The gun is very, very big. Measuring 22m long — twice the length of a double decker bus — its chamber holds three kilograms of gunpowder. It fires a 38mm copper projectile at 20 times the speed of sound.
The target is very, very small. Encased in a solid plastic cube, a cavity 1mm in diameter holds a tiny drop of fuel. Next door, separated from the gun room by 1cm-thick blast-proof steel, nine scientists and technicians are gathered around a bank of screens making final, nervous checks. My phone has been taken away, the photographer's camera left outside. We are here to watch one of the world's most innovative attempts to achieve nuclear fusion.
This is the culmination of a decade's research and the team at this lab outside Oxford is highly protective of the commercially sensitive results. That tiny drop of fuel is made up of deuterium and tritium, two forms of hydrogen that will, the theory goes, fuse together when hit by the copper projectile. The surge of energy this reaction produces, if it works, will be enough to power an average British home for more than two years.
Silence falls before an engineer presses an innocuous-looking red button on a console and there is a muffled bang. It doesn't sound like a cannon going off. It sounds as if a dustbin has fallen over in the car park outside.
"It's not as loud as I expected," I say.
"Don't forget it's firing into a vacuum chamber," replies Nick Hawker, the 36-year-old founder and chief executive of First Light Fusion. "But look at the screen." Footage is replaying of the chamber jolting violently backwards as the copper projectile strikes, and then rebounding forwards again. "That chamber weighs two and a half tonnes."
Fusion is the holy grail of energy production. For decades it has been held up as a solution to the world's energy problems. If it works, virtually limitless, clean, carbon-free energy would be the result. At a time when the world depends on Russia for much of its gas and on questionable regimes in the Middle East for its oil, any technology that can sever this reliance and provide energy independence carries huge geopolitical benefits.
Fusion works by mimicking the reaction that takes place at the centre of the sun. Two atoms of hydrogen, the most abundant element in the universe, are fused together to form helium. As they join, a single neutron spins off, the reaction creating a huge surge of energy, which scientists hope will one day soon drive turbines to provide electricity in power plants across the world.
Unlike nuclear fission — the reaction at the heart of established nuclear power, which works by splitting atoms apart rather than joining them together — fusion carries few significant safety concerns and generates very little radioactive waste. And whereas the uranium or plutonium that powers fission is unstable, difficult to produce and even harder to dispose of, fusion does not have that problem. Tritium and deuterium, the two forms of hydrogen used in the fusion process, are easy to secure at the volumes required.
Professor Ian Chapman, the CEO of the UK Atomic Energy Authority, says: "One of the beauties of fusion is that you get an enormous power output for very little input. With fusion, all the fuel I will need for the rest of my life is the water in the bathtub and the lithium in two laptop batteries — the root fuel is deuterium, which you get from water, and lithium, which you use to breed the tritium."
Fusion offers a panacea, a solution to many of our energy problems. But it has been offering us this gift for the better part of a century, the outcome always just out of reach. Scientists have been hailing the potential of fusion since the Cambridge physicist Ernest Rutherford in 1934 described the "enormous effect" that could be produced by converting deuterium into helium.
A little over two decades later, in January 1958, a team of scientists at the Zeta project at Harwell in Oxfordshire — just 20 miles south of the industrial park where First Light Fusion now runs its operations — proclaimed they had achieved fusion. "A sun of our own — and it's made in Britain!" said the front page of the now defunct tabloid the Daily Sketch the next day. "Unlimited fuel for millions of years," said the Daily Mail.
Those scientists, however, later had to backtrack, admitting their announcement had been premature. It became known as the Zeta fiasco, and still plays on the minds of fusion scientists today. It is one of the reasons for secrecy in the control room at First Light Fusion. "We won't announce the results until it has all been peer-reviewed and everything has been checked and verified," Hawker says.
