inside:technology: Tokamak Energy Ltd 03 · inside:technology: 2017:edition2 ... a startup accelerator business, which was established by the founder of ... Initial business plan

Tokamak Energy’s ST40 fusion reactor is the first controlled fusion tokamak device to bedesigned, built and operated by a private venture.

inside:technology: 2017:edition2

www.ttp.com

Tokamak Energy LtdAccelerating the development of fusion power

Key facts /data:Tokamak Energy Ltd

Technology: Spherical tokamaks with high temperaturesuperconducting magnets

Established: 2009

Type: Startup

Location: Oxford

Employees: 35

CEO, Co-Founder: Dr David Kingham

After a PhD from the CavendishLaboratory, Cambridge, DavidKingham started his career in thescientific instruments industry,working for VG Scientific and VGIonex. In 1990 he joined The OxfordTrust, a charity established by SirMartin Wood, the founder of OxfordInstruments, to encourage the studyand application of science andtechnology, and then transferred toestablish and manage its commercialsubsidiary, Oxford Innovation. In2009, he co-founded TokamakEnergy, with backing from Sir MartinWood, and others.

03The company aims to accelerate the development of fusionpower by developing the latest generation of high temperaturesuperconducting magnets. The tokamak is one of several typesof magnetic confinement device, and by far the most-researchedclass for producing controlled fusion power.

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PioneersThe key architects of the START programme, Dr MikhailGryaznevich and Alan Sykes, were keen to pursue thedevelopment of the spherical reactor design, so when it wasclear that Culham would not support them they established aseparate company, Tokamak Solutions UK Ltd, the predecessorto Tokamak Energy Ltd.

David KinghamHere Dr David Kingham joined them as CEO and co-founder. He was previously director of Oxford Innovation, a startupaccelerator business, which was established by the founder ofOxford Instruments, Sir Martin Wood. Prior to Oxford Innovationhe had worked in the scientific instruments industry. It gave him a good background to understand the scientific industry and startups.

inside:technology: 2017:edition 2

www.ttp.com 04Tokamak Energy LtdAccelerating the development of fusion power

Spherical Tokamaks (ST)In the ST layout an advantageis that the toroidal magnetsare placed much closer tothe plasma, which reducesgreatly the amount of energyneeded to power themagnets in order to reachany particular level ofmagnetic field within theplasma. The other advantageis stability of the plasma. Inan ST machine, the variancefrom “inside” to “outside” ismuch larger in relative terms,and the particles spendmuch more of their time onthe “inside” (i.e. in the regionof strongest magnetic field).

Fusion Centre CulhamWork on tokamak reactor technology in the UK is carried out atthe United Kingdom Atomic Energy Authority’s (UKAEA) FusionCentre at Culham, outside Oxford. It was here in the early 1990sthey built the first experimental spherical tokamak known asSTART (Small Tight Aspect Ratio Tokamak). The leading deviceat the time at Culham was JET, a conventional tokamak whichonce produced 16MW of fusion power, and is still the world’sleading fusion research device. Despite the pre-eminence ofJET, the results from START, particularly the world record ratio ofplasma pressure to magnetic field pressure results, prompted theUK Government to release significant funding for a newprogramme – MAST (Mega-Amp Spherical Tokamak). The USGovernment, which had supported work on START, also decidedto invest in a new programme - NSTX (National Spherical ToruseXperiment) at Princeton, which it viewed as a sister device to MAST.

Rush to build STsThe success of START prompted a wave of interest in othercountries to develop their own spherical tokamaks. However,Culham Laboratory regarded JET still as the logical route tofusion power and START and MAST only as interesting scientificexperiments because of the view that it would be impossible toprovide enough current through the centre column of such acompact device to reach the exceptionally high magnetic fieldsnecessary for fusion.

CEO and co-founder, David Kingham


Initial business planThe initial business plan aimed to create a scientificinstrumentation company using spherical tokamaks withcopper electromagnets to produce neutrons. David Kingham’strack record at Oxford Innovation helped attract initialinvestment from Sir Martin Wood, Oxford Instruments andRainbow Seed Fund.

HTS breakthroughIn 2011, Kingham heard from Oxford Instruments that they hadtested a batch of the latest YBCO high-temperaturesuperconductor material from America and had beenimpressed by its quality and resilience. Around the same timeone of the potential investors in the company asked Kingham ifhe could make the business plan ‘more exciting’: here was theopportunity thought Kingham, since the new superconductingmaterial offered the ability to carry a very high current density ina high magnetic field which could solve the problem of how togenerate a fusion reaction in a compact spherical tokamak.



HTS materialsYBCO high temperature superconductors have the ability tocarry exceptionally high current densities, in excess of 100amps per square mm, in a strong magnetic field and attemperatures of around 20 kelvin (K). This generates fieldstrengths in excess of 20 tesla (T) on the magnet itself andabout 5T at the centre of the plasma. The operatingtemperature of 20K is five times higher than conventional lowtemperature superconductors – which means it can be keptcold using much less energy.


