Skip to content
FusionBenchmark

Fusion

Fusion releases energy by joining light nuclei. No fusion machine has yet produced more electricity than it used.

A result is a figure measured on a machine: not a design value, a model or a target. Achieved means it was also checked against its source. Gain figures, with what each one divides by, are on gain. Dated plans to sell fusion electricity are in the commercial timeline of fusion power.

Approaches

The hard part is holding fuel hot and dense for long enough. Machines differ in how they do it.

  • Magnetic confinement

    Holding a hot plasma away from material walls using magnetic fields, sustained for seconds to steady-state rather than the nanosecond pulses of inertial confinement. The open problem shared by every configuration below is exhausting the plasma's heat and helium ash without eroding the wall that must survive it for years, not seconds.

    26 companies · 127 devices · includes Tokamak, Stellarator, Magnetic mirror, Field-reversed configuration, Levitated dipole, Reversed-field pinch

  • Inertial confinement

    Compressing fuel so fast that its own inertia holds it together long enough to burn: nanoseconds, not seconds. Every ICF approach shares the same open problem beyond ignition itself: repeating a shot several times a second at low enough cost per shot to run a power plant, which no driver has yet demonstrated.

    12 companies · 9 devices · includes Laser ICF, indirect drive, Laser ICF, direct drive, Heavy-ion ICF, Projectile-driven

  • Magneto-inertial

    Compression of a magnetised plasma; sits between MCF and ICF in density and timescale.

    8 companies · 7 devices · includes Z-pinch, Magnetized target, Pulsed magnetic compression

  • Electrostatic confinement

    Confinement by electric rather than magnetic fields.

    3 companies · 1 device · includes Inertial electrostatic confinement

  • Beam-target

    A beam of fast ions fired into a fuel target that is not itself a hot plasma, such as a gas cell or a solid loaded with deuterium or tritium. As each beam ion ploughs through the target it loses its energy to the target's electrons far faster than it is likely to fuse, so only a tiny fraction of the ions fuse before they stop. The fusion energy returned is a small fraction of the energy spent accelerating the beam, so the approach cannot reach net energy gain however the beam or target is arranged. It is commercially useful anyway, as a compact and reliable source of neutrons for imaging and medical isotope production.

    2 companies · 0 devices

  • Muon-catalysed fusion

    A negative muon temporarily replaces an electron in a D-T (or D-D) molecule, pulling the nuclei roughly 200 times closer together than an electron would, so fusion happens at room temperature without confining a hot plasma at all. Added as its own branch of the fusion tree rather than filed under magnetic or inertial confinement, because it confines nothing: the muon does the work electromagnetically at the molecular scale. No net-energy device has been built: a muon typically catalyses only 100-150 fusions before it is captured by a helium nucleus and lost, and the main open problem is extending that cycle count, or cutting the cost of producing muons, enough to get more energy out than went into making them.

    1 company · 0 devices

The full approach tree

Companies

90 organisations have a commercial fusion role, and 61 of them are developers. 31 of the 40 developers whose fuel is recorded plan to burn deuterium and tritium, two heavy forms of hydrogen.

Grouped by approach. A company working on more than one approach appears under each.

Magnetic confinement 26

Inertial confinement 12

Magneto-inertial 8

Electrostatic confinement 3

Beam-target 2

Muon-catalysed fusion 1

Developers with no approach recorded 11

Fusion developers whose confinement approach is not yet in the record.

Suppliers, investors and others 29

All fusion companies, with filters

Devices

Every fusion machine in the record, by whether it is running, being built or planned, or has stopped.