Despite the embarrassing events of 1958, fusion has been demonstrated many times since. It works in theory, and it works in practice. Hydrogen atoms can be fused together to form helium, and a surge of energy is produced as a result. That is not in doubt. But despite decades of experiments, despite its huge potential, the fusion process has never actually been used to generate usable electricity. Fusion, the joke goes, is always no more than 30 years away from delivering on its promise.
Chapman describes this pursuit as a "quest". In February he said in a speech: "It really matters to our planet and to our people. But a quest is characterised by challenges to hurdle, by adversities to overcome, often obstacles that you don't even imagine at the start of the journey."
Even when judged on these terms, this odyssey has been particularly epic. Fusion has been around so long that it has gone out of fashion. There are early signs, though, that it may be creeping back into vogue. It was once the domain of huge government projects. But First Light Fusion is one of a number of small-scale start-ups experimenting with different technical approaches. The number of private companies pursuing fusion globally has doubled since 2014, according to the Fusion Industry Association. Between them they have attracted investment of £3 billion (NZ$5.7b).
Hawker believes his approach — projectile fusion — has a faster trajectory than other techniques. While others experiment with lasers, bubbles and huge magnets, Hawker's team is the only one in the world going down this track. Unlike others, the team has not yet demonstrated fusion — but they are convinced they will soon. And when they do, Hawker believes they will be ahead of the pack in the bid to generate electricity.
"I think we have a credible proposal to solve the physics problem this decade and to build a plant in the next decade," he says. So how is his approach so different? No matter how you go about it, all fusion techniques aim to replicate the process taking place at the centre of the sun — fusing hydrogen into helium. And this is a significant engineering challenge. In the sun hydrogen fuses under immense gravity. On Earth scientists have to take a different approach.
Most attempt to do this using a machine called a tokamak, a huge doughnut-shaped structure that heats a gas of charged hydrogen atoms to 150 million degrees Celsius, 10 times the heat at the centre of the sun. It does this by simultaneously energising, electrifying and firing atoms at the mix. This charged cloud is known as a plasma — sometimes called the fourth state of matter. When in a solid, liquid or gaseous state, electrons stay put, remaining with the nucleus of the atom to which they belong. In a plasma, electrons wander freely, passing between the different nuclei. It is in this high-energy, high-temperature environment that fusion takes place.
But tokamaks require a huge energy input, partly because the electromagnets they use to control a cloud of superhot charged material must be enormous so as not to melt the walls of the plant. The process is so energy intensive that every time scientists run an experiment they have to warn the National Grid in advance.
In February scientists announced that the world's largest tokamak, the Joint European Torus (Jet), a fusion reactor that has been operating since 1983 in Culham, another centre of fusion science in the Oxfordshire countryside, had broken the world record for energy produced in a sustained fusion reaction. It held the reaction for more than five seconds, releasing 59 megajoules of heat energy — nearly three times the previous record of 22 megajoules, which had been set at the same facility back in 1997.
It was a milestone achievement. Over those five seconds it provided an average of 11 megawatts, sufficient briefly to power a small town. But powering the reaction required an input of 30 megawatts. Creating the reaction requires far more energy than it generates. Scientists stress that the aim at Culham was never to demonstrate energy efficiency but to show proof of concept.
The economies of scale using the tokamak approach mean the bigger the power plant, the more likely it is to be energy efficient. The current best hope of doing this lies in a giant machine called Iter, under construction in the south of France. Involving 35 countries and a price tag of more than £17b, it has been in the planning for years and is not likely to achieve fusion before 2035.
And when is this approach likely to lead to electricity being produced for the grid, to power microwaves, kettles and lights? According to the Iter organisation, by the end of 2050.
The world's biggest fusion project, in other words, is still 30 years away from delivering. First Light Fusion, operating in an industrial park outside the village of Kidlington, north of Oxford, has taken a radically different approach. Instead of producing a giant cloud of heated charged particles, the company is working on firing a projectile so fast at the hydrogen atoms that they implode, creating plasma and fusing under the immense pressure. This approach — called inertial containment — means magnets are not needed.
