General Fusion

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General Fusion
TypePrivately held company
IndustryFusion Power
Founded2002; 19 years ago (2002)
FounderMichel Laberge
Key people
Number of employees

General Fusion is a Canadian company based in Burnaby, British Columbia, which is developing a fusion power device based on magnetized target fusion (MTF). The company is funded by a variety of investors.

Most MTF systems use magnets to compress a plasma.[1] In contrast, the General Fusion fusion device under development injects a plasma mass, in the form of a compact toroid as the magnetized target, into a spinning vortex of liquid metal forming a hollow cylinder, which is then mechanically compressed to fusion-relevant densities and pressures, by anywhere from a dozen to hundreds (in various designs) of steam-driven pistons.[2][3][4] As of 2017, General Fusion was developing subsystems for use in a prototype to be built in three to five years.[5] A year later, it was developing a prototype by 2022.[6]

In 2018, the firm published several papers on a new design using a spherical tokamak as the plasma magnetized target, instead of a compact toroid. In extant references, it is unclear if this represents a major change of the original concept.[7]


As of 2016, the firm had 65 employees[8] and had raised over C$150 million in funding from a global syndicate of investors.[9][10] The firm was founded in 2002 by former Creo Products senior physicist and principal engineer Michel Laberge.[11]

The firm is led by a management team consisting of Christofer M. Mowry, chief executive officer (CEO), Bruce Colwill, chief financial officer (CFO), Michel Laberge, chief scientific officer (CSO), and Michael Delage, chief technology officer (CTO).[12]

Michel Laberge founded the firm in 2002. He earned a Doctor of Philosophy (Ph.D.) in physics from the University of British Columbia in 1990, and completed research at the École Polytechnique and the National Research Council of Canada. Before founding General Fusion, Laberge was a senior physicist and principal engineer at Creo Products for nine years.[12]

Christofer Mowry came from a position as the CEO and Chairman of General Synfuels International. Before that, he founded and ran Generation mPower, a company that sold small modular reactors (SMRs), a nuclear energy technology. He served as President of Babcock & Wilcox (B&W) Nuclear Energy and chief operating officer (COO) of WSI.[12]

Michael Delage holds multiple responsibilities at General Fusion, including building partnerships with international research institutions, and overseeing partnerships with governments and other companies, and technology development strategy. Formerly, he cofounded residential demand response technology company Energate, Inc. He also worked as a design engineer on robotic systems for the International Space Station (ISS).[12]

The board of directors is chaired by Frederick W. Buckman Sr., former CEO of Consumers Power.[13] Advising the board is a Scientific Advisory Committee, which includes Carol M. Browner,[14] physicist T. Kenneth Fowler,[8] and former astronaut Mark Kelly.[15]


Diagram of the General Fusion power plant

Power plant design[edit]

General Fusion's magnetized target fusion system uses a ~3 meter sphere filled with a mix of molten liquid metals lead and lithium. The liquid is spun to open up a vertical cylindrical cavity in the centre of the sphere (vortex). This vortex flow is established and maintained by an external pumping system; liquid flows into the sphere through tangentially directed ports at the equator and exits radially through ports near the poles of the sphere.[16]

Attached to the top of the sphere is a plasma injector, from which a pulse of magnetically-confined deuterium-tritium plasma fuel is injected into the center of the vortex. A few milligrams of gas are used per pulse, and the gas is ionized by a bank of capacitors to form a spheromak plasma (self-confined magnetized plasma rings) composed of the deuterium–tritium fuel.[17][18] The firm demonstrated plasma lifetimes up to 2 milliseconds and electron temperatures in excess of 400 eV (4,800,000 degrees C).[19]

The outside of the sphere is covered with steam pistons, which push the liquid metal and collapse the vortex, thereby compressing the plasma. The compression increases the density and temperature of the plasma to the range where the deuterium and tritium nuclei fuse, releasing energy in the form of fast neutrons and alpha particles.[18]

This energy heats up the liquid metal, which is then pumped through a heat exchanger and used to generate electricity via a steam turbine. The plasma forming and compressing process repeats and the liquid metal is continuously pumped through the system. Some of the steam is recycled to power the pistons.[20][16]

