Fusion power

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Fusion power is a form of power plant in which energy is generated by using a fusion reaction to generate heat for a power plant. The fusion reaction brings together two lighter nuclei to form a heavier nucleus, releasing energy. Devices designed to utilize this energy are known as fusion reactors .

Fusion reactions usually occur in deuterium and tritium plasmas that are heated to millions of degrees Kelvin. In stars, gravity contains this fuel. Beyond the stars, the most studied way to limit plasma at this temperature is to use a magnetic field, although many other concepts have been tried. The main challenge in realizing fusion strength is to create a system that can limit the plasma long enough at high temperatures and densities.

As a source of energy, nuclear fusion has several theoretical advantages over fission. This includes reducing radioactivity in operations and less nuclear waste, sufficient fuel supply, and increased safety. However, controlled fusion has proved very difficult to produce in a practical and economical way. Research on fusion reactors began in the 1940s, but to date, no design has produced more fusion energy than the energy required to initiate a reaction, meaning that all existing designs have a negative energy balance.

Over the years, fusion researchers have been investigating various concepts of confinement. The initial emphasis on three main systems: z-pinch, stellarator and magnetic mirror. The current leading design is the tokamak and inertia confinement (ICF) by laser. Both designs are being built on a very large scale, especially ITER tokamak in France, and the National Ignition laser in the United States. The researchers also studied other designs that might offer a cheaper approach. Among these alternatives there is an increased interest in fusion of magnetic targets and inertia electrostatic confinement.

Video Fusion power

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Mechanism

Fusion reactions occur when two or more atomic nuclei are close enough for a long time so that the nuclear force pulls them together more than the electrostatic forces push them apart, combining them into heavier nuclei. For nuclei lighter than iron-56, the reaction is exothermic, releasing energy. For heavier nuclei of iron-56, the reaction is endothermic, requiring an external source of energy. Therefore, smaller nuclei of iron-56 are more likely to converge while heavier-than-56 iron is more likely to break.

Strong power acts only in short space. The disgusting electrostatic force acts on further distances. To undergo fusion, the atoms of the fuel should be given enough energy to approach one another close enough to a strong force to become active. The amount of kinetic energy required to carry fuel atoms close enough is known as the "Coulomb barrier". How to provide this energy include accelerating the atoms in particle accelerators, or heating them to high temperatures.

Once the atoms are heated above the ionization energy, the electron is stripped (it ionizes), leaving only the bare nucleus (ion). The result is a cloud of ionic heat and electrons that previously attached to them. This cloud is known as plasma. Because the charge is separated, the plasma is electrically conductive and is magnetically controlled. Many fusion devices make use of this to control particles when heated.

Cross Section

A cross-section of the reaction, denoted ?, is a measure of the probability that a fusion reaction will occur. It depends on the relative speed of the two cores. Higher relative velocities generally increase the probability, but the possibility of starting to decline again at a very high energy. The cross section for many fusion reactions is measured (especially in the 1970s) using particle beams.

In plasma, the particle velocity can be characterized using a probability distribution. If plasma is terminied, the distribution looks like a bell curve, or maxwellian distribution. In this case, it is useful to use the average particle cross section above the speed distribution. This is incorporated into the volumetric fusion rate:

$Â\; Â{\displaystyle Â\; Â\; Â\; Â\; Â\; Â\; Â}$ _{    Â   P                      fusion                          =                  n                        A                                   n               Â  <Â> B                          ?         ?            Â     v                        A         Â mo moan,    Â  <Â> B                          ?                  E                      fusion                                {\ displaystyle P _ {\ text {fusion}} = n_ {A} n_ {B} \ langle \ sigma v_ {A, B} \ rangle E _ {\ text {fusion}}}  Â}

dimana:

• ${\ displaystyle P _ {\ text {fusion}}}  ÂÂ$ adalah energi yang dibuat oleh fusi, per waktu dan volume
• n adalah kepadatan angka spesies A atau B, partikel dalam volume
• ${\ displaystyle \ langle \ sigma v_ {A, B} \ rangle}  ÂÂ$ adalah penampang melintang dari reaksi itu, rata-rata di atas semua kecepatan dari dua spesies v
• ${\ displaystyle E _ {\ text {fusion}}}  ÂÂ$ adalah energi yang dilepaskan oleh reaksi fusi tersebut.

Kriteria Lawson

Lawson's criteria show how energy output varies with temperature, density, speed of collision, and fuel. This equation is John Lawson's analysis center of fusion that works with hot plasma. Lawson assumes energy balance, shown below.

${\ displaystyle P _ {\ text {out}} = \ eta _ {\ text {capture}} \ left (P_ {\ text {fusion}} - P _ {\ text {conduction}} - P_ {\ text {radiation}} \ right)}$

• ? , efficiency
• ${\ displaystyle P _ {\ text {conduction}}}$ , conduction losses as massive energy
• ${\ displaystyle P _ {\ text {radiation}}}$
• ${\ displaystyle P _ {\ text {out}}}$ , clean power of fusion
• ${\ displaystyle P _ {\ text {fusion}}}$ , is the energy level generated by fusion reactions.

