuclear fusion to take place at Temperatures significantly lower than the temperatures required for These muons allow atoms to get much closer and thus reduce the kinetic energy required to initiate fusion. Muons require more energy to produce than we can get back from muon-catalysed fusion, making this approach impractical for the generation of power.
Some researchers have reported excess heat, neutrons, tritium, helium and other nuclear effects in so-called cold fusion systems. Cold fusion, sometimes called low energy nuclear reactions (LENR or condensed matter nuclear science, is a set of effects reported in controversial laboratory experiments In 2004, a peer review panel was commissioned by the US Department of Energy to study these claims: two thirds of its members found the evidences of nuclear reactions unconvincing, five found the evidence "somewhat convincing" and one was entirely convinced. In 2006, Mosier-Boss and Szpak, researchers in the U.S. Navy's Space and Naval Warfare Systems Center San Diego, reported evidence of nuclear reactions, which have been independently replicated. Space and Naval Warfare Systems Center San Diego (SSC San Diego is the U 
Research into sonoluminescence induced fusion, sometimes known as "bubble fusion", also continues, although it is met with as much skepticism as cold fusion is by most of the scientific community. Sonoluminescence is the emission of short bursts of Light from imploding bubbles in a Liquid when excited by Sound. Bubble fusion, also known as sonofusion, is the non-technical name for a Nuclear fusion reaction hypothesized to occur during Sonoluminescence, an extreme
In fusion research, achieving a fusion energy gain factor Q = 1 is called breakeven and is considered a significant although somewhat artificial milestone. The fusion energy gain factor, usually expressed with the symbol Q, is the ratio of Fusion power produced in a Nuclear fusion reactor to the power required Ignition refers to an infinite Q, that is, a self-sustaining plasma where the losses are made up for by fusion power without any external input. In a practical fusion reactor, some external power will always be required for things like current drive, refueling, profile control, and burn control. A value on the order of Q = 20 will be required if the plant is to deliver much more energy than it uses internally.
There have been many design studies for fusion power plants. Despite many differences, there are several systems that are common to most. To begin with, a fusion power plant, like a fission power plant, is customarily divided into the nuclear island and the balance of plant. Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions The balance of plant is the conventional part that converts high-temperature heat into electricity via steam turbines. A steam turbine is a mechanical device that extracts Thermal energy from pressurized Steam, and converts it into useful mechanical work It is much the same in a fusion power plant as in a fission or coal power plant. In a fusion power plant, the nuclear island has a plasma chamber with an associated vacuum system, surrounded by plasma-facing components (first wall and divertor) maintaining the vacuum boundary and absorbing the thermal radiation coming from the plasma, surrounded in turn by a blanket where the neutrons are absorbed to breed tritium and heat a working fluid that transfers the power to the balance of plant. If magnetic confinement is used, a magnet system, using primarily cryogenic superconducting magnets, is needed, and usually systems for heating and refueling the plasma and for driving current. In inertial confinement, a driver (laser or accelerator) and a focusing system are needed, as well as a means for forming and positioning the pellets.
Although the standard solution for electricity production in fusion power plant designs is conventional steam turbines using the heat deposited by neutrons, there are also designs for direct conversion of the energy of the charged particles into electricity. These are of little value with a D-T fuel cycle, where 80% of the power is in the neutrons, but are indispensable with aneutronic fusion, where less than 1% is. Aneutronic fusion is any form of Fusion power where no more than 1% of the total energy released is carried by Neutrons Since the most-studied fusion reactions Direct conversion has been most commonly proposed for open-ended magnetic configurations like magnetic mirrors or Field-Reversed Configurations, where charged particles are lost along the magnetic field lines, which are then expanded to convert a large fraction of the random energy of the fusion products into directed motion. A magnetic mirror is a Magnetic field configuration where the field strength changes when moving along a field line A Field-Reversed Configuration (FRC is a device developed for Magnetic fusion energy research that confines a plasma on closed magnetic field lines without a central The particles are then collected on electrodes at various large electrical potentials. Typically the claimed conversion efficiency is in the range of 80%, but the converter may approach the reactor itself in size and expense.
