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.

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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 10¹⁸ to 10²² m⁻³ and the linear dimensions in the range of 0.1 to 10 m. 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 10³¹ to 10³³ m⁻³ 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 10⁴ 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.

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 (and thereby optimize) 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 (RFP), 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^[1]

More information Device name, Status ...

Device name	Status	Construction	Operation	Location	Organisation	Major/minor radius	B-field	Plasma current	Purpose	Image
T-1 (Tokamak-1)[2]	Shut down	1957	1958–1959	Moscow	Kurchatov Institute	0.625 m/0.13 m	1 T	0.04 MA	First tokamak
T-2 (Tokamak-2)[2]	Recycled →FT-1	1959	1960–1970	Moscow	Kurchatov Institute	0.62 m/0.22 m	1 T	0.04 MA
T-3 (Tokamak-3)[2]	Shut down	1960	1962–?	Moscow	Kurchatov Institute	1 m/0.12 m	3.5 T	0.15 MA	Overcame Bohm diffusion by a factor of 10, temperature 10 MK, confinement time 10 ms
T-5 (Tokamak-5)[2]	Shut down	?	1962–1970	Moscow	Kurchatov Institute	0.625 m/0.15 m	1.2 T	0.06 MA	Investigation of plasma equilibrium in vertical and horizontal direction
TM-1	Shut down	?	?	Moscow	Kurchatov Institute
TM-2	Shut down	?	1965	Moscow	Kurchatov Institute
TM-3	Shut down	?	1970	Moscow	Kurchatov Institute
FT-1[2]	Recycled →CASTOR	T-2	1972–2002	Saint Petersburg	Ioffe Institute	0.62 m/0.22 m	1.2 T	0.05 MA
ST (Symmetric Tokamak)	Shut down	Model C	1970–1974	Princeton	Princeton Plasma Physics Laboratory	1.09 m/0.13 m	5.0 T	0.13 MA	First American tokamak, converted from Model C stellarator
T-6 (Tokamak-6)	Shut down	?	1970–1974	Moscow	Kurchatov Institute	0.7 m/0.25 m	1.5 T	0.22 MA
TUMAN-2, 2A	Shut down	?	1971–1985	Saint Petersburg	Ioffe Institute	0.4 m/0.08 m	1.5 T	0.012 MA
ORMAK (Oak Ridge tokaMAK)	Shut down		1971–1976	Oak Ridge	Oak Ridge National Laboratory	0.8 m/0.23 m	2.5 T	0.34 MA	First to achieve 20 MK plasma temperature
Doublet II	Shut down		1972–1974	San Diego	General Atomics	0.63 m/0.08 m	0.95 T	0.21 MA
ATC (Adiabatic Toroidal Compressor)	Shut down	1971–1972	1972–1976	Princeton	Princeton Plasma Physics Laboratory	0.88 m/0.11 m	2 T	0.05 MA	Demonstrate compressional plasma heating
T-9 (Tokamak-9)	Shut down	?	1972–1977	Moscow	Kurchatov Institute	0.36 m/0.07 m	1 T
TO-1	Shut down	?	1972–1978	Moscow	Kurchatov Institute	0.6 m/0.13 m	1.5 T	0.07 MA
Alcator A (Alto Campo Toro)	Shut down	?	1972–1978	Cambridge	Massachusetts Institute of Technology	0.54 m/0.10 m	9.0 T	0.3 MA
JFT-2 (JAERI Fusion Torus 2)	Shut down	?	1972–1982	Naka	Japan Atomic Energy Research Institute	0.9 m/0.25 m	1.8 T	0.25 MA
Turbulent Tokamak Frascati (TTF, torello)	Shut down		1973	Frascati	ENEA	0.3 m/0.04 m	1 T	0.005 MA	Study of turbulent plasma heating
Pulsator[3]	Shut down	1970–1973	1973–1979	Garching	Max Planck Institute for Plasma Physics	0.7 m/0.12 m	2.7 T	0.125 MA	Discovery of high-density operation with tokamaks