Operating 89

  • ADITYA-U Tokamak · Institute for Plasma Research · IN
  • ALVAND Tokamak · Atomic Energy Organization of Iran · IR
  • ASDEX UPGRADE Tokamak · Max Planck Institute for Plasma Physics · DE
  • CTH Stellarator · Auburn University · US
  • DAMAVAND Tokamak · Atomic Energy Organization of Iran · IR
  • DIII-D Tokamak · General Atomics · US
  • EGYPTOR Tokamak · Egyptian Atomic Energy Authority · EG
  • ETE Spherical tokamak · National Institute for Space Research · BR
  • EXL-50U Spherical tokamak · ENN Science and Technology Development · CN
  • Experimental Advanced Superconducting Tokamak Tokamak · Institute of Plasma Physics, Chinese Academy of Sciences · CN
  • EXTRAP T2R Reversed-field pinch · KTH Royal Institute of Technology · SE
  • FAT-CM Field-reversed configuration · Nihon University · JP
  • FIRST LIGHT Projectile-driven · First Light Fusion · GB
  • FOCUS FUSION Fusion · LPP Fusion · US
  • FT-2 Tokamak · Ioffe Institute · RU
  • FUZE-Q Z-pinch · Zap Energy · US
  • GAMMA 10/PDX Magnetic mirror · University of Tsukuba · JP
  • GDT Magnetic mirror · Budker Institute of Nuclear Physics · RU
  • GEKKO XII Inertial confinement · Osaka University · JP
  • GLAST-III Spherical tokamak · Pakistan Atomic Energy Commission · PK
  • GLOBUS-M2 Spherical tokamak · Ioffe Institute · RU
  • GOL-NB Magnetic mirror · Budker Institute of Nuclear Physics · RU
  • GOLEM Tokamak · Czech Technical University · CZ
  • GUTTA Spherical tokamak · Saint Petersburg State University · RU
  • HBT-EP Tokamak · Columbia University · US
  • HELIOTRON J Stellarator · Kyoto University · JP
  • HH70 Tokamak · Energy Singularity · CN
  • HIDRA Stellarator · University of Illinois · US
  • HIST Spherical tokamak · University of Hyogo · JP
  • HL-2A Tokamak · Southwestern Institute of Physics · CN
  • HL-2M Tokamak · Southwestern Institute of Physics · CN
  • HSX Stellarator · University of Wisconsin-Madison · US
  • HYBTOK-II Tokamak · Nagoya University · JP
  • IR-T1 Tokamak · Islamic Azad University · IR
  • ISTTOK Tokamak · Instituto Superior Técnico · PT
  • J-TEXT Tokamak · Huazhong University of Science and Technology · CN
  • KSTAR Tokamak · Korea Institute of Fusion Energy · KR
  • KTM Spherical tokamak · Institute of Atomic Energy of National Nuclear Center of the Republic of Kazakhstan · KZ
  • KTX Reversed-field pinch · University of Science and Technology of China · CN
  • LATE Spherical tokamak · Kyoto University · JP
  • LFEX Inertial confinement · Osaka University · JP
  • LIBTOR Tokamak · Tajoura Nuclear Research Centre · LY
  • LMJ Inertial confinement · CEA · FR
  • LTX-β Tokamak · Princeton Plasma Physics Laboratory · US
  • MAST-U Spherical tokamak · UK Atomic Energy Authority · GB
  • MEDUSA-CR Spherical tokamak · Instituto Tecnológico de Costa Rica · CR
  • MST Reversed-field pinch · University of Wisconsin-Madison · US
  • MT-1 Spherical tokamak · Pakistan Atomic Energy Commission · PK
  • National Ignition Facility Laser ICF, indirect drive · Lawrence Livermore National Laboratory · US
  • Norm Field-reversed configuration · TAE Technologies · US
  • NORMAN Field-reversed configuration · TAE Technologies · US
  • NORTH Spherical tokamak · Technical University of Denmark · DK
  • NOVA-FURG Tokamak · Federal University of Espírito Santo · BR
  • OMEGA Laser ICF, direct drive · University of Rochester Laboratory for Laser Energetics · US
  • PEGASUS-III Spherical tokamak · University of Wisconsin-Madison · US
  • PHIX Tokamak · Institute of Science Tokyo · JP
  • POLARIS Field-reversed configuration · Helion Energy · US
  • QUEST Spherical tokamak · Kyushu University · JP
  • RELAX Reversed-field pinch · Kyoto Institute of Technology · JP
  • RT-1 Levitated dipole · The University of Tokyo · JP
  • SCR-1 Stellarator · Instituto Tecnológico de Costa Rica · CR
  • SMART Spherical tokamak · University of Seville · ES
  • SMOLA Magnetic mirror · Budker Institute of Nuclear Physics · RU
  • SST-1 Tokamak · Institute for Plasma Research · IN
  • ST40 Spherical tokamak · Tokamak Energy · GB
  • STOR-M Tokamak · University of Saskatchewan · CA
  • SUNIST-1 Spherical tokamak · Tsinghua University · CN
  • T-11M Tokamak · Troitsk Institute for Innovation and Fusion Research · RU
  • T-15MD Tokamak · National Research Centre Kurchatov Institute · RU
  • TCABR Tokamak · University of São Paulo · BR
  • TCV Tokamak · Swiss Plasma Center · CH
  • TJ-II Stellarator · CIEMAT · ES
  • TJ-K Stellarator · University of Stuttgart · DE
  • TOKASTAR-2 Tokamak · Nagoya University · JP
  • TORIX Magnetic confinement · École Polytechnique · FR
  • TORPEX Magnetic confinement · Swiss Plasma Center · CH
  • TST-2 Spherical tokamak · The University of Tokyo · JP
  • TT-1 Tokamak · Thailand Institute of Nuclear Technology · TH
  • TUMAN-3M Tokamak · Ioffe Institute · RU
  • UH-CTI Magnetic confinement · Kyushu University · JP
  • UH-MCPG1 Magnetic confinement · University of Hyogo · JP
  • URAGAN-2M Stellarator · Institute of Plasma Physics National Science Center · UA
  • URAGAN-3M Stellarator · Institute of Plasma Physics National Science Center · UA
  • UTST Spherical tokamak · The University of Tokyo · JP
  • VEST Spherical tokamak · Seoul National University · KR
  • Wendelstein 7-X Stellarator · Max Planck Institute for Plasma Physics · DE
  • WEST Tokamak · CEA · FR
  • Z Machine Z-pinch · Sandia National Laboratories · US
  • ZEBRA Z-pinch · University of Nevada · US