The plasma cloud loses energy through conduction and radiation. Conduction occurs when ions, electrons or neutrals affect other substances, usually the surface of the device, and transfer some of their kinetic energy to other atoms. Radiation is energy that leaves clouds as light in the visible UV, IR, or X-ray spectrum. Radiation increases with temperature. Fusion power technologies must overcome these losses.

Triple product: density, temperature, time

Criterion Lawson argues that the machine that holds the modified and quasi-neutral plasmas must meet the basic criteria to overcome the radiation losses, conduction losses and achieve 30 percent efficiency. This is known as "product three": plasma density, temperature and confinement time. Efforts to improve triple products lead to greater plant targeting. Larger plants move structural material farther from the center of the plasma, which reduces conduction losses and radiation because more radiation is reflected internally. This emphasis is on ${\ displaystyle (nT \ tau)}$ as success metrics have impacted other considerations such as cost, size, complexity, and efficiency. This has led to larger, more complicated, and more expensive machines like ITER and NIF.

Plasma Behavior

Plasma is an ionized gas that conducts electricity. In large quantities, it is modeled using magnetohydrodynamics, which is a combination of the Navier-Stokes equations governing fluids and the Maxwell equations governing how magnetic and electric fields behave. Fusion exploits several plasma properties, including:

Self-organizing plasma performs electric and magnetic fields. The movement can produce a field which in turn can contain it.

Plasagnetik diamagnetik can produce their own internal magnetic field. It can reject an externally applied magnetic field, making it magnetic.

The magnetic mirror can reflect the plasma as it moves from the low to high density plane.

Energy capture

Various approaches have been proposed to capture energy. The simplest is to heat the liquid. Most of the designs concentrate on D-T reactions, which release much energy in neutrons. Electricity is neutral, neutrons escape from confinement. In most such designs, it is eventually captured in the thick "lithium" sheets that surround the reactor core. When struck by high-energy neutrons, lithium can produce tritium, which is then fed back into the reactor. The energy of this reaction also heats the blanket, which is then actively cooled by the working fluid and then the liquid is used to drive the conventional turbine.

It has also been proposed to use neutrons to breed additional fission fuels in a nuclear waste blanket, a concept known as fusion-fusion hybrids. In this system, power output is enhanced by fission events, and power is extracted using systems such as those in conventional fission reactors.

The gas is heated to form a plasma that is hot enough to start a fusion reaction. A number of heating schemes have been explored:

Heating Radiofrequency The radio waves are applied to the plasma, causing it to oscillate. It's basically the same concept as a microwave oven. This is also known as resonance heating of cyclotron electrons or Dielectric heating.

Electrostatic Heating The electric field can work on charged ions or electrons, heating it up.

Neutral Beam Injection The external source of hydrogen is ionized and accelerated by an electric field to form a charged light that shines through a neutral source of hydrogen gas to a plasma which is itself ionized and contained in the reactor. by magnetic field. Some hydrogen gas intermediates are accelerated toward the plasma by collisions with charged light while remaining neutral: this neutral beam is unaffected by the magnetic field and shines through the plasma. Once inside the plasma, the neutral beam transmits energy to the plasma by a collision as a result of it being ionized and thus contained by the magnetic field so that both heating and refueling the reactor in one operation. The remainder of the charged beam is diverted by the magnetic field to the cooled beam dump.

Destruction of antiprotons Theoretically a number of antiprotons injected into the mass of fusion fuel can induce a thermonuclear reaction. This possibility as a method of propelling the spacecraft, known as an Antimatter catalyzed nuclear pulse drive, was investigated at Pennsylvania State University in connection with the proposed AIMStar project.

Magnetic Oscillation

Measurement

Thomson Scattering Light spreads from plasma. This light can be detected and used to reconstruct plasma behavior. This technique can be used to find the density and temperature. This is common in fusion of Inertial, Tokamax and fusor. In the ICF system, this can be done by firing a second ray into a gold foil adjacent to the target. This makes the X-ray diffuse or across the plasma. In Tokamaks, this can be done using mirrors and detectors to reflect light across a plane (two dimensional) or in one line (one dimension).

Langmuir Examination This is a metal object placed in the plasma. A potential is applied to it, giving it a positive or negative voltage to the surrounding plasma. Metals collect charged particles, draw current. When the voltage changes, the current changes. This makes Curve IV. Curve IV can be used to determine local plasma density, potential and temperature.

Neutron detectors Deuterium or tritium fusion produce neutrons. Neutrons interact with surrounding matter in a detectable manner. Several types of neutron detectors exist that can record the rate at which neutrons are produced during fusion reactions. They are an important tool for success.