TFR (Tokamak de Fontenay-aux-Roses)	Shut down		1973–1984	Fontenay-aux-Roses	CEA	0.98 m/0.2 m	6 T	0.49 MA
T-4 (Tokamak-4)[2]	Shut down	?	1974–1978	Moscow	Kurchatov Institute	0.9 m/0.16 m	5 T	0.3 MA	Observed fast thermal quench before major plasma disruptions
Doublet IIA	Shut down		1974–1979	San Diego	General Atomics	0.66 m/0.15 m	0.76 T	0.35 MA
Petula-B	Shut down	?	1974–1986	Grenoble	CEA	0.72 m/0.18 m	2.7 T	0.23 MA
T-10 (Tokamak-10)[2]	Operational		1975–	Moscow	Kurchatov Institute	1.50 m/0.37 m	4 T	0.8 MA	Largest tokamak of its time
T-11 (Tokamak-11)	Shut down	?	1975–1984	Moscow	Kurchatov Institute	0.7 m/0.25 m	1 T
PLT (Princeton Large Torus)	Shut down	1972–1975	1975–1986	Princeton	Princeton Plasma Physics Laboratory	1.32 m/0.42 m	4 T	0.7 MA	First to achieve 1 MA plasma current
Divertor Injection Tokamak Experiment (DITE)	Shut down		1975–1989	Culham	United Kingdom Atomic Energy Authority	1.17 m/0.27 m	2.7 T	0.26 MA
JIPP T-II	Shut down	?	1976	Nagoya	Nagoya University	0.91 m/0.17 m	3 T	0.16 MA
TNT-A	Shut down	?	1976	Tokyo	Tokyo University	0.4 m/0.09 m	0.42 T	0.02 MA
T-8 (Tokamak-8)[2]	Shut down	?	1976–?	Moscow	Kurchatov Institute	0.28 m/0.048 m	0.9 T	0.024 MA	First D-shaped tokamak
Microtor[4]	Shut down	?	1976–1983?	Los Angeles	UCLA	0.3 m/0.1 m	2.5 T	0.12 MA	Plasma impurity control and diagnostic development
Macrotor[4]	Shut down	?	1970s–80s	Los Angeles	UCLA	0.9 m/0.4 m	0.4 T	0.1 MA	Understanding plasma rotation driven by radial current
TUMAN-3[2]	Operational	?	1977– (1990–, 3M)	Saint Petersburg	Ioffe Institute	0.55 m/0.23 m	3 T	0.18 MA	Study adiabatic compression, RF and NB heating, H-mode and parametric instability
Thor[5]	Shut down		?	Milano	University of Milano	0.52 m/0.195 m	1 T	0.055 MA
FT (Frascati Tokamak)	Shut down		1978	Frascati	ENEA	0.83 m/0.20 m	10 T	0.8 MA
PDX (Poloidal Divertor Experiment)	Shut down	?	1978–1983	Princeton	Princeton Plasma Physics Laboratory	1.4 m/0.4 m	2.4 T	0.5 MA
ISX-B	Shut down	?	1978–1984	Oak Ridge	Oak Ridge National Laboratory	0.93 m/0.27 m	1.8 T	0.2 MA	Superconducting coils, attempt high-beta operation
Doublet III	Shut down		1978–1985	San Diego	General Atomics	1.45 m/0.45 m	2.6 T	0.61 MA
T-12 (Tokamak-12)	Shut down	?	1978–1985	Moscow	Kurchatov Institute	0.36 m/0.08 m	1 T	0.03 MA
Alcator C (Alto Campo Toro)	Shut down	?	1978–1986	Cambridge	Massachusetts Institute of Technology	0.64 m/0.16 m	13 T	0.8 MA
T-7 (Tokamak-7)[2]	Recycled →HT-7[6]	?	1979–1985	Moscow	Kurchatov Institute	1.2 m/0.31 m	3 T	0.3 MA	First tokamak with superconducting toroidal field coils
ASDEX (Axially Symmetric Divertor Experiment)[7]	Recycled →HL-2A	1973–1980	1980–1990	Garching	Max-Planck-Institut für Plasmaphysik	1.65 m/0.4 m	2.8 T	0.5 MA	Discovery of the H-mode in 1982
FT-2[2]	Operational	?	1980–	Saint Petersburg	Ioffe Institute	0.55 m/0.08 m	3 T	0.05 MA	H-mode physics, LH heating
TEXTOR (Tokamak Experiment for Technology Oriented Research)[8][9]	Shut down	1976–1980	1981–2013	Jülich	Forschungszentrum Jülich	1.75 m/0.47 m	2.8 T	0.8 MA	Study plasma-wall interactions
