List of fusion experiments
Experiments directed toward developing fusion power are invariably done with dedicated machines which can be classified according to the principles they use to confine the plasma fuel and keep it hot.
The major division is between magnetic confinement and inertial confinement. In magnetic confinement, the tendency of the hot plasma to expand is counteracted by the Lorentz force between currents in the plasma and magnetic fields produced by external coils. The particle densities tend to be in the range of to and the linear dimensions in the range of. The particle and energy confinement times may range from under a millisecond to over a second, but the configuration itself is often maintained through input of particles, energy, and current for times that are hundreds or thousands of times longer. Some concepts are capable of maintaining a plasma indefinitely.
In contrast, with inertial confinement, there is nothing to counteract the expansion of the plasma. The confinement time is simply the time it takes the plasma pressure to overcome the inertia of the particles, hence the name. The densities tend to be in the range of to and the plasma radius in the range of 1 to 100 micrometers. These conditions are obtained by irradiating a millimeter-sized solid pellet with a nanosecond laser or ion pulse. The outer layer of the pellet is ablated, providing a reaction force that compresses the central 10% of the fuel by a factor of 10 or 20 to 103 or times solid density. These microplasmas disperse in a time measured in nanoseconds. For a fusion power reactor, a repetition rate of several per second will be needed.
Magnetic confinement
Within the field of magnetic confinement experiments, there is a basic division between toroidal and open magnetic field topologies. Generally speaking, it is easier to contain a plasma in the direction perpendicular to the field than parallel to it. Parallel confinement can be solved either by bending the field lines back on themselves into circles or, more commonly, toroidal surfaces, or by constricting the bundle of field lines at both ends, which causes some of the particles to be reflected by the mirror effect. The toroidal geometries can be further subdivided according to whether the machine itself has a toroidal geometry, i.e., a solid core through the center of the plasma. The alternative is to dispense with a solid core and rely on currents in the plasma to produce the toroidal field.Mirror machines have advantages in a simpler geometry and a better potential for direct conversion of particle energy to electricity. They generally require higher magnetic fields than toroidal machines, but the biggest problem has turned out to be confinement. For good confinement there must be more particles moving perpendicular to the field than there are moving parallel to the field. Such a non-Maxwellian velocity distribution is, however, very difficult to maintain and energetically costly.
The mirrors' advantage of simple machine geometry is maintained in machines which produce compact toroids, but there are potential disadvantages for stability in not having a central conductor and there is generally less possibility to control the magnetic geometry. Compact toroid concepts are generally less well developed than those of toroidal machines. While this does not necessarily mean that they cannot work better than mainstream concepts, the uncertainty involved is much greater.
Somewhat in a class by itself is the Z-pinch, which has circular field lines. This was one of the first concepts tried, but it did not prove very successful. Furthermore, there was never a convincing concept for turning the pulsed machine requiring electrodes into a practical reactor.
The dense plasma focus is a controversial and "non-mainstream" device that relies on currents in the plasma to produce a toroid. It is a pulsed device that depends on a plasma that is not in equilibrium and has the potential for direct conversion of particle energy to electricity. Experiments are ongoing to test relatively new theories to determine if the device has a future.