Flux loop One wire loop is inserted into the magnetic field. As the field passes through the loop, a current is created. The current is measured and used to find the total magnetic flux through the loop. It has been used in National Compact Stellarator Experiment, polywell and LDX machines.

X-ray detector All plasma loses energy by emitting light. It covers the entire spectrum: visible, IR, UV, and X-ray. This happens whenever a particle changes its speed, for whatever reason. If the reason is a deflection by a magnetic field, the radiation is a cyclotron radiation at low speed and synchrotron radiation at high speed. If the reason is deflection by other particles, the plasma emits X-rays, known as Bremsstrahlung radiation. X-rays are termed hard and soft, based on their energy.

Power production

Steam turbine It has been proposed that a steam turbine is used to convert heat from the fusion chamber into electricity. The heat is transferred to the working fluid that turns into steam, pushing the electric generator.

Neutron blankets Deuterium and tritium fusion produce neutrons. It varies with the technique (NIF has 3E14 neutron records per second while the typical fusor produces 1E5-1E9 neutrons per second). It has been proposed to use these neutrons as a way to regenerate used fission fuels or as a means of breeding tritium using a bivalve blanket consisting of liquid lithium or, as in newer reactor designs, helium-cooled gravel beds consisting of lithium bearing gravel ceramics made from materials such as Lithium titanate, lithium orthosilicate or mixtures of these phases.

Direct Conversion This is a method in which the kinetic energy of a particle is converted into a voltage. It was first suggested by Richard F. Post in conjunction with a magnetic mirror, in the late sixties. It has also been suggested for Field-Reversed Configuration. The process of taking the plasma, expanding it, and converting most of the random energy from the fusion product into a directed movement. The particles are then collected on the electrodes in various large electrical potentials. This method has demonstrated experimental efficiency of 48 percent.

Maps Fusion power

Recordings

Fusion notes have been assigned by some devices. Here are some of them:

Q

The ratio of energy extracted to the amount of energy supplied. This record was considered to be regulated by Joint European Torus (JET) in 1997 when the device extracted 16 MW of power. However, this ratio can be seen in three different ways.

• 0.69 is the actual point in the time ratio between "fusion strength" and actual plasma input power (23 MW).
• 0.069 is the ratio between "fusion" power and power required to generate 23MW input power (basically taking into account the efficiency of the NB system).
• 0.0069 is the ratio between "fusion" power and total peak power required for JET pulses. This takes into account all the power of the grid plus one of the two large JET flywheel generators.

Runtime

In Field Reversed Configurations, the longest processing time is 300 ms, set by Princeton Field Reversed Configuration in August 2016. This does not involve fusion.

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Confinement

The cage refers to all the conditions necessary to keep the plasma solid and heat long enough to undergo fusion. Here are some general principles.

• Equilibrium: The force acting on the plasma should be balanced for containment. One exception is inertial confinement, where relevant physics must occur faster than disassembly time.
• Stability: Plasma must be constructed so that interference will not cause plasma discharge.
• Transportation or conduction: The loss of material must be slow enough. Plasma brings energy with it, so the rapid loss of material will disrupt the balance of engine power. Materials can be lost by transport to different regions or conduction through solid or liquid objects.

To produce independent fusion, the energy released by the reaction (or at least a small part) should be used to heat the new reactant nuclei and keep it for long enough so that they also experience fusion reactions.

Unconfigured

The first man-made large-scale fusion reaction was a test of the hydrogen bomb, Ivy Mike, in 1952. As part of the PACER project, it was proposed to use hydrogen bombs as a source of energy by blowing it up underground in the cave and then generating electricity from the heat generated, but such a power plant is impossible to build.

Magnetic confinement

At the temperature required for fusion, the fuel is heated to a plasma state. In these circumstances it has excellent electrical conductivity. This opens up the possibility of limiting plasma to magnetic fields, commonly known as magnetic confinement. The field lines place the Lorentz force on the plasma. The force works perpendicular to the magnetic field, so one problem in the magnetic cage prevents the plasma from leaking the ends of the field line. The general size of the magnetic trap in fusion is the beta ratio:

${\ displaystyle \ beta = {\ frac {p} {p_ {mag}}} = {\ frac {nk_ {B} T} {(B ^ {2}/2 \ mu_ {0})}}}  ÂÂ$

This is the ratio of the field applied externally to the plasma internal pressure. A value of 1 is an ideal trap. Some examples of beta values ​​include:

1. The machine is START: 0.32
2. An experimental dipole: 0.26
3. Spheromaks:? 0.1, Maximum 0.2 based on Mercier limits.
4. Machine DIII-D: 0.126
5. Dynamic Trap Magnetic mirror gas: 0.6 for 5E-3 seconds.
6. Continuous Spheromak Plasma Experiments at Los Alamos National labs & lt; 0.05 for 4E-6 seconds.