Developing materials for fusion reactors has long been recognized as a problem nearly as difficult and important as that of plasma confinement, but it has received only a fraction of the attention. The International Fusion Material Irradiation Facility, also known as IFMIF, is an international scientific research program designed to test materials for suitability for use The neutron flux in a fusion reactor is expected to be about 100 times that in existing pressurized water reactors (PWR). Pressurized water reactor ( PWR s (also VVER if of Russian design are generation II nuclear power reactors that use ordinary Water Each atom in the blanket of a fusion reactor is expected to be hit by a neutron and displaced about a hundred times before the material is replaced. Furthermore the high-energy neutrons will produce hydrogen and helium in various nuclear reactions that tends to form bubbles at grain boundaries and result in swelling, blistering or embrittlement. One also wishes to choose materials whose primary components and impurities do not result in long-lived radioactive wastes. Finally, the mechanical forces and temperatures are large, and there may be frequent cycling of both.
The problem is exacerbated because realistic material tests must expose samples to neutron fluxes of a similar level for a similar length of time as those expected in a fusion power plant. Such a neutron source is nearly as complicated and expensive as a fusion reactor itself would be. Proper materials testing will not be possible in ITER, and a proposed materials testing facility, IFMIF, is still at the design stage in 2005. ITER is an international Tokamak ( Magnetic confinement fusion) research/engineering proposal for an experimental project that will help to make the transition from The International Fusion Material Irradiation Facility, also known as IFMIF, is an international scientific research program designed to test materials for suitability for use
The material of the plasma facing components (PFC) is a special problem. The PFC do not have to withstand large mechanical loads, so neutron damage is much less of an issue. They do have to withstand extremely large thermal loads, up to 10 MW/m², which is a difficult but solvable problem. Regardless of the material chosen, the heat flux can only be accommodated without melting if the distance from the front surface to the coolant is not more than a centimeter or two. The primary issue is the interaction with the plasma. One can choose either a low-Z material, typified by graphite although for some purposes beryllium might be chosen, or a high-Z material, usually tungsten with molybdenum as a second choice. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton The Mineral graphite, as with Diamond and Fullerene, is one of the Allotropes of carbon. Beryllium (bəˈrɪliəm is a Chemical element with the symbol Be and Atomic number 4 See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton Tungsten (ˈtʌŋstən also known as wolfram (/ˈwʊlfrəm/ is a Chemical element that has the symbol W and Atomic number 74 Molybdenum (məˈlɪbdənəm from the Greek word for the metal " Lead " is a Group 6 Chemical element with the symbol Mo Use of liquid metals (lithium, gallium, tin) has also been proposed, e. g. , by injection of 1-5 mm thick streams flowing at 10 m/s on solid substrates.
If graphite is used, the gross erosion rates due to physical and chemical sputtering would be many meters per year, so one must rely on redeposition of the sputtered material. Sputtering is a process whereby Atoms are Ejected from a solid target material due to bombardment of the target by energetic Ions It is commonly used for The location of the redeposition will not exactly coincide with the location of the sputtering, so one is still left with erosion rates that may be prohibitive. An even larger problem is the tritium co-deposited with the redeposited graphite. The tritium inventory in graphite layers and dust in a reactor could quickly build up to many kilograms, representing a waste of resources and a serious radiological hazard in case of an accident. The consensus of the fusion community seems to be that graphite, although a very attractive material for fusion experiments, cannot be the primary PFC material in a commercial reactor.
The sputtering rate of tungsten can be orders of magnitude smaller than that of carbon, and tritium is not so easily incorporated into redeposited tungsten, making this a more attractive choice. On the other hand, tungsten impurities in a plasma are much more damaging than carbon impurities, and self-sputtering of tungsten can be high, so it will be necessary to ensure that the plasma in contact with the tungsten is not too hot (a few tens of eV rather than hundreds of eV). Tungsten also has disadvantages in terms of eddy currents and melting in off-normal events, as well as some radiological issues.
It is far from clear whether nuclear fusion will be economically competitive with other forms of power. The many estimates that have been made of the cost of fusion power cover a wide range, and indirect costs of and subsidies for fusion power and its alternatives make any cost comparison difficult. The low estimates for fusion appear to be competitive with but not drastically lower than other alternatives. The high estimates are several times higher than alternatives.