An earlier concept used steam pistons to simultaneously impact a set of stationary anvils on the surface of the sphere to create acoustic pressure waves in the liquid metal.[18] The pressure waves would converge to become a spherical shockwave at the center of the sphere. This approach created excessively strong magnetic fields, which caused instabilities in the liquid metal wall. As of October 2017, the approach was to use slower pistons and compression time of 40 ms for lower peak energy densities.[21]

In addition to its role in compressing the plasma, the use of a liquid metal liner shields the power plant structure from neutrons released by the deuterium-tritium fusion reaction, overcoming the problem of structural damage to plasma-facing materials.[22][16] The use of liquid lithium in the mixture enables the breeding of tritium fuel, while the liquid metal provides a means of extracting the energy from the system via a heat exchanger.[16][23]


General Fusion's approach is based on the LINUS concept developed by the United States Naval Research Laboratory (NRL) beginning in 1972.[24][25][26] Researchers at NRL suggested an approach that retains many of the advantages of liner compression to achieve small, high-energy-density fusion, while using a liquid metal as the liner to avoid neutron damage to the tokamak first wall.[27]

In the LINUS concept, a rotating liquid lithium liner is imploded mechanically, using high pressure helium as the energy source. The liner acts as a cylindrical piston to compress a magnetically-confined plasma adiabatically to fusion temperature and relatively high density (~1017−3).[24] In the subsequent expansion the plasma energy and the fusion energy carried by trapped alpha particles is directly recovered, making the mechanical cycle self-sustaining. The LINUS reactor can thus be regarded as a fusion engine, except that there is no shaft output: all the energy appears as heat.[24]

The liquid metal acts as both a compression mechanism and heat transfer mechanism, allowing the energy from the fusion reaction to be captured as heat.[24] LINUS researchers anticipated that the liner could also be used to breed tritium fuel for the power plant, and would protect the machine from high-energy neutrons by acting as a regenerative first wall.[24]

Synchronizing the timing of the compression system was not possible with the technology of the time, and the proposed design was never built.[26] General Fusion's Chief Scientist, Michel Laberge, claimed that these timing limits can now be overcome.[8]

Research and development[edit]

The firm developed the subsystems of the power plant, including plasma injectors and compression driver technology.[28] Patents were awarded for a fusion energy reactor design,[29] and enabling technologies such as plasma accelerators,[30] methods for creating liquid metal vortexes[31] and lithium evaporators.[32]

Plasma injectors[edit]

Plasma injector

Plasma injectors provide the fuel supply for the MTF power plant, injecting a deuterium-tritium plasma into the compression chamber.[33]

Compact toroid plasmas are formed by a coaxial Marshal gun (a type of plasma railgun), with magnetic fields supported by internal plasma currents and eddy currents in the flux conserver wall.[34] The firm has built and operated more than a dozen plasma injectors.[35] These include large two-stage injectors with formation and magnetic acceleration sections (dubbed "PI" experiments), and three generations of smaller, single-stage formation-only injectors (MRT, PROSPECTOR and SPECTOR).[19] In 2016, the firm published research demonstrating spheromak plasma lifespans of up to 2 milliseconds and temperatures in excess of 400 eV on its SPECTOR generation of injectors.[19] As of December 2017, the PI3 plasma injector was operational and held the title as the world's most powerful plasma injector, ten times more powerful than its predecessor.[36]

Compression driver technology[edit]

Pistons for plasma compression

Pneumatic pistons were initially used to create a converging spherical wave to compress the plasma. Each system consists of a 100 kg, 30 cm diameter hammer piston driven down a 1 m long bore by compressed air.[37][18] The hammer piston strikes an anvil at the end of the bore, generating a large amplitude acoustic pulse that is transmitted to the liquid metal in the compression chamber via the piston anvil.[37] To create a spherical wave, the timing of these strikes must be controlled to within 10 µs of each other. The firm has recorded sequences of consecutive shots with impact velocities of 50 m/s and timing synchronized within 2 µs.[37]