Magnetic Mirror One example of magnetic confinement is by the effect of magnetic mirror. If a particle follows a field line and enters an area with a higher field strength, the particles can be reflected. There are some devices that try to use this effect. The most famous is the magnetic mirror machine, which is a series of large and expensive devices built at Lawrence Livermore National Laboratory from the 1960s to the mid-1980s. Some other examples include a magnetic bottle and a Bicycle two point. Because the mirror machine is straight, they have advantages over the shape of the ring. First, the mirror is easier to create and maintain and the capture of a second direct conversion energy, easier to apply. Since the confinement achieved in the experiment is bad, this approach is abandoned.

Magnetic Loop Another example of magnetic confinement is to bend back the field lines on themselves, either in a circle or more commonly on a nested toroidal surface. The most developed system of this type is tokamak , with stellarator being the next most advanced, followed by the recording of the Reversed field. Compact toroids, especially Field-Reversed Configuration and spheromak, try to combine the superiority of the toroidal magnetic surface with a connected (non-toroidal) engine, resulting in a simpler and smaller mechanical confinement. area.

Inertial confinement

Inertial confinement is the use of rapidly exploding shells to heat and limit the plasma. This shell is implanted using direct laser blast (direct drive) or secondary X-ray (indirect drive) or heavy ion beam blast. Theoretically, fusion using a laser will be done using a small fuel pellet that explodes several times in one second. To induce an explosion, the pellet must be compressed up to about 30 times the density of the solid with energetic beams. If the direct propulsion is used - the beam is focused directly on the pellets - in principle it can be very efficient, but in practice it is difficult to get the required uniformity. Alternative approach, indirect drive, using beam to heat the shell, and then shells emit x-rays, which then coat the pellets. Beams are generally laser beams, but heavy and light ion beams and electron beams have been investigated.

Electrostatic confinement

There is also an electrostatic locking fusion device. This device limits the ions using electrostatic fields. The best known is Fusor. This device has a cathode inside an anode wire enclosure. The positive ion flies in the negative inner direction, and is heated by an electric field in the process. If they lose their inner cages they can collide and unite. Ions usually hit the cathode, however, creating a high conduction loss. Also, the fusion rate in the fusor is very low due to competitive physical effects, such as the loss of energy in the form of light radiation. The design has been proposed to avoid cage-related problems, by producing fields using non-neutral clouds. These include plasma oscillating devices, a grid-shielded magnet, writing traps, polywell and the concept of F1 cathode drivers. The technology is relatively immature, however, and many scientific and engineering questions remain.

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History of research

1920s

The study of nuclear fusion began in the early 20th century. In 1920 the British physicist Francis William Aston discovered that the total mass equivalent to four hydrogen atoms (two protons and two neutrons) was heavier than the total mass of one helium atom (He-4), implying that clean energy could be released by combining the hydrogen atoms together equals to form helium, and gives the first clue of the mechanism by which the star can produce energy in quantities measured. Throughout the 1920s, Arthur Stanley Eddington became a major proponent of the proton-proton chain reaction (PP reaction) as the main system running the Sun.

1930s

Neutron from fusion was first detected by Ernest Rutherfords' staff member at the University of Cambridge, in 1933. This experiment was developed by Mark Oliphant and involved the acceleration of protons toward targets at energies up to 600,000 electron volts. In 1933, the Cavendish Laboratory received a gift from American physical chemist Gilbert N. Lewis from a few drops of heavy water. Accelerators are used to fire heavy hydrogen nuclei deuterons at various targets. Working with Rutherford and others, Oliphant discovered the core of Helium-3 ( helion ) and tritium ( tritons ).

A theory verified by Hans Bethe in 1939 which suggests that beta decay and a quantum tunnel in the core of the Sun can convert one proton into a neutron and thus produce deuterium rather than a diproton. Deuterium will then melt through another reaction to further increase the energy output. For this work, Bethe won the Nobel Prize in Physics.

1940s

In 1942, nuclear fusion research was incorporated into the Manhattan Project when the secrecy surrounding the field was obscured by science. The first patent related to the fusion reactor was registered in 1946 by the Royal Atomic Energy Authority of the United Kingdom. The discoverers are Sir George Paget Thomson and Moses Blackman. This is the first detailed examination of the Z-pinch concept.

Z-pinch is based on the fact that plasmas do electrically. Running the current through the plasma, will produce a magnetic field around the plasma. This field will, according to Lenz's law, create an inward-directed force that causes plasma to collapse inward, increasing its density. The dense plasm produces a denser magnetic field, increasing inward strength, leading to chain reactions. If the condition is right, this may cause the density and temperature required for fusion. The difficulty is to insert the current into the plasma, which will usually melt the mechanical electrode. A solution comes up again because of its good plasma properties; by placing the plasma in the center of the electromagnet, the induction can be used to generate the current.