Business PlanThe business plan reduces the engineering challenge to six steps:1. Build a small prototype tokamak to demonstrate the concept.2. Build a tokamak with high temperature superconductor

magnets to prove the material.3. Reach fusion temperatures of 100 million degrees in a

compact tokamak in 2018.4. Achieve energy breakeven conditions – where energy out of

the machine is at least as much as energy in to drive fusionreactions (target date 2020).

5. Produce electricity in 2025.6. Produce electricity for the grid by 2030.

First steps In the first step the team built a ‘table-top tokamak’ - the ST25(denoting “Spherical Tokamak radius 25cm” where 25cm refersto the major radius of the device). Using conventional coppercoils this obtained first plasma in October 2012, and a maximumcalculated plasma temperature of one million degrees. This thenserved as a test bed on which to build the future devices. Theythen built a variant (ST25 1.2 HTS), using HTS coils, incollaboration with Oxford Instruments, which achieved 29 hourscontinuous plasma in a live remote demonstration during theRoyal Society Summer Science Exhibition in 2015.

ST40 testedThe company is now at the ‘third step’ where an upscaled reactordesign, the ST40, aims to achieve fusion temperatures of 100million degrees. The first milestone was reached in April 2017when it successfully created first plasma. The team is nowcompleting the installation of a full set of magnetic coils to

Hand-testedTo test the new material Dr Gryaznevich contacted friends at theCzech Technical University in Prague who agreed to let him usetheir tokamak reactor known as Golem for two weeks in thesummer of 2011. He took 25m lengths of the HTS material andwound them by hand to form the magnet as well as building acryostat from plywood to keep the HTS cold. Even in these“rough and ready” conditions he was able to prove that the newmagnetic coils could carry the necessary currents and enablethe tokamak to operate.

Defies big is betterThe founders of Tokamak Solutions felt this could address thestandard objection held by Culham and others that the centre column in an ST would be too narrow to allow a high enough

current in the magnet and require aneutron shield to protect the magnet.Given that a compact ST power plant hasa volume at least an order of magnitudesmaller than ITER – the successor to JETcurrently being built in France, which iscosting at least €16bn - what they had inmind was going to be highly disruptive.

New directionPatents based on the results from Prague were filed and Dr Kingham drew up a business plan which set out the goal to develop a spherical tokamak able to supply electricity to the grid by 2030. To reflect the new direction, the name of thecompany was changed to TokamakEnergy in 2014.




AccelerationKingham draws on his experience working at scientificinstrumentation companies where they design and build custominstruments in very tight time-frames by working on different partsof a system in parallel. At Tokamak Energy they are applying thesame approach by working on the physics of the design inparallel with the magnet development. Collaboration is also vital,says Kingham, as many in the scientific community share thedesire to speed up development. The company for example is indialogue with Princeton Plasma Physics Laboratory on sphericaltokamaks, and with the Plasma Science and Fusion Centre atMIT on HTS magnets.

Private investment Tokamak has raised private investment of £20mil, including fromOxford Instruments, the Institution of Mechanical Engineers,David Harding (the founder of Winton Capital), and Legal &General Capital. Kingham notes there are now also people andorganisations willing to invest even larger amounts in bold, earlystage technologies with global potential. He gives the example of‘Breakthrough Energy Ventures’, a fund set up by 20 of theworld’s wealthiest entrepreneurs to invest in disruptive cleanenergy companies over the next 20 years.

provide greater control over the plasma with the target to achieve15 million degrees by autumn 2017. This will then put it on trackfor plasma at 100 million degrees in 2018, which is thetemperature range required for the fusion reaction as and whenthe ideal fuel, deuterium and tritium, is added.

Magnet challengesAchieving such a powerful release of energy is now largely anengineering challenge, says Kingham.

The main challenges are:• Engineer the high temperature superconducting magnets.• Achieve a high energy confinement time for the plasma.• Demonstrate efficient current drive in the plasma.• Exhaust the heat and particles effectively without damaging

material surfaces.• Convert the neutrons to heat in a “blanket”.• Protect the superconducting magnets from neutron damage.

Location, locationTo help them meet these challenges they have been able torecruit a world-class team of superconducting magnet engineers,many of whom have worked at Oxford Instruments and/orSiemens Magnet Technology in Oxford which are the worldleaders in high-field superconducting magnets. Given theestablished view that generating fusion from a small-scalereactor is an ‘impossible challenge’ Kingham says that theirchances are made “much less impossible because the Oxfordarea has a ready-made supply chain of superconducting magnetexcellence that attracts researchers and engineers from aroundthe world”.




A ‘Wright Brothers moment’When Tokamak Energy achieves energy breakeven conditions(energy out exceeds energy in) it will be, says Kingham, “the‘Wright Brothers Moment’ for fusion”. He is confident thebreakthrough will release large-scale private investment, alongwith public funding, making the goal of fusion-powered electricityin 2025 a real possibility.

www.tokamakenergy.co.uk




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inside:technology: Tokamak Energy Ltd 03 · inside:technology: 2017:edition2 ... a startup accelerator business, which was established by the founder of ... Initial business plan