A proof-of-concept prototype compression system was constructed in 2013 with 14 full size pistons around 1 meter diameter spherical compression chamber to demonstrate pneumatic compression and collapse of a liquid metal vortex.[38][37]

Liquid metal systems[edit]

The proof-of-concept prototype compression system incorporates technology for forming a vortex of liquid metal as would be required in an MTF power plant. This consists of a 15 tonne liquid lead reservoir, pumped at 100 kg/s to form a vortex inside a 1-meter diameter spherical compression chamber.[38][37]

Research collaborations[edit]

  • Microsoft: In May 2017 General Fusion and Microsoft announced a collaboration to develop a data science platform based on Microsoft's Azure cloud computing system. A second phase of the project was to apply machine learning to the data, with the goal of discovering insights into the behavior of high temperature plasmas. The new computational program would enable General Fusion to mine over 100 terabytes of data from the records of over 150,000 experiments. It will use this data to optimize the designs of their fusion system's plasma injector, piston array, and fuel chamber. During this collaboration, the Microsoft Develop Experience Team was to contribute their experience and resources in machine learning, data management, and cloud computing.[39]
  • Los Alamos National Laboratory: General Fusion entered a cooperative research and development agreement (CRADA) with the U.S. Department of Energy's Los Alamos National Laboratory for magnetized target fusion research.[40]
  • McGill University: McGill University and General Fusion acquired an Engage Grant from the Natural Sciences and Engineering Research of Canada to study General Fusion's Magnetized Target Fusion technology. Specifically, the project was to use McGill's diagnostic abilities to develop techniques to understand the behavior of the liquid metal wall during plasma compression and how it may affect the plasma.[41]
  • Princeton Plasma Physics Laboratory: MHD simulation of compression during MTF experiments[42]
  • Queen Mary University of London: General Fusion funded a research study on high fidelity simulations of non-linear sound propagation in multiphase media of nuclear fusion reactor pursued using QMUL CLithium and Y codes.[43]
  • Hatch Ltd: General Fusion and Hatch Ltd. joined in 2015 to create a fusion energy demonstration system. The project aimed to construct and demonstrate, at power plant scale, the primary subsystems and physics underpinning General Fusion's technology, including their proprietary Magnetized Target Fusion (MTF) technology. Simulation models will be used to verify that this fusion energy system is commercially and technically viable at scale.[28]


General Fusion receives funding through a variety of investors, including Chrysalix venture capital, the Business Development Bank of Canada—a Canadian federal Crown corporation, Bezos Expeditions, Cenovus Energy, Pender Ventures, Khazanah Nasional—a Malaysian sovereign wealth fund, and Sustainable Development Technology Canada.[44]

As of late 2016, General Fusion had received over $100 million in funding from a global syndicate of investors and the Canadian Government's Sustainable Development Technology Canada (SDTC) fund.[9]

Chrysalix Energy Venture Capital, a Vancouver-based venture capital firm, led a C$1.2 million seed round of financing for General Fusion in 2007.[3][45][46] As of 2011 General Fusion remained in Chrysalix' portfolio.[47] Other Canadian venture capital firms that participated in the seed round were GrowthWorks Capital and BDC Venture Capital.

In 2009, a consortium led by General Fusion was awarded C$13.9 million by Sustainable Development Technology Canada (SDTC) to conduct a four-year research project on "Acoustically Driven Magnetized Target Fusion";[48] SDTC is a foundation established by the Canadian government.[49] The other member of the consortium is Los Alamos National Laboratory.[48]

A 2011 Series B round raised $19.5 million from a syndicate including Bezos Expeditions, Braemar Energy Ventures, Business Development Bank of Canada, Cenovus Energy, Chrysalix Venture Capital, Entrepreneurs Fund, and Pender Ventures.[50][51]

In May 2015 the government of Malaysia's sovereign wealth fund, Khazanah Nasional Berhad, led a $27 million funding round.[52]

SDTC awarded General Fusion a further C$12.75 million in March 2016 to for the project "Demonstration of fusion energy technology" in a consortium with McGill University (Shock Wave Physics Group) and Hatch Ltd.[28]