Toroidal machine
Toroidal machines can be axially symmetric, like the tokamak and the reversed field pinch, or asymmetric, like the stellarator. The additional degree of freedom gained by giving up toroidal symmetry might ultimately be usable to produce better confinement, but the cost is complexity in the engineering, the theory, and the experimental diagnostics. Stellarators typically have a periodicity, e.g. a fivefold rotational symmetry. The RFP, despite some theoretical advantages such as a low magnetic field at the coils, has not proven very successful.Tokamak
Stellarator
| Device Name | Status | Construction | Operation | Type | Location | Organisation | Major/Minor Radius | B-field | Purpose | Image |
| Model A | 1952-1953 | 1953-? | Figure-8 | Princeton  | Princeton Plasma Physics Laboratory | 0.3 m/0.02 m | 0.1 T | First stellarator | ||
| Model B | 1953-1954 | 1954-1959 | Figure-8 | Princeton | Princeton Plasma Physics Laboratory | 0.3 m/0.02 m | 5 T | Development of plasma diagnostics | ||
| Model B-1 | ?-1959 | Figure-8 | Princeton | Princeton Plasma Physics Laboratory | 0.25 m/0.02 m | 5 T | Yielded 1 MK plasma temperatures | |||
| Model B-2 | 1957 | Figure-8 | Princeton | Princeton Plasma Physics Laboratory | 0.3 m/0.02 m | 5 T | Electron temperatures up to 10 MK | |||
| Model B-3 | 1957 | 1958- | Figure-8 | Princeton | Princeton Plasma Physics Laboratory | 0.4 m/0.02 m | 4 T | Last figure-8 device, confinement studies of ohmically heated plasma | ||
| Model B-64 | 1955 | 1955 | Square | Princeton | Princeton Plasma Physics Laboratory | ? m/0.05 m | 1.8 T | |||
| Model B-65 | 1957 | 1957 | Racetrack | Princeton | Princeton Plasma Physics Laboratory | |||||
| Model B-66 | 1958 | 1958-? | Racetrack | Princeton | Princeton Plasma Physics Laboratory | |||||
| Wendelstein 1-A | 1960 | Racetrack | Garching  | Max-Planck-Institut für Plasmaphysik | 0.35 m/0.02 m | 2 T | ℓ=3 | |||
| Wendelstein 1-B | 1960 | Racetrack | Garching | Max-Planck-Institut für Plasmaphysik | 0.35 m/0.02 m | 2 T | ℓ=2 | |||
| Model C | →ST | 1957-1962 | 1962-1969 | Racetrack | Princeton | Princeton Plasma Physics Laboratory | 1.9 m/0.07 m | 3.5 T | Found large plasma losses by Bohm diffusion | |
| L-1 | 1963 | 1963-1971 | Lebedev  | Lebedev Physical Institute | 0.6 m/0.05 m | 1 T | ||||
| SIRIUS | 1964-? | Kharkov | ||||||||
| TOR-1 | 1967 | 1967-1973 | Lebedev | Lebedev Physical Institute | 0.6 m/0.05 m | 1 T | ||||
| TOR-2 | ? | 1967-1973 | Lebedev | Lebedev Physical Institute | 0.63 m/0.036 m | 2.5 T | ||||
| Wendelstein 2-A | 1965-1968 | 1968-1974 | Heliotron | Garching | Max-Planck-Institut für Plasmaphysik | 0.5 m/0.05 m | 0.6 T | Good plasma confinement “Munich mystery” | ||
| Wendelstein 2-B | ?-1970 | 1971-? | Heliotron | Garching | Max-Planck-Institut für Plasmaphysik | 0.5 m/0.055 m | 1.25 T | Demonstrated similar performance than tokamaks | ||
| L-2 | ? | 1975-? | Lebedev | Lebedev Physical Institute | 1 m/0.11 m | 2.0 T | ||||
| WEGA | →HIDRA | 1972-1975 | 1975-2013 | Classical stellarator | Greifswald | Max-Planck-Institut für Plasmaphysik | 0.72 m/0.15 m | 1.4 T | Test lower hybrid heating | |
| Wendelstein 7-A | ? | 1975-1985 | Classical stellarator | Garching | Max-Planck-Institut für Plasmaphysik | 2 m/0.1 m | 3.5 T | First "pure" stellarator without plasma current | ||
| Heliotron-E | ? | 1980-? | Heliotron |  | 2.2 m/0.2 m | 1.9 T | ||||
| Heliotron-DR | ? | 1981-? | Heliotron | | 0.9 m/0.07 m | 0.6 T | ||||