Beginning in 1947, two British teams conducted a small experiment and began building a series of ever-larger experiments. When Huemul's results hit the news (see below), James L. Tuck, a British physicist working at Los Alamos, introduced the concept of pinch in the US and produced a series of machines known as Maybeatron. The Soviet Union, unbeknownst to the West, also built a series of similar machines. All of these devices quickly show a series of instabilities when pinch is applied. It breaks down the plasma columns long before it reaches the density and temperature required for fusion.

1950s

The first successful man-made fusion device was a boosted fission weapon that was tested in 1951 in the Greenhouse Item test. This was followed by a true fusion weapon in 1952, Ivy Mike, and the first practical examples of 1954's Castle Bravo. This is an uncontrolled fusion. In this device, the energy released by the fission explosion is used to compress and heat the fusion fuel, initiating the fusion reaction. Fusion releases neutrons. These neutrons hit the surrounding fission fuel, causing the atoms to split faster than the normal fission process - almost instantaneously by comparison. This increases the effectiveness of bombs: normal fission weapons spurt themselves before all of their fuel is used; fusion/fission weapons do not have this practical upper limit.

In 1949, an expatriate German, Ronald Richter, proposed the Huemul Project in Argentina, announced a positive result in 1951. This turned out to be false, but encouraged a great interest in this concept as a whole. In particular, it encouraged Lyman Spitzer to begin considering ways to solve some of the more obvious problems involved in limiting hot plasma, and, unaware of the z-pinch effort, he developed a new solution to a problem known as a stellarator. Spitzer applied to the US Atomic Energy Commission for funding to build test kits. During this period, Jim Tuck who has worked with the British team has introduced the z-pinch concept to his co-workers in his new job at Los Alamos National Laboratory (LANL). When he heard about Spitzer's chances of funding, he applied to build his own machine, Probatron.

Spitzer's idea won the funding and he started working on a stellarator with the code name Project Matterhorn. His work led to the creation of the Princeton Plasticma Physics Laboratory. Tuck back to the LANL and set up local funding to build the engine. At this time, however, it is clear that all pinch machines suffer from the same problems that involve stability, and progress stops. In 1953, Tuck and the others proposed a number of solutions to the problem of stability. This led to the design of the second shaving machine series, led by ZETA UK and Scepter devices.

Spitzer has planned an aggressive development project of four engines, A, B, C, and D. A and B are small research devices, C will be prototypes of power generators, and D will be the prototype of a commercial device. A works without problems, but even when B is used, it is clear that the stellarator also suffers from plasma instability and leakage. Progress on C is slowed as an attempt is made to remedy this problem.

By the mid-1950s it was clear that the simple theoretical tools used to calculate the performance of all fusion machines did not predict their actual behavior. Machines always extract their plasma from the confinement area at a price much higher than expected. In 1954, Edward Teller convened a meeting of fusion researchers at Princeton Gun Club, close to Project Matterhorn (now known as Sherwood Project). Teller begins by pointing out the problems that everyone is facing, and suggests that any system in which the plasma is confined to a concave field must fail. Participants remembered him saying something that indicated that the fields were like rubber bands, and they would try to return to a straight configuration each time the power was raised, removing the plasma. He goes on to say that it appears the only way to limit the plasma in a stable configuration would be to use a convex plane, a "cusp" configuration.

When the meeting ended, most researchers quickly found a paper that said why Teller's concerns do not apply to their specific device. The pinch machine does not use the magnetic field in this way at all, while the mirror and the stellarator seem to have various ways. This was soon followed by a paper by Martin David Kruskal and Martin Schwarzschild discussing the pinch machine, however, which indicates instability in the device attached to the design.

The largest "classic" pinch device is ZETA, including all of these suggested improvements, starting operations in Britain in 1957. In early 1958, John Cockcroft announced that fusion was achieved at ZETA, the announcement that made headlines around the world.. When physicists in the US expressed concern about their claims initially dismissed. US experiments soon showed the same neutrons, although temperature measurements suggest this can not be from fusion reactions. The neutrons seen in England were then demonstrated to come from different versions of the same instability process that hit the previous machine. Cockcroft was forced to withdraw fusion claims, and the whole field was tarnished for years. ZETA ended its experiment in 1968.

The first experiment to achieve controlled thermonuclear fusion was achieved by using Scylla I at Los Alamos National Laboratory in 1958. Scylla I was a machine? -pinch, with a full cylinder of deuterium. Electric current through the cylinder side. The magnetic field created now pinches the plasma, raising the temperature to 15 million degrees Celsius, long enough for the atoms to converge and produce neutrons.