"You get the temperature by squashing the fuel really quickly," Hawker says. "It's a big, simple, stupid machine. It just whacks it." The £1.1 million gun he uses to do this is nicknamed the BFG, or Big Friendly Gun. It is the third-biggest gun of its type in Europe. The only bigger ones are used to test the materials on spacecraft and satellites, to ensure they can withstand being hit by space junk or a passing asteroid.
Hawker's project also sounds like something out of this world. But it is gathering pace and attention. It is also gathering investment. In February First Light Fusion raised £34m in its third investment round, following input of £23m in 2015 and £19m in 2020. Investors do not view Hawker as a crusader on a fruitless quest, but as someone who might bring them a return.
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Hawker's vision may sound like science fiction, but it started with natural history. While an undergraduate at Oxford University, where he was studying mechanical engineering, he became fascinated by the hunting technique of a remarkable marine animal called a pistol shrimp. This shrimp has one oversized claw, which it snaps shut so fast that it produces a shock wave that stuns its prey. "It puts the water under so much stress that it forms bubbles," Hawker says. "The shock wave and the bubble interact, and you get these bright flashes of light."
These flashes are formed when the bubbles collapse, putting the water vapour they contain under such high pressure that they become a superhot, charged cloud. They form plasma.
Hawker started modelling the forces at play in a pistol shrimp-induced shock wave, working with the engineering professor Yiannis Ventikos. That might have been as far as it went, because when Ventikos asked him to continue his work for a PhD, Hawker initially refused. "I was in a long-distance relationship at the time — I didn't want to stay in Oxford, I was a bit sick of it," he says. "But I didn't actually ask him what the PhD would entail and after a week or so I went back and we got talking properly."
Ventikos persuaded Hawker to carry on his pistol shrimp research, with an eye on using the findings for a new approach to fusion. The professor agreed that Hawker could study remotely. He moved in with his girlfriend, Helen, in Manchester, where she was studying at the Royal Northern College of Music. "I came down to Oxford once every few weeks. I slept on floors and sofas. And the question going into my PhD was can we model this, can we understand it? Can we push it? Can we get higher and higher temperatures? I just wanted to do something in the real world and solve an actual problem," says Hawker, who gained his love of science while at Harrogate Grammar, his local comprehensive.
"I was very lucky, it was a very good school. I love physics, and I was always very good at maths. But I wanted to be an engineer. The thing that really attracted me to this project — and still really motivates me now — is that it's a new idea for fusion. It's not raking over something that was done slightly differently in the past. This is really new ground, new possibilities. I love that feeling of going to work and thinking we're the only people in the world who know this fact we have learnt today, pushing beyond the edge of human knowledge."
Ventikos is still involved in the company, chairing the advisory board. Professor Ron Roy, the head of the engineering department at Oxford, is also on the board. But what happened with Helen? "We have two kids now," Hawker says, grinning.
By 2011, with a year of his PhD still to go, Hawker had demonstrated via his computer models that he could recreate the pistol shrimp process and was convinced he could make plasma. He founded his company and began looking for investment, initially via the university's technology transfer office. "We raised £1m to start with. But we had some milestones to hit."
Having managed to simulate the physical forces required on a screen, he now had to replicate it in real life. He had to show he could create plasma. "So we built an experiment," he says. In his university lab he started firing projectiles to recreate the pressure seen between a shrimp's claws. "We did everything on a shoestring. We used bits of old carpet to catch the projectiles. Our gun was an old navy artillery barrel, which had somehow ended up at the engineering department in Oxford. It was being used for impact experiments on armour plating and stuff like that."
But initially it just didn't work. "We created a set-up but we tried to make the maximum amount of it survive after each shot so we could reuse it, because if we were destroying it every time it was going to cost us a lot of money, and we didn't have much."
In late 2012, with deadlines approaching, he called a halt to the tests and sat down with his fellow researchers. "We booked one of the lecture theatres in the engineering department for the whole day and we just stood at whiteboards and talked through how we were going to change it. Because it was not working."