TFTR (Tokamak Fusion Test Reactor)[10]	Shut down	1980–1982	1982–1997	Princeton	Princeton Plasma Physics Laboratory	2.4 m/0.8 m	5.9 T	3 MA	Attempted scientific break-even, reached record fusion power of 10.7 MW and temperature of 510 MK
JFT-2M (JAERI Fusion Torus 2M)	Shut down	?	1983–2004	Naka	Japan Atomic Energy Research Institute	1.3 m/0.35 m	2.2 T	0.5 MA
JET (Joint European Torus)[11]	Shut down	1978–1983	1983–2023	Culham	United Kingdom Atomic Energy Authority	2.96 m/0.96 m	4 T	7 MA	Records for fusion output power 16.1 MW (1997), fusion energy 69 MJ (2023)
Novillo[12][13]	Shut down	NOVA-II	1983–2004	Mexico City	Instituto Nacional de Investigaciones Nucleares	0.23 m/0.06 m	1 T	0.01 MA	Study plasma-wall interactions
JT-60 (Japan Torus-60)[14]	Recycled →JT-60SA		1985–2010	Naka	Japan Atomic Energy Research Institute	3.4 m/1.0 m	4 T	3 MA	High-beta steady-state operation, highest fusion triple product
CCT (Continuous Current Tokamak)	Shut down	?	1986–199?	Los Angeles	UCLA	1.5 m/0.4 m	0.2 T	0.05 MA	H-mode studies
DIII-D[15]	Operational	1986[16]	1986–	San Diego	General Atomics	1.67 m/0.67 m	2.2 T	3 MA	Tokamak Optimization
STOR-M (Saskatchewan Torus-Modified)[17]	Operational		1987–	Saskatoon	Plasma Physics Laboratory (Saskatchewan)	0.46 m/0.125 m	1 T	0.06 MA	Study plasma heating and anomalous transport
T-15[2]	Recycled →T-15MD	1983–1988	1988–1995	Moscow	Kurchatov Institute	2.43 m/0.78 m	3.6 T	1 MA	First superconducting tokamak, pulse duration 1.5 s
Tore Supra[18]	Recycled →WEST		1988–2011	Cadarache	Département de Recherches sur la Fusion Contrôlée	2.25 m/0.7 m	4.5 T	2 MA	Large superconducting tokamak with active cooling
ADITYA (tokamak)	Operational		1989–	Gandhinagar	Institute for Plasma Research	0.75 m/0.25 m	1.2 T	0.25 MA
COMPASS (COMPact ASSembly)[19][20]	Operational	1980–	1989–	Prague	Institute of Plasma Physics AS CR	0.56 m/0.23 m	2.1 T	0.32 MA	Plasma physics studies for ITER
FTU (Frascati Tokamak Upgrade)	Operational		1990–	Frascati	ENEA	0.935 m/0.35 m	8 T	1.6 MA
START (Small Tight Aspect Ratio Tokamak)[21]	Recycled →Proto-Sphera		1990–1998	Culham	United Kingdom Atomic Energy Authority	0.3 m/?	0.5 T	0.31 MA	First full-sized Spherical Tokamak
ASDEX Upgrade (Axially Symmetric Divertor Experiment)	Operational		1991–	Garching	Max-Planck-Institut für Plasmaphysik	1.65 m/0.5 m	2.6 T	1.4 MA
Alcator C-Mod (Alto Campo Toro)[22]	Shut down	1986–	1991–2016	Cambridge	Massachusetts Institute of Technology	0.68 m/0.22 m	8 T	2 MA	Record plasma pressure 2.05 bar
ISTTOK (Instituto Superior Técnico TOKamak)[23]	Operational		1992–	Lisbon	Instituto de Plasmas e Fusão Nuclear	0.46 m/0.085 m	2.8 T	0.01 MA
TCV (Tokamak à Configuration Variable)[24]	Operational		1992–	Lausanne	École Polytechnique Fédérale de Lausanne	0.88 m/0.25 m	1.43 T	1.2 MA	Confinement studies
HBT-EP (High Beta Tokamak-Extended Pulse)	Operational		1993–	New York City	Columbia University Plasma Physics Laboratory	0.92 m/0.15 m	0.35 T	0.03 MA	High-Beta tokamak