In October 2018 Canadian Minister for Innovation, Science and Economic Development, Navdeep Bains, announced that the Canadian government's Strategic Innovation Fund would invest C$49.3 million in General Fusion.[10]

In December 2019, General Fusion successfully raised a further $65 million in Series E equity financing, which it said would permit it to finally begin the design, construction, and operation of its Fusion Demonstration Plant.[53][54]

In January 2021, the company announced funding by Shopify founder Tobias Lütke’s Thistledown Capital, bringing total funding to well over $192 million.[55]


Beginning in 2015, the firm conducted three crowdsourcing challenges through Waltham, Massachusetts-based firm Innocentive.[56]

The first challenge was Method for Sealing Anvil Under Repetitive Impacts Against Molten Metal.[56] General Fusion successfully sourced a solution for "robust seal technology" capable of withstanding extreme temperatures and repetitive hammering, so as to isolate the rams from the liquid metal that fills the sphere. The firm awarded Kirby Meacham, an MIT-trained mechanical engineer from Cleveland, Ohio, the $20,000 prize.[57]

A second challenge, Data-Driven Prediction of Plasma Performance, began in December 2015 with the aim of identifying patterns in the firm's experimental data that would allow it to further improve the performance of its plasma.[58]

The third challenge ran in March 2016, seeking a method to quickly and reliably induce a substantial current to jump a 5–10 cm gap within a few hundred microseconds, and was titled "Fast Current Switch in Plasma Device".[59] A prize of $5,000 was awarded to a post-doctoral researcher at Notre Dame, Indiana.[60]

See also[edit]