| Uragan-3 | ? | 1982-? | Torsatron | Kharkiv  | National Science Center, Kharkiv Institute of Physics and Technology | 1.0 m/0.12 m | 1.3 T | ? | ||
| Auburn Torsatron | ? | 1984-1990 | Torsatron | Auburn | Auburn University | 0.58 m/0.14 m | 0.2 T | |||
| :de:Wendelstein 7-AS|Wendelstein 7-AS | 1982-1988 | 1988-2002 | Modular, advanced stellarator | Garching | Max-Planck-Institut für Plasmaphysik | 2 m/0.13 m | 2.6 T | First H-mode in a stellarator in 1992 | ||
| Advanced Toroidal Facility | 1984-1988 | 1988-? | Torsatron | Oak Ridge | Oak Ridge National Laboratory | 2.1 m/0.27 m | 2.0 T | High-beta operation | ||
| Compact Helical System | ? | 1989-? | Heliotron | Toki | National Institute for Fusion Science | 1 m/0.2 m | 1.5 T | |||
| Compact Auburn Torsatron | ?-1990 | 1990-2000 | Torsatron | Auburn | Auburn University | 0.53 m/0.11 m | 0.1 T | Study magnetic flux surfaces | ||
| H-1NF | 1992- | Heliac | Canberra  | Research School of Physical Sciences and Engineering, Australian National University | 1.0 m/0.19 m | 0.5 T | ||||
| TJ-K | TJ-IU | 1994- | Torsatron | Kiel, Stuttgart | University of Stuttgart | 0.60 m/0.10 m | 0.5 T | Teaching | ||
| TJ-II | 1991- | 1997- | flexible Heliac | Madrid  | National Fusion Laboratory, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas | 1.5 m/0.28 m | 1.2 T | Study plasma in flexible configuration | ||
| LHD | 1990-1998 | 1998- | Heliotron | Toki | National Institute for Fusion Science | 3.5 m/0.6 m | 3 T | Determine feasibility of a stellarator fusion reactor | ||
| HSX | 1999- | Modular, quasi-helically symmetric | Madison | University of Wisconsin–Madison | 1.2 m/0.15 m | 1 T | investigate plasma transport | |||
| Heliotron J | 2000- | Heliotron | Kyoto | Institute of Advanced Energy | 1.2 m/0.1 m | 1.5 T | Study helical-axis heliotron configuration | |||
| Columbia Non-neutral Torus | ? | 2004- | Circular interlocked coils | New York City | Columbia University | 0.3 m/0.1 m | 0.2 T | Study of non-neutral plasmas | ||
| Uragan-2 | 1988-2006 | 2006- | Heliotron, Torsatron | Kharkiv | National Science Center, Kharkiv Institute of Physics and Technology | 1.7 m/0.24 m | 2.4 T | ? | ||
| Quasi-poloidal stellarator | 2001-2007 | - | Modular | Oak Ridge | Oak Ridge National Laboratory | 0.9 m/0.33 m | 1.0 T | Stellarator research | ||
| NCSX | 2004-2008 | - | Helias | Princeton | Princeton Plasma Physics Laboratory | 1.4 m/0.32 m | 1.7 T | High-β stability | ||
| Compact Toroidal Hybrid | ? | 2007?- | Torsatron | Auburn | Auburn University | 0.75 m/0.2 m | 0.7 T | Hybrid stellarator/tokamak | ||
| HIDRA | 2013-2014 | 2014- | ? | Urbana, IL | University of Illinois | 0.72 m/0.19 m | 0.5 T | Stellarator and Tokamak in one device | ||
| UST_2 | 2013 | 2014- | modular three period quasi-isodynamic | Madrid | Charles III University of Madrid | 0.29 m/0.04 m | 0.089 T | 3D printed stellarator | ||
| Wendelstein 7-X | 1996-2015 | 2015- | Helias | Greifswald | Max-Planck-Institut für Plasmaphysik | 5.5 m/0.53 m | 3 T | Steady-state plasma in fully optimized stellarator | ||
| SCR-1 | 2011-2015 | 2016- | Modular | Cartago  | Instituto Tecnológico de Costa Rica | 0.14 m/0.042 m | 0.044 T |
Reversed field pinch (RFP)
- ETA-BETA II in Padua, Italy
- RFX, Consorzio RFX, Padova, Italy
- MST, University of Wisconsin–Madison, United States
- T2R, Royal Institute of Technology, Stockholm, Sweden
- TPE-RX, AIST, Tsukuba, Japan
- KTX in China
[Magnetic mirror]
- Baseball I/Baseball II Lawrence Livermore National Laboratory, Livermore CA.