HT-7 (Hefei Tokamak-7)	Shut down	1991–1994 (T-7)	1995–2013	Hefei	Hefei Institutes of Physical Science	1.22 m/0.27 m	2 T	0.2 MA	China's first superconducting tokamak
Pegasus Toroidal Experiment[25]	Operational	?	1996–	Madison	University of Wisconsin–Madison	0.45 m/0.4 m	0.18 T	0.3 MA	Extremely low aspect ratio
NSTX (National Spherical Torus Experiment)[26]	Operational		1999–	Plainsboro Township	Princeton Plasma Physics Laboratory	0.85 m/0.68 m	0.3 T	2 MA	Study the spherical tokamak concept
Globus-M (UNU Globus-M)[27]	Operational		1999–	Saint Petersburg	Ioffe Institute	0.36 m/0.24 m	0.4 T	0.3 MA	Study the spherical tokamak concept
ET (Electric Tokamak)	Recycled →ETPD	1998	1999–2006	Los Angeles	UCLA	5 m/1 m	0.25 T	0.045 MA	Largest tokamak of its time
TCABR (Tokamak Chauffage Alfvén Brésilien)	Operational	1980–1999	1999–	Lausanne, Sao Paulo	University of Sao Paulo	0.615 m / 0.18 m	1.1 T	0.10 MA	Most important tokamak in the southern hemisphere
CDX-U (Current Drive Experiment-Upgrade)	Recycled →LTX		2000–2005	Princeton	Princeton Plasma Physics Laboratory	0.3 m/?	0.23 T	0.03 MA	Study Lithium in plasma walls
MAST (Mega-Ampere Spherical Tokamak)[28]	Recycled →MAST-Upgrade	1997–1999	2000–2013	Culham	United Kingdom Atomic Energy Authority	0.85 m/0.65 m	0.55 T	1.35 MA	Investigate spherical tokamak for fusion
HL-2A (Huan-Liuqi-2A)	Operational	2000–2002	2002–2018	Chengdu	Southwestern Institute of Physics	1.65 m/0.4 m	2.7 T	0.43 MA	H-mode physics, ELM mitigation
SST-1 (Steady State Superconducting Tokamak)[29]	Operational	2001–	2005–	Gandhinagar	Institute for Plasma Research	1.1 m/0.2 m	3 T	0.22 MA	Produce a 1000 s elongated double null divertor plasma
EAST (Experimental Advanced Superconducting Tokamak)[30]	Operational	2000–2005	2006–	Hefei	Hefei Institutes of Physical Science	1.85 m/0.43 m	3.5 T	0.5 MA	Superheated plasma for over 101 s at 120 M°C and 20 s at 160 M°C[31]
J-TEXT (Joint TEXT)	Operational	TEXT (Texas EXperimental Tokamak)	2007–	Wuhan	Huazhong University of Science and Technology	1.05 m/0.26 m	2.0 T	0.2 MA	Develop plasma control
KSTAR (Korea Superconducting Tokamak Advanced Research)[32]	Operational	1998–2007	2008–	Daejeon	National Fusion Research Institute	1.8 m/0.5 m	3.5 T	2 MA	Tokamak with fully superconducting magnets, 48 s-long operation at 100 MK[33]
LTX (Lithium Tokamak Experiment)	Operational	2005–2008	2008–	Princeton	Princeton Plasma Physics Laboratory	0.4 m/?	0.4 T	0.4 MA	Study Lithium in plasma walls
QUEST (Q-shu University Experiment with Steady-State Spherical Tokamak)[34]	Operational		2008–	Kasuga	Kyushu University	0.68 m/0.4 m	0.25 T	0.02 MA	Study steady state operation of a Spherical Tokamak
Kazakhstan Tokamak for Material testing (KTM)	Operational	2000–2010	2010–	Kurchatov	National Nuclear Center of the Republic of Kazakhstan	0.86 m/0.43 m	1 T	0.75 MA	Testing of wall and divertor
ST25-HTS[35]	Operational	2012–2015	2015–	Culham	Tokamak Energy Ltd	0.25 m/0.125 m	0.1 T	0.02 MA	Steady state plasma