  1. ^ Wurden, Glen (22 October 2003). "Magnetized Target Fusion". Los Alamos National Laboratories. Retrieved 9 December 2020.
  2. ^ Dean, Josh (23 December 2008). "This machine might* save the world". Popular Science.
  3. ^ a b Hamilton, Tyler (20 April 2009). "Looking for a net gain in the energy sector". Toronto Star.
  4. ^ VanderKlippe, Nathan (16 November 2007). "Garage scientist aims to thwart OPEC". Financial Post. Archived from the original on 26 October 2010. Retrieved 9 December 2020. CS1 maint: discouraged parameter (link)
  5. ^ Masse, Bryson (5 May 2017). "This Vancouver Startup Is Chasing the Dream of Clean, Limitless Energy Forever". Vice. Vice Media. Retrieved 11 December 2017.
  6. ^ POWER (1 August 2018). "Fusion Power: Watching, Waiting, as Research Continues". POWER Magazine. Retrieved 25 February 2021.
  7. ^ Laberge, Michel (14 August 2018). "Magnetized Target Fusion with a Spherical Tokamak". Journal of Fusion Energy. 38: 199–203. doi:10.1007/s10894-018-0180-3. S2CID 125279953.
  8. ^ a b c Frochtzwajg, Jonathan (28 April 2016). "The secretive, billionaire-backed plans to harness fusion". Retrieved 17 January 2017.
  9. ^ a b Dawes, Terry (28 November 2016). "General Fusion to outline clean energy future for Ottawa natural resource committee". Cantech Letter. Retrieved 17 January 2017.
  10. ^ a b Boyle, Alan (26 October 2018). "Canadian government invests $38M in General Fusion to boost energy research". Geekwire. Retrieved 19 November 2018.
  11. ^ "PSFC Seminar: Acoustically-Driven Magnetized Target Fusion at General Fusion". MIT Plasma Science and Fusion Center. MIT. 18 December 2015. Retrieved 16 January 2017.
  12. ^ a b c d "General Fusion's Team, Investors and Research Partners". General Fusion. General Fusion. Retrieved 11 December 2017.
  13. ^ "Frederick W. Buckman Sr.: Executive Profile & Biography". Bloomberg. Retrieved 17 April 2017.
  14. ^ "Carol M. Browner". Department of Energy. Retrieved 17 January 2017.
  15. ^ Thomson, Jimmy (26 June 2014). "General Fusion Adds NASA, White House Talent". BCBusiness. Canada Wide Media. Retrieved 10 December 2020.
  16. ^ a b c d "Introducing alternative fusion concepts: General Fusion". EUROfusion. Retrieved 17 January 2017.
  17. ^ "Magnetic Compression and Stability of Spheromaks". Mitacs. 17 November 2014. Retrieved 17 April 2017.
  18. ^ a b c d Gibbs, Wayt (18 October 2016). "The Fusion Underground". Scientific American. 315 (5): 38–45. Bibcode:2016SciAm.315e..38G. doi:10.1038/scientificamerican1116-38. PMID 27918497.
  19. ^ a b c Peter O’Shea, Michel Laberge, Mike Donaldson, Michael Delage "Acoustically Driven Magnetized Target Fusion at General Fusion: An Overview" Archived 18 April 2017 at the Wayback Machine Poster presented at the 58th Annual Meeting of the APS Division of Plasma Physics 31 October – 4 November 2016. San Jose, California. CP10.00103
  20. ^ Hamilton, Tyler (31 July 2009). "A New Approach to Fusion". MIT Technology Review. Massachusetts Institute of Technology. Retrieved 17 January 2017.
  21. ^ O'Shea, P.; Laberge, M.; Donaldson, M.; Delage, M. (27 October 2017). "Magnetized Target Fusion At General Fusion: An Overview" (PDF). 59th Annual Meeting of the APS Division of Plasma Physics.
  22. ^ Clinard, Frank (1975). "First wall materials problems in fusion reactors". Journal of Vacuum Science and Technology. 12: 510. doi:10.1116/1.568576.
  23. ^ Grossman, Lev (October 2015). "Inside the Quest for Fusion, Clean Energy's Holy Grail". Time.
  24. ^ a b c d e Robson, A. E. (1980). "A Conceptual Design for an Imploding-Liner Fusion Reactor". Megagauss Physics and Technology. Springer US. pp. 425–436. ISBN 978-1-4684-1050-1.
  25. ^ Clery, Daniel (2014). "Fusion's Restless Pioneers". Science. 345 (6195): 370–375. Bibcode:2014Sci...345..370C. doi:10.1126/science.345.6195.370. PMID 25061186.
  26. ^ a b Cartwright, Jon. "An Independent Endeavour". Physics World. Retrieved 24 March 2017.
  27. ^ Siemon, R.; Peterson; Ryutov, D. (1999). The relevance of Magnetized Target Fusion (MTF) to practical energy production (PDF). Los Alamos National Laboratories.
  28. ^ a b c "Demonstration of fusion energy technology - clean energy". Sustainable Development Technology Canada. 19 September 2016. Retrieved 17 January 2017.
  29. ^ "Magnetized plasma fusion reactor". European Patent Office. 7 September 2006. Retrieved 16 January 2017.
  30. ^ [1], "Apparatus for Accelerating and compressing Plasma" 
  31. ^ [2], "Apparatus and Method for Generating a Vortex Cavity in a Rotating Fluid" 