While fusion power is still in early stages of development, vast sums have been and continue to be invested in research. In the EU almost € 10 billion was spent on fusion research up to the end of the 1990s, and the new ITER reactor alone is budgeted at € 10 billion. ITER is an international Tokamak ( Magnetic confinement fusion) research/engineering proposal for an experimental project that will help to make the transition from It is estimated that up to the point of possible implementation of electricity generation by nuclear fusion, R&D will need further promotion totalling around € 60-80 billion over a period of 50 years or so (of which € 20-30 billion within the EU).  Nuclear fusion research receives € 750 million (excluding ITER funding), compared with € 810 million for all non-nuclear energy research combined , putting research into fusion power well ahead of that of any single rivaling technology.
Fusion power would provide much more energy for a given weight of fuel than any technology currently in use, and the fuel itself (primarily deuterium) exists abundantly in the Earth's ocean: about 1 in 6500 hydrogen atoms in seawater is deuterium. Deuterium, also called heavy hydrogen, is a Stable isotope of Hydrogen with a Natural abundance in the Oceans of Earth  Although this may seem a low proportion (about 0. 015%), because nuclear fusion reactions are so much more energetic than chemical combustion and seawater is easier to access and more plentiful than fossil fuels, some experts estimate that fusion could supply the world's energy needs for centuries. 
An important aspect of fusion energy in contrast to many other energy sources is that the cost of production is inelastic. In Economics and business studies the price elasticity of demand (PED is a measure of the sensitivity of quantity demanded to changes in price The cost of wind energy, for example, goes up as the optimal locations are developed first, while further generators must be sited in less ideal conditions. With fusion energy, the production cost will not increase much, even if large numbers of plants are built. It has been suggested that even 100 times the current energy consumption of the world is possible.
Some problems which are expected to be an issue in the next century such as fresh water shortages can actually be regarded merely as problems of energy supply. Water resources are sources of Water that are useful or potentially useful to Humans Uses of water include Agricultural, industrial, Household For example, in desalination plants, seawater can be purified through distillation or reverse osmosis. Desalination, desalinization, or desalinisation refers to any of several processes that remove excess salt and other Minerals from Water Seawater is Water from a Sea or Ocean. On average seawater in the world's oceans has a Salinity of about 3 Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture Reverse osmosis (RO is a separation process that uses pressure to force a Solution through a membrane that retains the Solute on one side and allows the However, these processes are energy intensive. Even if the first fusion plants are not competitive with alternative sources, fusion could still become competitive if large scale desalination requires more power than the alternatives are able to provide.
Despite being technically non-renewable, fusion power has many of the benefits of long-term renewable energy sources (such as being a sustainable energy supply compared to presently-utilized sources and emitting no greenhouse gases) as well as some of the benefits of such much more limited energy sources as hydrocarbons and nuclear fission (without reprocessing). Non-renewable energy is energy taken from "finite resources that will eventually dwindle, becoming too expensive or too environmentally damaging to retrieve" Greenhouse gases are gaseous constituents of the atmosphere bothnatural and anthropogenic that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared Nuclear reprocessing separates components of Spent nuclear fuel such as Reprocessed uranium Plutonium Minor Like these currently dominant energy sources, fusion could provide very high power-generation density and uninterrupted power delivery (due to the fact that it is not dependent on the weather, unlike wind and solar power). The weather is a set of all the phenomena occurring in a given Atmosphere at a given Time.
Despite optimism dating back to the 1950s about the wide-scale harnessing of fusion power, there are still significant barriers standing between current scientific understanding and technological capabilities and the practical realization of fusion as an energy source. Research, while making steady progress, has also continually thrown up new difficulties. Therefore it remains unclear that an economically viable fusion plant is even possible.  An editorial in New Scientist magazine opined that "if commercial fusion is viable, it may well be a century away. New Scientist is a weekly International science magazine and website covering recent developments in science and technology for a general English -speaking " Ironically, a pamphlet printed by General Atomics in 1970's stated that "By the year 2000, several commercial fusion reactors are expected to be on-line. General Atomics is a nuclear physics and Defense contractor headquartered in San Diego California. "
Several fusion reactors have been built, but as yet none has produced more thermal energy than electrical energy consumed. Despite research having started in the 1950s, no commercial fusion reactor is expected before 2050. The ITER project is currently leading the effort to commercialize fusion power. ITER is an international Tokamak ( Magnetic confinement fusion) research/engineering proposal for an experimental project that will help to make the transition from
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