There’s a new fusion kid on the block. His name is Nick Hawker and he carries a very big gun – 22m long. It fires a projectile at around 7km/s and aims to hit a bullseye only two atoms wide.
Fusion, of course, is nothing new. The sun has been at it for the last few billion years and is still going strong, producing vast amounts of energy – enough to keep us warm and well-lit in dark, chilly interstellar space – by smashing atoms together and converting hydrogen into helium (a process first proposed by Arthur Eddington and finally figured out by Hans Bethe).
It’s nuclear power, but not as we know it. Energy produced by fission – splitting atoms apart – is a quintessentially 20th-century invention. The disasters of Chernobyl and Fukushima – and the partial meltdown of Three Mile Island – remind us that this form of power comes out of the same school as the atom bomb dropped on Hiroshima and Nagasaki. The process at the core of both is the same: a chain reaction. Involving, the exact same material: uranium 235.
Let me stress right away that, of course, the atom bomb is designed to release the maximum amount of energy in one deeply destructive fell swoop, whereas the nuclear reactor uses fuel rods to release energy in a highly controlled and gradual way and feed it usefully into the grid. But they are both, in some sense, “nukes”, and their affinity becomes dramatically clearer in the event of a meltdown. And such reactors, even if they never go wrong, will still produce unwieldy amounts of radioactive material (with a half-life of millions of years) that we are still puzzling over what to do with.
Fusion has this in common with fission: e=mc2. Albert Einstein’s classic equation tells us that at the core of matter (m = mass) is a practically limitless source of energy (e), given that “c” is the speed of light (300,000km/s). But the big advantage of fusion (the forced marriage of particles) over fission (a spectacular divorce) is that radioactivity is close to zero.
Instead, it uses not uranium or plutonium but “light” elements like hydrogen (or versions of – deuterium and tritium) from the opposite end of the atomic table (containing only a small number of particles). It is nothing like a slow-motion bomb going off. A fusion power plant cannot go into meltdown. It serves up clean, green energy, on tap, now and forever. No centuries or millennia of burying. It is not going to run out or be held hostage by Vladimir Putin. Fusion is the dream and has been since the 1940s. Some thin k fusion might just be the future.
Some 30-odd years ago, two eminent electrochemists, Martin Fleischmann and Stanley Pons, reckoned they had achieved so-called cold fusion by which they meant getting a small sun burning in a test tube on a tabletop at room temperature. No one has since managed to replicate the experiment, and their work was roundly denounced. All the same the “low-energy nuclear reaction” project is still rumbling on. It is impossible to prove it’s impossible. But, as Hawker says, “all they have to do, if it’s real, is build something that produces power – and sell it.”
Which is just what he has done.
Hot fusion, hitherto, has proved doable but not entirely viable, or not yet. Tokamaks – huge and extremely expensive pieces of kit capable of producing temperatures of around 100 million degrees – have been sprouting up around the planet over the last few decades. The fundamental fact that they are up against is that fusing two hydrogen nuclei together is hard. They are both positively charged particles and therefore mutually repulsive. The chances are that they will bounce off one another like billiard balls or else scatter. The tokamak persuades them otherwise at these astronomically high temperatures, but only for a brief amount of time.
As recently as April of this year they were finally able to show the evidence – independently validated – that the theory works in practice and that the BFG really functions exactly the way they thought it would
Hawker gives the competition due credit. He notes that the ratio between “energy out” and “energy in” achieved by the National Ignition Facility in the US (using a laser-driven inertial confinement approach) recently hit a world record of 0.7. And he says he wouldn’t be surprised to see that number go over 1 at some point in the next year or two. In other words, the massive machines will soon be able to attain energy credit rather than be hugely in debt. They are winning. But getting this approach to be credible and commercial is still reckoned to be a distant mirage. Our very own JET tokamak in Culham, despite some impressive results, is being mothballed.
In contrast, Hawker and his crew have come up with a radically different approach to pulling off fusion and “getting it done” sooner too. “Projectile fusion” as practised at First Light, in comparison with “magnetic confinement fusion” is simpler, cheaper, and – most importantly for the immediate context – possible for a non-specialist to grasp.
At an industrial park on the edge of Oxford I met Hawker, 37, and some of his 70-strong team and I was impressed by the relaxed confidence projected by the First Light co-founder and CEO. The thing that surprised me most, however, was to learn that he was inspired by a shrimp.
A shrimp and a supernova, to be exact, but the shrimp was not so many light years away and far easier to study. What they both have in common is the ability to produce a tremendous burst of energy by means of a shock wave inside a bubble. And both emit light, whether supersized or just shrimp sized. The shrimp in question, specifically a “pistol shrimp”, which has one outsized claw which it uses to create a shockwave bubble capable of killing small fish, has given rise to a small but significant branch of physics. Hawker completed his PhD at Corpus Christi, Oxford, on the subject of “computational modelling of intense bubble collapse”. Or, in layman’s terms, how that shrimp does what it does; and how to simulate it.