  32. ^ "SYSTEM AND METHOD FOR EVAPORATING A METAL". European Patent Office. 12 May 2016. Retrieved 16 January 2017.
  33. ^ "How a Canadian fusion reactor could revolutionize the energy sector". Canadian Business - Your Source For Business News. 11 April 2014. Retrieved 17 April 2017.
  34. ^ Russ Ivanov, Patrick Carle, Neil Carter, Ken Jensen, Stephen Howard, Michel Laberge, Alex Mossman, Peter O’Shea, Adrian Wong, William Young "SPECTOR 1 Plasma as a Target for Adiabatic Compression Archived 15 December 2016 at the Wayback Machine" Poster presented at the 58th Annual Meeting of the APS Division of Plasma Physics 31 October – 4 November 2016. San Jose, California. CP10.00106
  35. ^ Ambreen, Ali (December 2016). "Reviving the Fusion Dream". PM Network. Archived from the original on 12 December 2017. Retrieved 24 March 2017.
  36. ^ "World's largest plasma injector brings commercial fusion energy a step closer". General Fusion. General Fusion, Inc. 21 December 2017. Retrieved 23 December 2017.
  37. ^ a b c d e Laberge, M.; Howard, S.; Richardson, D.; Froese, A.; Suponitsky, V.; Reynolds, M.; Plant, D. (2013). Acoustically driven Magnetized Target Fusion. IEEE 25th Symposium on Fusion Engineering. pp. 1–7. doi:10.1109/SOFE.2013.6635495. ISBN 978-1-4799-0171-5. S2CID 31681949.
  38. ^ a b "General Fusion Developing World's First Commercially Viable Fusion Power Plant for Clean Energy ·". ANSYS. 31 March 2017. Retrieved 19 May 2017.
  39. ^ "General Fusion, Microsoft team up on data analysis". Retrieved 19 May 2017.
  40. ^ Stewart, John (21 January 2015). "Innovations we need - Now, and for generations". Talk Nuclear. Retrieved 17 April 2017.
  41. ^ "Burnaby-based General Fusion Inc. Forms Research Partnership With McGill University". T-Net. T-Net British Columbia. Retrieved 17 January 2017.
  42. ^ Reynolds, Meritt; Froese, Aaron; Barsky, Sandra; Devietien, Peter; Toth, Gabor; Brennan, Dylan; Hooper, Bick (31 October 2016). "Simulation of MTF experiments at General Fusion". Bulletin of the American Physical Society. 61 (18): CP10.108. Bibcode:2016APS..DPPC10108R.
  43. ^ uk, David Lockwood. "Staff: Research Projects: Dr Eldad Avital: School of Engineering and Materials Science, Queen Mary University of London". Retrieved 17 January 2017.
  44. ^ "General Fusion's Team, Investors and Research Partners". General Fusion. General Fusion. Retrieved 11 December 2017.
  45. ^ Kanellos, Michael. "More money for fusion energy". CNET. CBS Interactive. Retrieved 11 December 2017.
  46. ^ Chrysalix is funded by a number of investors including several energy firms; its investors are listed on "Chrysalix' website" Archived 10 December 2011 at the Wayback Machine
  47. ^ "General Fusion". Retrieved 9 November 2011.
  48. ^ a b "Acoustically Driven Magnetized Fusion". SDTC. 2008. Retrieved 16 March 2017.
  49. ^ "Media Backgrounder: Sustainable Development Technology Canada". SDTC website. Retrieved 9 November 2011.
  50. ^ "Fusion lightweight gets a boost from heavyweight investors". The Globe and Mail. Retrieved 17 January 2017.
  51. ^ O'Connor, Clare. "Amazon Billionaire Bezos Backs Nuclear Fusion In $19.5 Million Round". Forbes. Retrieved 17 January 2017.
  52. ^ "General Fusion raises another $27 million to advance its reactor". Canadian Business - Your Source For Business News. 20 May 2015. Retrieved 17 January 2017.
  53. ^ "General Fusion Closes $65M of Series E Financing". Global Newswire. Retrieved 16 December 2019.
  54. ^ "Bezos-Backed Fusion Startup Raises $100 Million for Demo System". Financial Post. Retrieved 16 December 2019.
  55. ^ "Nuclear fusion tech developer General Fusion now has Shopify and Amazon founders backing it". TechCrunch. Retrieved 8 February 2021.
  56. ^ a b "General Fusion Challenge: Method for Sealing Anvil Under Repetitive Impacts Against Molten Metal". InnoCentive. Wazoku. Retrieved 17 January 2017.
  57. ^ "General Fusion Announces Winner of $20,000 Crowdsourced Engineering Challenge". T-Net. T-Net British Columbia. 17 August 2015. Retrieved 17 January 2017.
  58. ^ "General Fusion Challenge: Data-Driven Prediction of Plasma Performance". InnoCentive. Wazoku. Retrieved 17 January 2017.
  59. ^ "General Fusion Challenge: Fast Current Switch in Plasma Device". InnoCentive. Wazoku. Retrieved 17 January 2017.
  60. ^ Cassidy, Brendan (8 December 2016). "Five Things to Consider Before You Enlist the Crowd". Retrieved 17 January 2017.


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