WEST (Tungsten Environment in Steady-state Tokamak)	Operational	2013–2016	2016–	Cadarache	Département de Recherches sur la Fusion Contrôlée	2.5 m/0.5 m	3.7 T	1 MA	Superconducting tokamak with active cooling
ST40[36]	Operational	2017–2018	2018–	Didcot	Tokamak Energy Ltd	0.4 m/0.3 m	3 T	2 MA	First high field spherical tokamak
MAST-U (Mega-Ampere Spherical Tokamak Upgrade)[37]	Operational	2013–2019	2020–	Culham	United Kingdom Atomic Energy Authority	0.85 m/0.65 m	0.92 T	2 MA	Test new exhaust concepts for a spherical tokamak
HL-2M (Huan-Liuqi-2M)[38]	Operational	2018–2019	2020–	Leshan	Southwestern Institute of Physics	1.78 m/0.65 m	2.2 T	1.2 MA	Elongated plasma with 200 MK
JT-60SA (Japan Torus-60 super, advanced)[39]	Operational	2013–2020	2021–	Naka	Japan Atomic Energy Research Institute	2.96 m/1.18 m	2.25 T	5.5 MA	Optimise plasma configurations for ITER and DEMO with full non-inductive steady-state operation
T-15MD	Operational	2010–2020	2021–	Moscow	Kurchatov Institute	1.48 m/0.67 m	2 T	2 MA	Hybrid fusion/fission reactor
ITER[40]	Under construction	2013–2025?	2025?	Cadarache	ITER Council	6.2 m/2.0 m	5.3 T	15 MA ?	Demonstrate feasibility of fusion on a power-plant scale with 500 MW fusion power
SPARC[41][42][43][44][45]	Under construction	2021–	2025	Devens, MA	Commonwealth Fusion Systems and MIT Plasma Science and Fusion Center	1.85 m/0.57 m	12.2 T	8.7 MA	Compact, high-field tokamak with ReBCO coils and 100 MW planned fusion power
DTT (Divertor Tokamak Test facility)[46][47]	Planned	2022–2027?	2027?	Frascati	ENEA	2.14 m/0.70 m	6 T ?	5.5 MA ?	Superconducting tokamak to study power exhaust
SST-2 (Steady State Tokamak-2)[48]	Planned		2027?	Gujarat	Institute for Plasma Research	4.42 m/1.47 m	5.42 T	11.2 MA	Full-fledged fusion reactor with tritium breeding and up to 500 MW output
CFETR (China Fusion Engineering Test Reactor)[49]	Planned	≥2023	2030?		Institute of Plasma Physics, Chinese Academy of Sciences	7.2 m/2.2 m ?	6.5 T ?	14 MA ?	Bridge gaps between ITER and DEMO, planned fusion power 1000 MW
ST-F1 (Spherical Tokamak - Fusion 1)[50]	Planned	2027?		Didcot	Tokamak Energy Ltd	1.4 m/0.8 m ?	4 T	5 MA	Spherical tokamak with Q=3 and hundreds of MW planned electrical output
STEP (Spherical Tokamak for Energy Production)	Planned	2032-2040	2040 D-D Mid 2040s DT Campaign	West Burton, Nottinghamshire	United Kingdom Atomic Energy Authority	3 m/2 m ?	?	16.5 MA ?	Spherical tokamak with 100MW planned electrical output	[51]
IGNITOR[52]	Planned[53]	?	?	Troitzk	ENEA	1.32 m/0.47 m	13 T	11 MA ?	Compact fusion reactor with self-sustained plasma and 100 MW of planned fusion power
JA-DEMO	Planned	2030?	2050?		?	8.5 m/2.4 m[54]	5.94 T	12.3 MA	Prototype for development of Commercial Fusion Reactors 1.5-2GW Fusion output.[55]
K-DEMO (Korean fusion demonstration tokamak reactor)[56]	Planned	2037?			National Fusion Research Institute	6.8 m/2.1 m	7 T	12 MA ?	Prototype for the development of commercial fusion reactors with around 2200 MW of fusion power
DEMO (DEMOnstration Power Station)	Planned	2040?	2050?	?		9 m/3 m ?	6 T ?	20 MA ?	Prototype for a commercial fusion reactor