In 1950-1951 I.E. Tamm and A.D. Sakharov in the Soviet Union, first discussed approaches such as tokamak. Experimental research on the design began in 1956 at the Kurchatov Institute in Moscow by a group of Soviet scientists led by Lev Artsimovich. Tokamak basically combines low-power pinch devices with simple low-power stellarators. The key is to combine the plane in such a way that the particles orbiting inside the reactor several times, today are known as "safety factors". The combination of these fields dramatically increases the time and density of the confinement, resulting in major improvements to existing devices.

1960s

A key plasma physics text was published by Lyman Spitzer at Princeton in 1963. Spitzer took the ideal gas law and adapted it to the ionized plasma, developing many of the fundamental equations used to model plasma.

Laser fusion was suggested in 1962 by scientists at Lawrence Livermore National Laboratory, shortly after the invention of the laser itself in 1960. At that time, the laser was a low power engine, but low-level research began in 1965. Laser fusion, formally known as a fusion of inertial confinement, involves exploding the target by using a laser beam. There are two ways to do this: indirect drives and direct drives. In direct driving, the laser detonates the fuel pellet. In an indirect drive, the laser detonates the structure around the fuel. This makes X-rays suppress the fuel. Both methods condense the fuel so that fusion can occur.

At the 1964 World Expo, the public was given the first demonstration of nuclear fusion. The device is? -pinch from General Electric. This is similar to the Scylla engine developed earlier in Los Alamos.

The magnetic mirror was first published in 1967 by Richard F. Post and many others at Lawrence Livermore National Laboratory. The mirror consists of two large magnets arranged so that they have a strong field in them, and a weaker, but connected, field between them. Plasma introduced in the area between two magnets will "bounce back" from a stronger field in the middle.

Group A.D. Sakharov built the first tokamaks, the most successful being the T-3 and the larger version of the T-4. T-4 was tested in 1968 in Novosibirsk, producing the world's first quasistationary fusion reaction. When it was first announced, the international community was highly skeptical. However, a British team was invited to see the T-3, and after measuring it in depth, they released results that confirmed the Soviet claim. An explosion of activity is followed because many devices are planned to be abandoned and new tokamaks are introduced in their place - the C model stellarator, which is being built after much redesign, is quickly converted into a Symmetrical Tokamak.

In his work with a vacuum tube, Philo Farnsworth observed that the electrical charge would accumulate in the tube region. Today, this effect is known as the Multipactor effect. Farnsworth reasoned that if the ions were concentrated high enough, they could collide and unite. In 1962, he filed a patent on the design using a positive inner cage to center the plasma, to achieve nuclear fusion. During this time, Robert L. Hirsch joined the Farnsworth Television labs and began working on what became a fusor. Hirsch patented the design in 1966 and published its design in 1967.

1970s

In 1972, John Nuckolls outlined the idea of ​​ignition. This is a fusion chain reaction. Hot helium made during fusion reheats the fuel and starts more reactions. John argued that the ignition would require a laser about 1 kJ. This turned out to be wrong. The Nuckolls paper started a major development effort. Some laser systems are built in LLNL. These included argus, Cyclops, Janus, long lines, Siwa lasers and Nova in 1984. This prompted the UK to build the Laser Facility Center in 1976.

During this time, major steps in understanding the tokamak system were made. A number of design improvements are now part of the concept of "advanced tokamak", which includes non-circle plasma, internal switching and barrier, often superconducting magnets, and operating on an island called "H-mode" stability enhancement. Two other designs have also been well studied; a compact tokamak is connected to a magnet inside the vacuum, while a round tokamak reduces the cross section as much as possible.

In 1974 a study of ZETA results showed interesting side effects; after the experiment runs over, the plasma will enter a short period of stability. This leads to the concept of inverted pinch fields, which have seen several levels of development since. On May 1, 1974, the KMS fusion company (founded by Kip Siegel) achieved the world's first laser induced fusion in deuterium-tritium pellets.

In the mid-1970s, the PACER Project, conducted at Los Alamos National Laboratory (LANL) explored the possibility of a fusion power system that would involve small hydrogen bomb explosions (fusion bombs) inside the underground cavities. As an energy source, this system is the only fusion strength system that can be shown to work using existing technology. It will also require a large and continuous supply of nuclear bombs, making the economy of such a system somewhat questionable.

In 1976, two Argus beam lasers became operational in the livermore. In 1977, The Shiva 20 beam laser in Livermore was completed, capable of delivering 10.2 kilojoules of infrared energy as per the target. At a price of $ 25 million and a size close to the field of football, Shiva is the first of the megalasers. In the same year, the JET project was approved by the European Commission and a site was selected.