Previously he had been trying to stop the projectile smashing up the target and equipment. But it did not generate enough energy. "We changed the whole thing and called it the 'fly through set-up'. We decided to let the whole lot smash through the back."
It worked first time. "The whole lot just smashed through the back and debris went everywhere." But watching on the sensors, something showed up on the screen as the projectile hit the target with its tiny drop of fuel. "It was just before the debris came flying through," he says. A blue flash of light appeared exactly where he had modelled it would. He shows me the image captured by those sensors. "The blue you see is the light emitted from the plasma during the collapse of the cavity." He had done it, he had created plasma.
Nowadays the working environment at First Light is very different. "The bits of carpet have gone," he says. In 2015 the company moved out of the university lab and to its premises a few miles away, near Kidlington. "That was the moment when we really came out from under the wing of the university." His company now employs 67 staff. His chief operating officer, Gianluca Pisanello, joined after 14 years as a chief engineer on Formula One teams. He also employs a squad of physicists, engineers and modellers, plus two former navy weapons engineers to maintain and operate the BFG.
Despite the funding, the staff of talented scientists and the fancy machinery, though, Hawker has not yet actually demonstrated fusion. The drops of tritium and deuterium, the hydrogen isotopes being smashed by the huge gun in his lab, remain separate — they have not yet fused. And that is what the nervous scientists in the control room are checking. Have they done it this time?
"We try it every day," he says. "Now we're on the crunchy part, the physics problem. You fix each issue, but you don't know until you have done it whether it is the last issue and you've got the result."
They experiment with different projectiles — copper, aluminium, tungsten. And they tweak the design of the target. His team found that putting three cavities inside the block of plastic instead of one significantly increased the pressure exerted on the fuel. Two large cavities collapse on impact, creating a double shock wave that enclose the final target in a pincer movement. "But why three cavities?" Hawker says. "Why not four, why not nine?"
His team has used artificial intelligence to improve the target configuration, but he will not divulge the design they are using at the moment. That is understandable. If and when the company goes into production phase, these plastic targets will be the consumable product they sell. The designs have improved so much that, according to his simulations, when the company achieves fusion the yield will be 15 orders of magnitude higher with the current design than the one they started with.
"We've gone past the limits of what I thought was possible several times," he says. "We just keep finding these massive improvements."
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If he succeeds, if fusion is achieved today, or tomorrow, or next week or next year, what then? The next stage is to show that this approach can achieve "energy gain" — that it can produce more energy than it requires. No fusion experiment in the world has yet done that. I joke, not for the first time, about fusion always being 30 years away. But Hawker patiently brushes aside the jibe. "I'm confident we can demonstrate gain this decade," he says.
This is what Hawker spends much of his time working on — how to generate electricity in an efficient way. "We're currently an invention machine but we will have to become an engineering machine," he says. And that is where he believes First Light Fusion has an advantage over the big, unwieldy government projects. "Everything you need for this approach you can get from a catalogue," he says. "It is just stuff. There is no unobtainium. A lot of other fusion schemes rely on a magic material that doesn't exist yet. I want the plant design to be as boring as possible. Take the steel — you can look it up on the internet. It's called P91, nuclear-approved steel. You can find utterly boring documents on how to weld it."
The power plants Hawker envisages — tragically, one might think — will not involve the huge gun he has in his lab. That is just for experiments. Instead it will use an electromagnetic launcher to fire the projectile. His team has already built one such launcher, a £3.6m device called Machine 3. "It works like an old-school camera flash," he says, climbing a ladder on top of the machine. "It stores up energy very slowly and then discharges it very quickly, like the flash of a camera."
It is massive, 12m across and 4m tall, filling a large room like a gigantic, squatting spider. It takes 50 seconds to charge its 192 capacitors; then, in two millionths of a second, it discharges 200,000 volts, the equivalent of 500 simultaneous lightning strikes. This huge surge of power is used to fire a projectile at even greater speeds than the gun next door. Yet this machine plugs into a standard 32-amp socket. Down the road in Culham they have to call the National Grid to warn them they are about to drain 40 megawatts (or 40,000 kilowatts) of power from it. Here, Machine 3 requires just 25 kilowatts of electricity to charge. It is starting to become clear why investors are so interested.