- TMX, TMX-U Lawrence Livermore National Laboratory, Livermore CA.
- MFTF Lawrence Livermore National Laboratory, Livermore CA.
- Gas Dynamic Trap at Budker Institute of Nuclear Physics, Akademgorodok, Russia.
[Spheromak]
- Sustained Spheromak Physics Experiment
[Field-Reversed Configuration] (FRC)
- C-2 Tri Alpha Energy
- C-2U Tri Alpha Energy
- C-2W TAE Technologies
- LSX University of Washington
- IPA University of Washington
- HF University of Washington
- IPA- HF University of Washington
Open field lines
Plasma pinch">Pinch (plasma physics)">Plasma pinch
- Trisops - 2 facing theta-pinch guns
[Levitated Dipole]
- Levitated Dipole Experiment, MIT/Columbia University, United States
Inertial confinement
Laser-driven
Current or under construction experimental facilities
Solid state lasers
- National Ignition Facility at LLNL in California, US
- Laser Mégajoule of the Commissariat à l'Énergie Atomique in Bordeaux, France
- OMEGA EL Laser at the Laboratory for Laser Energetics, Rochester, US
- Gekko XII at the Institute for Laser Engineering in Osaka, Japan
- ISKRA-4 and ISKRA-5 Lasers at the Russian Federal Nuclear Center VNIIEF
- Pharos laser, 2 beam 1 kJ/pulse Nd:Glass laser at the Naval Research Laboratories
- Vulcan laser at the central Laser Facility, Rutherford Appleton Laboratory, 2.6 kJ/pulse Nd:glass laser
- Trident laser, at LANL; 3 beams total; 2 x 400 J beams, 100 ps – 1 us; 1 beam ~100 J, 600 fs – 2 ns.
Gas lasers
- NIKE laser at the Naval Research Laboratories, Krypton Fluoride gas laser
- PALS, formerly the "Asterix IV", at the Academy of Sciences of the Czech Republic, 1 kJ max. output iodine laser at 1.315 micrometre fundamental wavelength
Dismantled experimental facilities
Solid-state lasers
- 4 pi laser built during the mid 1960s at Lawrence Livermore National Laboratory
- Long path laser built at LLNL in 1972
- The two beam Janus laser built at LLNL in 1975
- The two beam Cyclops laser built at LLNL in 1975
- The two beam Argus laser built at LLNL in 1976
- The 20 beam Shiva laser built at LLNL in 1977
- 24 beam OMEGA laser completed in 1980 at the University of Rochester's Laboratory for Laser Energetics
- The 10 beam Nova laser at LLNL.
Gas lasers
- "Single Beam System" or simply "67" after the building number it was housed in, a 1 kJ carbon dioxide laser at Los Alamos National Laboratory
- Gemini laser, 2 beams, 2.5 kJ carbon dioxide laser at LANL
- Helios laser, 8 beam, ~10 kJ carbon dioxide laser at LANL — :commons:Category:Helios laser, Los Alamos National Laboratory|Media at Wikimedia Commons
- Antares laser at LANL.
- Aurora laser 96 beam 1.3 kJ total krypton fluoride laser at LANL
- Sprite laser few joules/pulse laser at the Central Laser Facility, Rutherford Appleton Laboratory
Z-Pinch
- Z Pulsed Power Facility
- ZEBRA device at the University of Nevada's Nevada Terawatt Facility
- Saturn accelerator at Sandia National Laboratory
- MAGPIE at Imperial College London
- COBRA at Cornell University
- PULSOTRON
Inertial electrostatic confinement
- Fusor
- Polywell
Magnetized target fusion
- FRX-L
- FRCHX
- General Fusion - under development
- LINUS project