Close

Stellarator

More information Device name, Status ...

Device name	Status	Construction	Operation	Type	Location	Organisation	Major/minor radius	B-field	Purpose	Image
Model A	Shut down	1952–1953	1953–?	Figure-8	Princeton	Princeton Plasma Physics Laboratory	0.3 m/0.02 m	0.1 T	First stellarator, table-top device
Model B	Shut down	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	Shut down		?–1959	Figure-8	Princeton	Princeton Plasma Physics Laboratory	0.25 m/0.02 m	5 T	Yielded 1 MK plasma temperatures, showed cooling by X-ray radiation from impurities
Model B-2	Shut down		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	Shut down	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	Shut down	1955	1955	Square	Princeton	Princeton Plasma Physics Laboratory	? m/0.05 m	1.8 T
Model B-65	Shut down	1957	1957	Racetrack	Princeton	Princeton Plasma Physics Laboratory
Model B-66	Shut down	1958	1958–?	Racetrack	Princeton	Princeton Plasma Physics Laboratory
Wendelstein 1-A	Shut down		1960	Racetrack	Garching	Max-Planck-Institut für Plasmaphysik	0.35 m/0.02 m	2 T	ℓ=3 showed that stellarators can overcome Bohm diffusion, "Munich mystery"
Wendelstein 1-B	Shut down		1960	Racetrack	Garching	Max-Planck-Institut für Plasmaphysik	0.35 m/0.02 m	2 T	ℓ=2
Model C	Recycled →ST	1957–1961	1961–1969	Racetrack	Princeton	Princeton Plasma Physics Laboratory	1.9 m/0.07 m	3.5 T	Suffered from large plasma losses by Bohm diffusion through "pump-out"
L-1	Shut down	1963	1963–1971	round	Moscow	Lebedev Physical Institute	0.6 m/0.05 m	1 T	First Soviet stellarator, overcame Bohm diffusion
SIRIUS	Shut down		1964–?	Racetrack	Kharkiv	Kharkiv Institute of Physics and Technology (KIPT)
TOR-1	Shut down	1967	1967–1973		Moscow	Lebedev Physical Institute	0.6 m/0.05 m	1 T
TOR-2	Shut down	?	1967–1973		Moscow	Lebedev Physical Institute	0.63 m/0.036 m	2.5 T
Uragan-1	Shut down	1960–1967	1967–?	Racetrack	Kharkiv	National Science Center, Kharkiv Institute of Physics and Technology (NSC KIPT)	1.1 m/0.1 m	1 T	Overcame Bohm-diffusion by a factor of 30
CLASP (Closed Line And Single Particle)[57]	Shut down	?	1967–?		Culham	United Kingdom Atomic Energy Authority	0.3 m/0.056 m	0.1 T	Study confinement of electrons in a high-shear stellarator
TWIST[57]	Shut down	?	1967–?		Culham	United Kingdom Atomic Energy Authority	0.32 m/0.045 m	0.3 T	Study turbulent heating
Proto-CLEO[57]	Shut down	?	1968–?	single-turn helical winding inside toroidal field conductors	Culham, Madison	United Kingdom Atomic Energy Authority	0.4 m/0.05 m	0.5 T	confirmed plasma confinement times of neoclassical theory
TORSO[57]	Shut down	?	1972–?	Ultimate torsatron	Culham	United Kingdom Atomic Energy Authority	0.4 m/0.05 m	2 T
CLEO[57]	Shut down	?	1974–?		Culham	United Kingdom Atomic Energy Authority	0.9 m/0.125 m	2 T	Study of particle transport and beta limits, reached similar performance as tokamaks
Wendelstein 2-A	Shut down	1965–1968	1968–1974	Heliotron	Garching	Max-Planck-Institut für Plasmaphysik	0.5 m/0.05 m	0.6 T	Good plasma confinement
Saturn[58]	Shut down	1970	1970–?	Torsatron	Kharkiv	Kharkiv Institute of Physics and Technology	0.36 m/0.08 m	1 T	first Torsatron, ℓ=3, m=8 field periods, base for several torsatrons at KIPT
Wendelstein 2-B	Shut down	?–1970	1971–?	Heliotron	Garching	Max-Planck-Institut für Plasmaphysik	0.5 m/0.055 m	1.25 T	Demonstrated similar performance as tokamaks
Vint-20[59]	Shut down	1972	1973–?	Torsatron	Kharkiv	Kharkiv Institute of Physics and Technology	0.315 m/0.0725 m	1.8 T	single-pole ℓ=1, m=13 field periods
L-2	Shut down	?	1975–?		Moscow	Lebedev Physical Institute	1 m/0.11 m	2.0 T
WEGA (Wendelstein Experiment in Greifswald für die Ausbildung)	Recycled →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	Shut down	?	1975–1985	Classical stellarator	Garching	Max-Planck-Institut für Plasmaphysik	2 m/0.1 m	3.5 T	First "pure" stellarator without plasma current, solved stellarator heating problem
Heliotron-E	Shut down	?	1980–?	Heliotron			2.2 m/0.2 m	1.9 T
Heliotron-DR	Shut down	?	1981–?	Heliotron			0.9 m/0.07 m	0.6 T