Hawker has taken the concept of the pistol shrimp – or the shrimp’s claw – and converted it into an extremely long pistol, a light gas gun, with a barrel 22m long, that propels a projectile at around 7km/s into a cube of fusion fuel, turning it into thermal plasma, which is so dense that it approaches the density of the core of the sun. When the projectile hits the outer layer of the cube it produces a shock wave bubble – just like the shrimp – that then compresses the fusion fuel and under huge pressures and very high temperature for a billionth of a second causes ions to fuse and release energy.
This isn’t just theory. It isn’t a PhD anymore. Together with Yiannis Ventikos, Hawker set up First Light back in 2011 while he was still doing his PhD. As recently as April of this year they were finally able to show the evidence – independently validated – that the theory works in practice and that the BFG (or Big Friendly Gun as they call it) really functions exactly the way they thought it would and produces the amount of energy the simulation predicted.
The gun replicates some of the thermonuclear effects that other inertial fusion methods rely on powerful lasers to produce. You could think of it as a form of particle accelerator, just much more targeted, increasing the ratio of fusion to scattering, and siphoning off the resultant power. “This is uncharted,” says Hawker. “We’re off the map and I love that.”
Even if it works, the gun remains a laboratory exercise. But they do have alternative ways of producing the same impact in the form of electromagnetic launchers. I went into a room that was extremely cold but that, when they switch everything on, gets extremely hot in a small space for a short while. Imagine Stonehenge. Now take away those stone pillars and replace them with great banks of capacitors each containing some very large amount of electricity.
When they charge these up and then simultaneously discharge all of them it shoots a tremendous current – around 14 million amps – through the circuits that is focused on a tiny piece of material right at the centre of the chamber, which then hits the fusion load. It goes from zero to 15km/s in a micro-second. It could produce enough energy to power 1,000 cars to go 1,000 miles with zero pollution. Hawker is brave enough to use the word “unlimited”.
We can’t wait until 2050 for a magic bullet. We need to be decarbonising now. Otherwise, the climate will be f***ed. There are challenges and opportunities all around
First Light can boast a very cool camera that is capable of shooting a billion frames per second. At the very core of the process, it can almost capture what is happening. Atoms of deuterium (two particles) and tritium (three particles) are being rammed into one another at around 70km/s (six times escape velocity) to produce helium, with four particles. The extra particle that is thereby released is the one that produces most of the energy. And the great thing about deuterium is that you can extract it from sea water. A lot of that around.
When those reluctant atoms are forced into an unwanted union, gamma rays and free neutrons fly and generate 500 times the amount of energy you put in. But what is energy anyway? It is the “potential to perform work” as the engineers say, which doesn’t sound very exciting, until you realise that the “work” involved can be almost anything, from charging up your phone to heating your house or sending a rocket into space. Entropy – the second law of thermodynamics – is forever trying to drag us down and dissolve us into nothingness and will eventually issue in the heat death of the universe. Energy measures our level of resistance to this hypothermic fate.
Energy is everywhere and we only need to find slightly more ingenious ways to tap into it that do not involve digging great holes in the ground or sucking up and burning the innards of the world.
Everything depends on us transposing one form of energy into another. So, for example, the heat from the particles released by First Light-style fusion, captured in a lithium coolant, are, or will be used, to drive a traditional steam turbine around, which can then be translated into electricity. So it’s a “fusion” between old and new tech. “It’s just a new type of kettle essentially,” says Hawker.
And, let’s face it, there is a lot more work still to be performed, in the shape of keeping energy deprivation at bay and increasing the chances of preventing extreme terrestrial unpleasantness and mass extinctions. Hawker acknowledges that there is a clean power gap to be filled, perhaps in part by advanced modular (fission) nuclear plants alongside renewables. “All of these things are relevant. We can’t wait until 2050 for a magic bullet. We need to be decarbonising now. Otherwise, the climate will be f***ed. There are challenges and opportunities all around.”
The energy market of the future is worth trillions. Which explains why First Light has already received £77m in private equity funding.
The race is on in the dash for fusion, although there are plenty of issues around this type of energy to be worked through. Hawker expects to be able to pipe pure fusion energy into the grid sometime in the 2030s. The task at First Light is to build a fully integrated pilot plant over the next few years that will be firing pulses into thermal plasma every so often, like spark plugs in an old combustion engine, and unleashing enough raw particle power to keep the lights on in London. And quite possibly save the planet too.