Fusion energy: Mastering plasma hotter than the centre of the Sun with tiny tokamaks

International Business Times By Richard Dinan | March 9, 2017

Using smaller reactors, Applied Fusion Systems hopes to move nuclear fusion forward within four to six years.

There is a famous saying in the fusion community: “Fusion is easy; plasma physics is hard.”

Fusion has had a rough PR history. In 1989, Martin Fleischmann (then one of the world’s leading electrochemists) and Stanley Pons claimed that they could produce nuclear fusion in a bottle at room temperature. There was immediately a rush to replicate their findings of excess heat caused by fusion reactions.

These results turned out to be extremely hard to replicate and there was a big backlash against the then-respected physicists. Cold fusion was famed for being a myth. Hot fusion is the confining of a ‘plasma’, which is the fourth state of matter – a gas-like state of ionized particles. As the plasma is charged, it can be controlled and confined in a vacuum using powerful electromagnets.

Heat is a measurement of the speed of which the particles are moving. In “hot fusion”, ions in the plasma collide and can fuse, liberating nature’s “strong force”. Neutrons are a product of this reaction and their kinetic energy can be captured as heat which, in turn, can be used to drive a conventional turbine and generate electricity.

This method of fusion has had substantially more success in a device called a tokamak. This is a doughnut shaped vacuum vessel and one was constructed in Culham, England, called JET (Joint European Tourus), which in 1991 achieved the world’s first controlled release of fusion power.

Despite this success, Fusion was proving to be extremely expensive and complicated due to problems controlling the confined plasma. Physicists in 1991 did not have access to modern super-computing powers and the reactions within the plasma created the need for vast calculations, which were forever changing with every further reaction that occurred.

Fusion requires temperatures hotter than the center of the sunNASA/STEREO/Helioviewer

The problem was that to get fusion reactions to occur within the plasma, you need extremely high temperatures (300M Kelvin). That’s much hotter than the center of the sun. The plasma suffers “vibrations” under powerful magnetic confinement in the tokamaks, and these vibrations stop the reaction. This gave way to the physics of “gyrokinetics” and “magneto hydrodynamics”, which are very complex studies of the understanding of plasma physics necessary to master nuclear fusion in tokamaks.

Of course there were other setbacks. Fusion is not a weapon unlike fission, which we utilise in today’s nuclear power stations. There also wasn’t as much demand for clean energy then as there is now. Fusion required huge funding and was still known to be very hard to achieve. Fusion also desperately needed development funding, but governments were in no hurry to pledge billions of dollars to the cause.

Luckily for fusion scientists, when achieved, fusion is capable of producing a million times more energy than a combustion or chemical reaction, but without producing long lived, radioactive waste or the use of materials like uranium.

So big is the payoff that it managed to survive the redundancy of government pragmatism. Finally, following the success at JET and after many years of deliberation and time wasting, seven countries signed up to fund ITER in 2006. The International, thermo-nuclear experimental reactor was given a budget of €5bn (£4.3bn).

To pledge this funding, governments wanted to be certain that it would work, and it must produce more energy than it uses up. Once this is demonstrated, then they can start commissioning and building fusion power stations.

The tokamak in ITERITER

ITER predicted it to produce 10 times more power than will be required to run it. Scientists had to convince government funding powers that ITER would work. They had to navigate around the problem of these vibrations. One way to do this was size. In short, scientists found that the larger the reactor, the less of a problem these plasma vibrations were proving to be.

So one way to satisfy governments of the success of ITER was to make it large – almost 60ft tall and weighing over 23,000 tonnes.

Essentially, ITER was made so large as a direct result of a lack of understanding of the control and behaviour of plasma. Originally based on a 1990s design and without today’s supercomputing powers, size was the only way to guarantee its success.

Since then, ITER’s budget has grown to €12bn (£10.4bn) and the project is not set to turn on until 2040 after suffering many long setbacks. Again, this is largely due to the size of the project, the many contractors and the suggested improvements made along the way, as modern technology taught us more about this science. The perfect storm for an organisational catastrophe.

ITER has become an enormous sector funding drain, as governments are obviously reluctant to invest more into fusion until their €12bn experiment has turned on – and succeeded. Ultimately, there is no fusion funding from governments until 2040. This is a shame.

As an entrepreneur and non-scientist, I believe the real success is funding fusion. Private companies must step up. Modern supercomputing has revealed so much about plasma physics. It has shown us that the biggest breakthrough in fusion will not be stronger rare earth magnets, or more advanced materials, but understanding of the behaviour of plasma under confinement.

This will pave the way for modern, smaller reactor design. Smaller is cheaper and faster by default. Smaller reactors can be prototyped more efficiently, and it is my belief that this is the only way meaningful breakthroughs will be made in this sector before ITER turns on in 2040 (or longer).

That’s why I’ve founded Applied Fusion Systems. We are now in the process of process of privately financing the construction of our own British made Tokamak reactor – STAR (Small Toroidal Atomic Reactor).

The designers behind STAR have compiled elements from some of the most successful reactors over the past 20 years and applied the very latest technologies, combined with a cutting edge understanding of plasma physics.

We hope that we can get the £200m funding we need to construct two spherical tokomak nuclear fusion reactors, with the intentions to generate data and results within the next four to six years.

Applied Fusion Systems’ goal is to make meaningful contributions to one of the most challenging and important technologies our generation has a responsibility to master.