Uragan-3 (M [uk])[60]	Operational	?	1982–?[61] M: 1990–	Torsatron	Kharkiv	National Science Center, Kharkiv Institute of Physics and Technology (NSC KIPT)	1.0 m/0.12 m	1.3 T	?
Auburn Torsatron (AT)	Shut down	?	1984–1990	Torsatron	Auburn	Auburn University	0.58 m/0.14 m	0.2 T
Wendelstein 7-AS	Shut down	1982–1988	1988–2002	Modular, advanced stellarator	Garching	Max-Planck-Institut für Plasmaphysik	2 m/0.13 m	2.6 T	First computer-optimized stellarator, first H-mode in a stellarator in 1992
Advanced Toroidal Facility (ATF)	Shut down	1984–1988[62]	1988–1994	Torsatron	Oak Ridge	Oak Ridge National Laboratory	2.1 m/0.27 m	2.0 T	First large American stellarator after Tokamak stampede, high-beta operation, >1h plasma operation
Compact Helical System (CHS)	Shut down	?	1989–?	Heliotron	Toki	National Institute for Fusion Science	1 m/0.2 m	1.5 T
Compact Auburn Torsatron (CAT)	Shut down	?–1990	1990–2000	Torsatron	Auburn	Auburn University	0.53 m/0.11 m	0.1 T	Study magnetic flux surfaces
H-1 (Heliac-1)[63]	Operational		1992–	Heliac	Canberra,	Research School of Physical Sciences and Engineering, Australian National University	1.0 m/0.19 m	0.5 T	shipped to China in 2017
TJ-K (Tokamak de la Junta Kiel)[64]	Operational	TJ-IU (1999)	1994–	Torsatron	Kiel, Stuttgart	University of Stuttgart	0.60 m/0.10 m	0.5 T	One helical and two vertical coil sets; Teaching; moved from Kiel to Stuttgart in 2005
TJ-II (Tokamak de la Junta II)[65]	Operational	1991–1996	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 (Large Helical Device)[66]	Operational	1990–1998	1998–	Heliotron	Toki	National Institute for Fusion Science	3.5 m/0.6 m	3 T	Demonstrated long-term operation of large superconducting coils
HSX (Helically Symmetric Experiment)[67]	Operational		1999–	Modular, quasi-helically symmetric	Madison	University of Wisconsin–Madison	1.2 m/0.15 m	1 T	Investigate plasma transport in quasi-helically-symmetric field, similar to tokamaks
Heliotron J[68]	Operational		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 (CNT)	Operational	?	2004–	Circular interlocked coils	New York City	Columbia University	0.3 m/0.1 m	0.2 T	Study of non-neutral (mostly electron) plasmas
Uragan-2(M)[60]	Operational	1988–2006	2006–[69]	Heliotron, Torsatron	Kharkiv	National Science Center, Kharkiv Institute of Physics and Technology (NSC KIPT)	1.7 m/0.22 m	2.4 T	ℓ=2 Torsatron
Quasi-poloidal stellarator (QPS)[70][71]	Cancelled	2001–2007	–	Modular	Oak Ridge	Oak Ridge National Laboratory	0.9 m/0.33 m	1.0 T	Stellarator research
NCSX (National Compact Stellarator Experiment)	Cancelled	2004–2008	–	Helias	Princeton	Princeton Plasma Physics Laboratory	1.4 m/0.32 m	1.7 T	High-β stability
Compact Toroidal Hybrid (CTH)	Operational	?	2007?–	Torsatron	Auburn	Auburn University	0.75 m/0.2 m	0.7 T	Hybrid stellarator/tokamak
HIDRA (Hybrid Illinois Device for Research and Applications)[72]	Operational	2013–2014 (WEGA)	2014–	?	Urbana, IL	University of Illinois	0.72 m/0.19 m	0.5 T	Stellarator and tokamak in one device, capable of long pulse steady-state operation; study plasma-wall interactions
UST_2[73]	Operational	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[74]	Operational	1996–2022	2015–	Helias	Greifswald	Max-Planck-Institut für Plasmaphysik	5.5 m/0.53 m	3 T	Steady-state plasma in large fully optimized stellarator
SCR-1 (Stellarator of Costa Rica)	Operational	2011–2015	2016–	Modular	Cartago	Costa Rica Institute of Technology	0.14 m/0.042 m	0.044 T
MUSE[75]	Operational	2022–2023	2023–	Quasiaxi-symmetrical	Princeton	Princeton Plasma Physics Laboratory	0.3 m/0.075 m	0.15 T	First stellarator with permanent magnets
CFQS (Chinese First Quasi-Axisymmetric Stellarator)[76]	Under construction	2017–		Helias	Chengdu	Southwest Jiaotong University, National Institute for Fusion Science in Japan	1 m/0.25 m	1 T	m=2 quasi-axisymmetric stellarator, modular
EFPP (European Fusion Power Plant)[77]	Planned	2030 ?	2045 ?	Helias		Gauss Fusion		7–9 T ?	Fusion power plant with 2–3 GW output