1980s

As a result of advocacy, cold war, and the energy crisis of the 1970s, major magnetic mirror programs were funded by the US federal government in the late 1970s and early 1980s. The program produces a series of large magnetic mirror devices including: 2X, Baseball I, Baseball II, Tandem Mirror Experiment, Tandem mirror trial upgrade, Fusion Mirror Test Facility and MFTF-B. These machines were built and tested in Livermore from the late 1960s to the mid-1980s. A number of institutions collaborate on these machines, conducting experiments. These include the Institute for Advanced Study and the University of Wisconsin-Madison. The final machine, the Fusion Mirror Test Facility cost $ 372 million and, at that time, was the most expensive project in Livermore's history. Opened on 21 February 1986 and immediately closed. The reason given is to balance the federal budget of the United States. The program is supported from within Carter and the early Reagan administration by Edwin E. Kintner, a US Navy captain, under Alvin Trivelpiece.

In Laser fusion lasts: in 1983, the NOVETTE laser was completed. December 1984 following, NAVA laser ten ray finish. Five years later, NOVA will produce a maximum of 120 kilojoules of infrared light, over a nanosecond pulse. Meanwhile, efforts are focused on fast delivery or subtlety of the file. Both try to channel energy uniformly to blow up the target. One of the initial problems is that the light is in the infrared wavelength, losing a lot of energy before hitting the fuel. The breakthrough was done at the Laboratory for Laser Energetics at the University of Rochester. The Rochester scientists used a threefold frequency crystal to convert infrared laser light into ultraviolet light. In 1985, Donna Strickland and GÃÆ' Â © rard Mourou invented a method for amplifying laser pulses with "twitter". This method converts one wavelength into a full spectrum. The system then amplifies the laser at each wavelength and then rearranges the beam into a single color. The amplification of throbbing chirp became instrumental in establishing the National Ignition Facility and the Omega EP system. Most of the research on ICF is aimed at weapons research, because the explosion is relevant to nuclear weapons.

During this time Los Alamos National Laboratory built a series of laser facilities. These include Gemini (two-beam system), Helios (eight blocks), Antares (24 beam) and Aurora (96 beam). The program ended in the early nineties at a cost of about a billion dollars.

In 1987, Akira Hasegawa noticed that in a dipolar magnetic field, fluctuations tend to compress the plasma without losing energy. This effect is seen in data taken by Voyager 2, when Uranus encounters it. This observation will be the basis for a fusion approach known as a Levitated dipole.

At Tokamaks, Tore Supra was being built in the mid-eighties (1983 to 1988). This is a Tokamak built in Cadarache, France. In 1983, JET was completed and the first plasma was reached. In 1985, Japanese tokamak, JT-60 finished. In 1988, a T-15 a Soviet tokamak was completed. This is the first industrial fusion reactor that uses superconducting magnets to control plasma. It is a cooled Helium.

In 1989, Pons and Fleischmann submitted a paper to the Journal of Chemical Electroanalysis claiming that they had observed fusion in a room temperature device and revealed their work in a press release. Some scientists report the excess heat, neutrons, tritium, helium and other nuclear effects in so-called cold fusion systems, which temporarily earn interest as showing promise. Expectations fall when replication failure is weighed for several reasons cold fusion is unlikely, the discovery of a possible source of experimental error, and finally the discovery that Fleischmann and Pons did not actually detect a byproduct of nuclear reaction. By the end of 1989, most scientists considered cold fusion to claim death, and cold fusion later gained a reputation as pathological science. However, small community researchers continue to investigate cold fusion that claims to replicate Fleishmann and Pons results including by-products of nuclear reactions. Claims associated with cold fusion are largely unreliable in the mainstream scientific community. In 1989, the majority of review panels hosted by the US Department of Energy (DOE) found that evidence for the discovery of a new nuclear process was not persuasive. The second DOE review, held in 2004 to see new research, reached a similar conclusion with the first.

In 1984, Martin Peng of ORNL proposed an alternate arrangement of magnetic coils that would greatly reduce aspect ratio while avoiding the problem of compact tokamak erosion: a round-shaped tokamak. Instead of installing each magnetic coil separately, it proposes using one large conductor in the middle, and attaching a magnet as a half ring of this conductor. What was once a series of individual rings passing through the hole at the center of the reactor was reduced to a single post, allowing an aspect ratio as low as 1.2. The ST concept appears to represent a remarkable improvement in tokamak design. However, it is being proposed during a period when the US fusion research budget is declining dramatically. ORNL was awarded funds to develop an appropriate middle column built from a high-strength copper alloy called "Glidcop". However, they can not secure funding to build a demonstration machine, "STX". Failed to build ST in ORNL, Peng started a worldwide effort to attract another team in ST concept and get a test machine built. One way to do this quickly is to convert the spheromak machine to the Spherical tokamak layout. Peng Advocacy also captures the interest of Derek Robinson, from the fusion center of the British Atomic Energy Authority at Culham. Robinson was able to put the team together and secure funding in the order of 100,000 pounds to build an experimental engine, a Tight Tokamak Small Aspect Ratio, or START. Parts of the machine were recycled from previous projects, while others were lent from other laboratories, including a neutral 40 neutral light from ORNL. START Construction started in 1990, assembled quickly and commenced operations in January 1991.