Commissioning 1

  • JT-60SA Tokamak · National Institutes for Quantum Science and Technology · JP

Under construction 14

  • ATLAS (Marvel Fusion) Inertial confinement · Marvel Fusion · US
  • BEST Tokamak · Institute of Plasma Physics, Chinese Academy of Sciences · CN
  • CAT Magnetic mirror · Budker Institute of Nuclear Physics · RU
  • CFQS Stellarator · Southwest Jiaotong University · CN
  • COMPASS-U Tokamak · Institute of Plasma Physics · CZ
  • DTT Tokamak · ENEA · IT
  • HORNE HYBRID REACTOR Inertial electrostatic confinement · Horne Technologies · US
  • ITER Tokamak · ITER Organization · FR
  • MT-2 Spherical tokamak · Pakistan Atomic Energy Commission · PK
  • NSTX-U Spherical tokamak · Princeton Plasma Physics Laboratory · US
  • PILOT GAMMA PDX-SC Magnetic mirror · University of Tsukuba · JP
  • RFX Reversed-field pinch · Consorzio RFX · IT
  • SPARC Tokamak · Commonwealth Fusion Systems · US
  • SSST Spherical tokamak · Institute for Plasma Research · IN

Planned 20

  • Alpha (Proxima Fusion) Stellarator · Proxima Fusion · DE
  • ARC Tokamak · Commonwealth Fusion Systems · US
  • CFETR Tokamak · CN
  • Da Vinci Field-reversed configuration · TAE Technologies
  • EU-DEMO Tokamak
  • FUSION POWER CORE Magnetized target · Compact Fusion Systems · US
  • GDMT Magnetic mirror · Budker Institute of Nuclear Physics · RU
  • GDMT CORE Magnetic mirror · Budker Institute of Nuclear Physics · RU
  • HB11 Inertial confinement · HB11 Energy · AU
  • HELICITY DRIVE Fusion · Helicity Space · US
  • Infinity One Stellarator · Type One Energy · US
  • Infinity Two Stellarator · Type One Energy · US
  • INNOVEN ENERGY LLC Inertial confinement · Innoven Energy · US
  • MIFTI Z-pinch · Magneto-Inertial Fusion Technologies, Inc. · US
  • PFRC Field-reversed configuration · Princeton Fusion Systems · US
  • PJMIF Magnetized target · Hyperjet Fusion Corporation · US
  • PLATO Tokamak · Kyushu University · JP
  • PST Spherical tokamak · Pakistan Atomic Energy Commission · PK
  • Stellaris Stellarator · Proxima Fusion · DE
  • STEP Spherical tokamak · STEP · GB

Shut down 19

  • Alcator A Tokamak · MIT Plasma Science and Fusion Center
  • Alcator C Tokamak · MIT Plasma Science and Fusion Center
  • ASDEX Tokamak
  • C-Mod Tokamak
  • CFR Magnetic mirror · Lockheed Martin · US
  • EXL-50 Spherical tokamak · ENN Science and Technology Development · CN
  • FTU Tokamak · ENEA · IT
  • IDCD Magnetic confinement · CTFusion · US
  • JT-60U Tokamak · JAEA · JP
  • Large Helical Device Stellarator · National Institute for Fusion Science · JP
  • MAST Spherical tokamak
  • NSTX Spherical tokamak
  • PLT Tokamak
  • ST Tokamak
  • START Spherical tokamak
  • T-3 Tokamak
  • TFR Tokamak
  • Tokamak Fusion Test Reactor Tokamak · Princeton Plasma Physics Laboratory · US
  • TRENTA Field-reversed configuration · Helion Energy · US

Decommissioned 1

Cancelled 1

  • COPERNICUS Field-reversed configuration · TAE Technologies · US

Status not recorded 1

  • FuZE Z-pinch · Zap Energy · US

All devices, with their dimensions

Guides

  • How fusion works What nuclear fusion is, which fuels it can use, the temperature, density and confinement it needs, and why no machine has yet turned it into electricity.
  • Fusion approaches compared Every family of fusion machine, how each holds its fuel, the best result this dataset holds for it, its main unsolved problem and the organisations pursuing it.
  • Fusion fuels, tritium and neutrons Deuterium-tritium, deuterium-deuterium, deuterium-helium-3 and proton-boron-11 compared: what each reaction releases, where the fuel comes from, and why aneutronic is a relative term.
  • Fusion milestones: what has happened and what is promised The milestones that mark progress towards fusion power, which have been reached and when, and what fusion organisations say they will do next, in their own words.
  • Commercial timeline of fusion power Six fusion power plants are on record, all still planned. The only dated electricity purchase is Helion's May 2023 deal to supply Microsoft from 2028.

All guides