Close

Magnetic mirror

• Tabletop/Toytop, Lawrence Livermore National Laboratory, Livermore CA.
• DCX/DCX-2, Oak Ridge National Laboratory
• OGRA (Odin GRAm neitronov v sutki, one gram of neutrons per day), Akademgorodok, Russia. A 20-meter-long pipe
• Baseball I/Baseball II Lawrence Livermore National Laboratory, Livermore CA.
• 2X/2XIII/2XIII-B, 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.

Toroidal Z-pinch

• Perhapsatron (1953, USA)
• ZETA (Zero Energy Thermonuclear Assembly) (1957, United Kingdom)

Reversed field pinch (RFP)

• ETA-BETA II in Padua, Italy (1979–1989)
• RFX (Reversed-Field eXperiment), Consorzio RFX, Padova, Italy^[78]
• MST (Madison Symmetric Torus), University of Wisconsin–Madison, United States^[79]
• T2R, Royal Institute of Technology, Stockholm, Sweden
• TPE-RX, AIST, Tsukuba, Japan
• KTX (Keda Torus eXperiment) in China (since 2015)^[80]

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

Other toroidal machines

• TMP (Tor s Magnitnym Polem, torus with magnetic field): A porcelain torus with major radius 80 cm, minor radius 13 cm, toroidal field of 1.5 T and plasma current 0.25 MA, predecessor to the first tokamak (1955, USSR)

• Fusor
  • List of fusor examples
• Polywell

• FRX-L
• FRCHX
• General Fusion – under development
• LINUS project