Eventually, when fusion has been demonstrated and energy gain achieved, equipment like Machine 3 will be used to fire a projectile every 30 seconds, in the same way that an internal combustion engine repeatedly ignites fuel in a car. When the projectile hits the fusion fuel, it will release a surge of energy that heats a pool of liquid lithium. That, in turn, will boil water via a heat exchanger, and the resulting steam will drive a turbine to generate electricity.
Hawker is planning a series of small, modular power plants, each providing 150 megawatts of electric power. By comparison the huge nuclear-fission power station planned for Hinkley Point C in Somerset will provide 3260 megawatts. "Smaller units gives you design flexibility, which is really valuable," he says.
So what is the aim of all this? With renewable energy now so established and so cheap, do we really need fusion energy?"If you look at projections for solar and wind in the future, they look like they can meet the electricity we need today," Hawker says. "But our need for electricity is going to increase massively as we decarbonise transport and heavy industry and so on. We are going to need a lot more clean energy and we are going to need different technologies to supply it."
In a world where electricity increasingly looks like the greenest option — with electric heat pumps set to replace gas boilers to warm our homes and electric cars set to replace petrol and diesel — demand is, indeed, set to soar. When we are imposing sanctions on Vladimir Putin with one hand and buying his gas with the other, home-grown energy is more important than ever.
And with energy bills set to soar 50 per cent next week, and possibly further later this year, cheap, sustainable energy is much needed. Fusion may have always been 30 years away in the past, but if Hawker and his team have anything to do with it, the future is closer than ever before. But he insists other innovators are also reeling it in. "I don't think there's going to be one technology for fusion," he says. "I think deployment, our ability to build the plants as fast as possible, will be the rate-limiting step. So I think there will be multiple fusion technologies."
For now, though, he has to show that it can work, that his vision that started with the claw of a shrimp can give the world clean energy. Time to load up the gun and give it another shot.
The race to fusion: four more contenders
Tokamak magnetic fusion
A vast cloud of plasma is superheated in a tokamak — a huge doughnut-shaped vacuum chamber — until fusion is achieved. The cloud is held in place with massive electromagnets. This approach has been achieving fusion for decades and holds the record for energy output — 59 megajoules — achieved at the Joint European Torus facility in Oxfordshire, above, in 2021 (although it took a much higher energy input to achieve it). A much bigger reactor, the £17b Iter project in France, is backed by 35 countries as the best bet to deliver large-scale fusion, but is years from completion.
Inertial confinement fusion
The technique closest in approach to the inertial containment method used at First Light, but, instead of a projectile, using lasers. A tiny droplet of fuel held inside a gold or lead cylinder is bombarded with laser beams. Last August the National Ignition Facility in the US came closest to achieving a record energy gain, generating 1.3 megajoules of power with an input of 1.9 megajoules, a ratio of 0.7.
Magnetised target fusion
A hybrid approach where magnetic fields are used to contain a cloud of plasma, which is then heated and compressed using lasers or pistons. It has been talked about in theoretical terms for years, but General Fusion, a Canadian firm that uses the approach, has attracted more than US$200m (NZ$290m) of investment, and last year agreed to build its first demonstration plant at Culham in Oxfordshire, in partnership with the UK Atomic Energy Authority.
Z-pinch
Powerful magnetic fields put a cloud of plasma under huge pressure until it fuses. This is the modern-day successor to the UK Zeta project, which in 1958 prematurely announced it had achieved fusion but was later discredited. The 21st-century versions attempt fusion using magnetic coils, while others achieve the magnetic forces by sending pulses of electric current in columns through the plasma. Zap Energy, a University of Washington spin-out, achieved fusion in 2018.
Written by: Ben Spencer
© The Times of London