1990s

In 1991, the Introductory Tritium Experiments at European Together Torus in England achieved the release of the world's first controlled fusion power.

In 1992, a major article was published in Physics Today by Robert McCory at the Laboratory for laser energy that outperformed the current ICF situation and advocated a national ignition facility. This was followed up by a major review article, from John Lindl in 1995, advocating for NIF. During this time a number of ICF subsystems are expanding, including target manufacturing, cryogenic handling systems, new laser designs (especially NIKE lasers in NRL) and diagnostic improvements such as flight analysis time and Thomson scattering. This work is done on the NOVA laser system, General Atomics, Laser MÃÆ'Ã… © gajoule and GEKKO XII systems in Japan. Through this work and lobbying by groups such as the fusion power association and John Sethian in the NRL, the vote was held at the congress, granting the funding authority for the NIF project in the late nineties.

In the early nineties, experimental theories and work on fusors and poliwell were published. In response, Todd Rider at MIT developed a common model of this device. Rider argues that all plasma systems on thermodynamic equilibrium are fundamentally limited. In 1995, William Nevins published a criticism stating that the particles within the fuser and the polywell would build angular momentum, causing dense cores to be degraded.

In 1995, the University of Wisconsin-Madison built a large fusor, known as HOMER, which is still operating. Meanwhile, Dr. George H. Miley in Illinois, builds a small fusor that generates neutrons using deuterium gas and finds "star mode" of the fusor operation. The following year, the first "IEC Fusion Japan-Japan" Workshop was conducted, and in Europe, IEC devices were developed as a source of commercial neutrons by Daimler-Chrysler and NSD Fusion.

In 1996, the Z-engine was upgraded and opened to the public by the US Army in August 1998 in Scientific American. The Sandia Z machine key attribute is 18 million amperes and discharge time is less than 100 nanoseconds. This produces a magnetic pulse, inside a large oil tank, it attacks a tungsten wire array called liner . Z-Sacking machine has become a way to test very high energy conditions, high temperatures (2 billion degrees). In 1996, Tore Supra created a plasma for two minutes with a current of nearly 1 million amperes driven non-inductively by a 2.3 MW lower frequency hybrid wave. This is 280 MJ of energy that is injected and extracted. This result is possible because the active active plasma component is activated

In 1997, JET produced a peak of 16.1MW of fusion power (65% of heat to plasma), with a fusion strength of over 10MW sustained for more than 0.5 seconds. His successor, the International Thermonuclear Experimental Reactor (ITER), was officially announced as part of a seven-party consortium (six countries and the European Union). ITER is designed to generate 10 times more fusion power than power put into plasma. ITER is currently being built in Cadarache, France.

In the late nineties, a team at Columbia University and MIT developed a dipole which was a fusion device consisting of a superconducting electromagnet, floating in a dish-shaped vacuum chamber. Plasma swirls around this donut and fused along the central axis.

2000s

In the peer-reviewed journal of March 8, 2002, Rusi P. Taleyarkhan and colleagues at Oak Ridge National Laboratory (ORNL) reported that acoustic cavitation experiments were performed with de-sterilized acetone (C ₃ D ₆ O) shows the tritium and neutron output measurements consistent with the occurrence of fusion. Taleyarkhan was later found guilty of mistakes, the Naval Research Office deters him for 28 months from receiving the Federal Fund, and his name is listed in the 'Excluded Party List'.

"Fast ignition" was developed in the late nineties, and is part of a boost by the Laboratory for Laser Energetics to build the Omega EP system. The system was completed in 2008. Quick ignition shows dramatic power savings so that ICF seems to be a useful technique for energy production. There is even a proposal to build an experimental facility dedicated to the rapid ignition approach, known as HiPER.

In April 2005, a team from UCLA announced it had devised a way of producing fusion using a "laboratory-compatible" machine, using lithium tantalate to generate enough tension to destroy deuterium atoms together. The process, however, does not produce clean power (see Pyroelectric fusion). Such a tool would be useful in the same role as the fusor. In 2006, China's EAST test reactor was completed. This is the first tokamak that uses superconductive magnets to produce toroidal and poloidal fields.

In the early 2000s, researchers at LANL argued that oscillating plasmas could be at local thermodynamic equilibrium. This encourages the design of POPS and Penning trap. At this time, researchers at MIT became interested in fusors for space propulsion and powering space vehicles. Specifically, the researchers developed a fusor with several inner cages. Greg Piefer graduated from Madison and founded Phoenix Nuclear Labs, a company that developed the fusor into a source of neutrons for the mass production of medical isotopes. Robert Bussard started talking openly about Polywell in 2006. He tried to generate interest

Source of the article : Wikipedia